Car tire thread for experience -not debate
- Thread starter oldbear
- Start date
Ramseybella
Well-Known Member
Re: Car tire?
One can only try it and see how it works, not like your going deep sea diving in a 55 gallon drum with lead bricks strapped to it wearing a mask and Snorkel.
One can only try it and see how it works, not like your going deep sea diving in a 55 gallon drum with lead bricks strapped to it wearing a mask and Snorkel.
EricV
Riding, farkling, riding...
2011 Site Supporter
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Re: Car tire?
[Snipped by CW . . . ]
. . . there have been more tire related accidents with GL1800s two up and loaded [font=verdana, arial, helvetica, sans-serif]with motorcycle tires[/font] than probably any other bike. The bike, loaded and two up, is over the moto tire load rating and it heats up. On a hot day, it can explode while riding. (don't believe me, read the Wing forums) With the advent of TPMS, riders are actually seeing the temps climb well into danger levels, which btw, increases tire wear too. Sometimes a LOT. A run flat car tire solves these issues as it has a higher load rating and runs cooler. Lighter bikes like some crusiers and the FJR do not benefit from the stiff sidewalls on run flat tires and are better off using a regular all season car tire, for those that desire to go Darkside.
I never had any issues in handling with the CT other than minor oddities in very specific conditions like grooved/rutted pavement from studded tires or off pavement tire ruts. It likes to track in them more than a narrower moto tire. Transitions from pavement to driveways where there is a step up or down makes the bike want to stand up a bit, but is easily compensated for and when you know what's going to happen, is easy to deal with. It will amplify a worn front tire. Bar pressure for turn in is increased, but quickly gotten used to. You lose that "thought controlled steering" feel of a new set of moto tires and will never have that with the CT. OTOH, you lose that feeling pretty quick with new moto tires too, it's just a slower progression that you only notice when the tires are more worn.
In many conditions, sand on the road, tar snakes, dirt, gravel, etc, the performance of the CT is far superior than the moto tire. More sipes, more tread blocks = no stepping out in a corner just because of a little sand or debris, or tar snakes. Off pavement the CT rocks and will go places even dual sports with knobbies don't want to. But some of that is rider too.
You can corner harder with the CT than normal sport-touring rubber. I am not suggesting that some sticky track tire can't do better, but on the street, at street legal and slightly above, you simply have more traction with the CT. At somewhere around 120-140, depending on bike, load, road/track conditions, you get a weave that can be disconcerting. For most of us, that's not an issue on the street. Typical tire pressures are about the same as a light sports car, 29-32 psi, varied by rider preferences, tire, bike, loading, etc.
Again, yes it's strange and different from what you know. No, it's not for everyone. Yes, it really is perfectly safe. No, there are no insurance issues. No, no tire manufacturer is going to tell you it's ok to do. No, no moto tire manufacturer is going to sell you a radial moto tire that lasts 25k, (like bias ply moto tires typically did), because you keep buying the ones that wear out in less than 10k. Yes, I really did get 37k from two different all season car tires mounted on my FJR, and changed both early, before reaching the wear bars, because I had a longer ride ahead than I thought the tire would last. Not unlike what many of us do for moto tires, just less often.
FWIW, there were two FJRs in the recent IBR that did not run CTs, and the rest ran CTs. Both of the moto tire riders needed a new rear tire during the rally. None of the CT guys did.
Here is some perspective. If you can identify with this, you might consider a CT on a bike. If you can't, there is no need to bother yourself further with the idea.
You buy a new set of tires and have them mounted and balanced. Tires you normally get 12k from on the rear, (to wear bars). 12 days later you return to the bike shop to have a new rear tire mounted and balanced. The shop asks you if there was a problem with the tire? You reply, "no, it just wore out". They get a funny look on their face and ask how many miles are on the tire? "12,800 and a little" you reply.
One fellow that told me he couldn't understand why I would put a CT on a motorcycle also told me that, for safety reasons, he mounts up a fresh set of moto tires on his bikes every season, whether he needs them or not. He just couldn't understand the cost being an issue. After I explained I had gone thru 5 rear tires and 4 fronts the prior season, he started to appreciate that we had different needs.
[Snipped by CW . . . ]
. . . there have been more tire related accidents with GL1800s two up and loaded [font=verdana, arial, helvetica, sans-serif]with motorcycle tires[/font] than probably any other bike. The bike, loaded and two up, is over the moto tire load rating and it heats up. On a hot day, it can explode while riding. (don't believe me, read the Wing forums) With the advent of TPMS, riders are actually seeing the temps climb well into danger levels, which btw, increases tire wear too. Sometimes a LOT. A run flat car tire solves these issues as it has a higher load rating and runs cooler. Lighter bikes like some crusiers and the FJR do not benefit from the stiff sidewalls on run flat tires and are better off using a regular all season car tire, for those that desire to go Darkside.
I never had any issues in handling with the CT other than minor oddities in very specific conditions like grooved/rutted pavement from studded tires or off pavement tire ruts. It likes to track in them more than a narrower moto tire. Transitions from pavement to driveways where there is a step up or down makes the bike want to stand up a bit, but is easily compensated for and when you know what's going to happen, is easy to deal with. It will amplify a worn front tire. Bar pressure for turn in is increased, but quickly gotten used to. You lose that "thought controlled steering" feel of a new set of moto tires and will never have that with the CT. OTOH, you lose that feeling pretty quick with new moto tires too, it's just a slower progression that you only notice when the tires are more worn.
In many conditions, sand on the road, tar snakes, dirt, gravel, etc, the performance of the CT is far superior than the moto tire. More sipes, more tread blocks = no stepping out in a corner just because of a little sand or debris, or tar snakes. Off pavement the CT rocks and will go places even dual sports with knobbies don't want to. But some of that is rider too.
You can corner harder with the CT than normal sport-touring rubber. I am not suggesting that some sticky track tire can't do better, but on the street, at street legal and slightly above, you simply have more traction with the CT. At somewhere around 120-140, depending on bike, load, road/track conditions, you get a weave that can be disconcerting. For most of us, that's not an issue on the street. Typical tire pressures are about the same as a light sports car, 29-32 psi, varied by rider preferences, tire, bike, loading, etc.
Again, yes it's strange and different from what you know. No, it's not for everyone. Yes, it really is perfectly safe. No, there are no insurance issues. No, no tire manufacturer is going to tell you it's ok to do. No, no moto tire manufacturer is going to sell you a radial moto tire that lasts 25k, (like bias ply moto tires typically did), because you keep buying the ones that wear out in less than 10k. Yes, I really did get 37k from two different all season car tires mounted on my FJR, and changed both early, before reaching the wear bars, because I had a longer ride ahead than I thought the tire would last. Not unlike what many of us do for moto tires, just less often.
FWIW, there were two FJRs in the recent IBR that did not run CTs, and the rest ran CTs. Both of the moto tire riders needed a new rear tire during the rally. None of the CT guys did.
Here is some perspective. If you can identify with this, you might consider a CT on a bike. If you can't, there is no need to bother yourself further with the idea.
You buy a new set of tires and have them mounted and balanced. Tires you normally get 12k from on the rear, (to wear bars). 12 days later you return to the bike shop to have a new rear tire mounted and balanced. The shop asks you if there was a problem with the tire? You reply, "no, it just wore out". They get a funny look on their face and ask how many miles are on the tire? "12,800 and a little" you reply.
One fellow that told me he couldn't understand why I would put a CT on a motorcycle also told me that, for safety reasons, he mounts up a fresh set of moto tires on his bikes every season, whether he needs them or not. He just couldn't understand the cost being an issue. After I explained I had gone thru 5 rear tires and 4 fronts the prior season, he started to appreciate that we had different needs.
RCinNC
Well-Known Member
Re: Car tire?
[snipped by CW . . . ]
I'm on several different motorcycle forums, and the darkside topic has been discussed ad nauseam. One claim I don't see very often is that a car tire handles better than a motorcycle tire; the advantage most often cited by darksiders is the longevity of the tire (some claims I've seen are that they also handle better in wet conditions).
Obviously, a car tire isn't the ideal profile for a motorcycle, which I'm sure is why major motorcycle tire manufacturers don't make them. To me, it seems that the point being made by most darksiders is that using a car tire offers some advantages over a motorcycle tire (50,000 miles as opposed to 5,000), and that using a car tire isn't inherently dangerous. I doubt that many darksiders (at least those that are being objective) would say that a car tire handles better than, say, a Pilot Road, but I'm just as sure that the darkside riders will say that their car tires don't handle unacceptably worse than a Pilot Road, and that it will outlast a Pilot Road by about 10 times. There are countless first hand accounts of guys who have used car tires wiith no issues to dismiss their experiences offhand.
[snipped by CW . . . ]
I'm on several different motorcycle forums, and the darkside topic has been discussed ad nauseam. One claim I don't see very often is that a car tire handles better than a motorcycle tire; the advantage most often cited by darksiders is the longevity of the tire (some claims I've seen are that they also handle better in wet conditions).
Obviously, a car tire isn't the ideal profile for a motorcycle, which I'm sure is why major motorcycle tire manufacturers don't make them. To me, it seems that the point being made by most darksiders is that using a car tire offers some advantages over a motorcycle tire (50,000 miles as opposed to 5,000), and that using a car tire isn't inherently dangerous. I doubt that many darksiders (at least those that are being objective) would say that a car tire handles better than, say, a Pilot Road, but I'm just as sure that the darkside riders will say that their car tires don't handle unacceptably worse than a Pilot Road, and that it will outlast a Pilot Road by about 10 times. There are countless first hand accounts of guys who have used car tires wiith no issues to dismiss their experiences offhand.
Re: Car tire?
This does not have a yes/no or black/white answer. Some countries require complete compliance and absolutely only OEM specified parts may be used. Insurance companies may refuse payment and liability can be disastrous. In the US and some other countries, the relation of the non-OEM modification has to be related to the loss.
RIVA said:
This does not have a yes/no or black/white answer. Some countries require complete compliance and absolutely only OEM specified parts may be used. Insurance companies may refuse payment and liability can be disastrous. In the US and some other countries, the relation of the non-OEM modification has to be related to the loss.
Re: Car tire?
This thread was locked because of the amount of speculation and rampant argument going on. This post is about how this thread has had posts deleted, others shortened (as marked for transparency), and is intended to be kept up. The bottom line is to keep it factual in this thread, as only the speculation in the original post will be kept to illustrate the level of controversy which the subject can introduce. If you have history and experience, feel free to put it here. Go to the Debate Room or one of many other forums to post speculation, as argumentative posts in the Tech and Modifications areas may be snipped.
fwiw about my background to cut some posts and snip others, I'm a systems engineering accident investigator who regularly examines ABS systems (1 in the last month), reconstructs and examines tires (4 in the last month), and examines skid marks, sometimes teaching about those subjects. I've done oil plate documentation regarding tread contact, am aware of the physics at both the tire and vehicle levels, and know who to call when I see something new.
Simply discussing how much contact exists when leaned over, or about how hard tread compounds may be, does NOT tell the whole story. The fact is that car tires have been used and used successfully since the beginning of motorcycles. Model A Ford tires were used extensively in the 1930s and VW tires later, long before we got the specialized tires we now have. Some touring motorcycles such as Goldwings have car tires installed for long life and/or heavier load capability. Sidecar motorcycles with car tires occasionally get run without the hack and car tires are very common in long distance competition.
Just like any other tire design, car tires on motorcycles have strengths and weaknesses affecting each aspect of the design trade-offs. Any change in tire profile and construction does change handling which affects handling, even between types of motorcycle-specific tires such as a road racing V and a touring oval. Stark differences exist between the design and construction of motorcycle road racing tires and thick carcass off-road desert tires. Neither of those have been optimized to long distance use in the way that car tires have been.
Car tires on a motorcycle will result in an integrated vehicle which is different than the set of design trade-offs which the vehicle designers intended. Doing so can be dangerous. This means that the rider is a test pilot of a new set of vehicle characteristics unless he has information which the original designers did not have. To have this information, the owner must either approach opening the performance envelope gradually, like the initial tester of any new vehicle, or collect experience about the same model tire on the same vehicle in the same types of use from people who can relate their experience.
So with the intent of sharing information, rather than hype and argument, and recognizing that all modifications are the choice and potential risk of the individual doing so, this thread is re-opened.
Bob / Checkswrecks
This thread was locked because of the amount of speculation and rampant argument going on. This post is about how this thread has had posts deleted, others shortened (as marked for transparency), and is intended to be kept up. The bottom line is to keep it factual in this thread, as only the speculation in the original post will be kept to illustrate the level of controversy which the subject can introduce. If you have history and experience, feel free to put it here. Go to the Debate Room or one of many other forums to post speculation, as argumentative posts in the Tech and Modifications areas may be snipped.
fwiw about my background to cut some posts and snip others, I'm a systems engineering accident investigator who regularly examines ABS systems (1 in the last month), reconstructs and examines tires (4 in the last month), and examines skid marks, sometimes teaching about those subjects. I've done oil plate documentation regarding tread contact, am aware of the physics at both the tire and vehicle levels, and know who to call when I see something new.
Simply discussing how much contact exists when leaned over, or about how hard tread compounds may be, does NOT tell the whole story. The fact is that car tires have been used and used successfully since the beginning of motorcycles. Model A Ford tires were used extensively in the 1930s and VW tires later, long before we got the specialized tires we now have. Some touring motorcycles such as Goldwings have car tires installed for long life and/or heavier load capability. Sidecar motorcycles with car tires occasionally get run without the hack and car tires are very common in long distance competition.
Just like any other tire design, car tires on motorcycles have strengths and weaknesses affecting each aspect of the design trade-offs. Any change in tire profile and construction does change handling which affects handling, even between types of motorcycle-specific tires such as a road racing V and a touring oval. Stark differences exist between the design and construction of motorcycle road racing tires and thick carcass off-road desert tires. Neither of those have been optimized to long distance use in the way that car tires have been.
Car tires on a motorcycle will result in an integrated vehicle which is different than the set of design trade-offs which the vehicle designers intended. Doing so can be dangerous. This means that the rider is a test pilot of a new set of vehicle characteristics unless he has information which the original designers did not have. To have this information, the owner must either approach opening the performance envelope gradually, like the initial tester of any new vehicle, or collect experience about the same model tire on the same vehicle in the same types of use from people who can relate their experience.
So with the intent of sharing information, rather than hype and argument, and recognizing that all modifications are the choice and potential risk of the individual doing so, this thread is re-opened.
Bob / Checkswrecks
EricV
Riding, farkling, riding...
2011 Site Supporter
2012 Site Supporter
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Re: Car tire?
I wrote much of this before the original thread was locked. I have edited it to hopefully provide a more calm response based upon my actual experience. CW, feel free to edit if you feel it necessary, you have carte blanche in that regard.
My personal background is as a machinist working in the hydraulic tool industry for 20+ years and a diverse group of other manufacturing disciplines. I have a pretty good amount of time/experience with quality control and inspection procedures involved in very close tolerance work. I'm used to looking for, and picking out failure points and flaws in a wide range of materials and processes.
I have a significant amount of direct experience with this topic. It's fine to have an opinion, but we all need to remain open minded enough to understand that we may be wrong and our opinion may be based on incorrect or a lack of information.
I am Darksider #1 on the FJR forum. I did all the R&D, background research, liability research, proof of concept testing, failure mode testing and analysis and rode over 70k miles on CTs mounted to a stock FJR wheel. I have cut apart CTs used for 37k miles to examine the side walls for damage or unusual wear, as well as similar CTs used in solo II auto cross, which are subjected to some very heavy side loads on cars, for comparative analysis. I have seen and heard just about every argument anyone ever came up with on the topic. So understand that I've been down this road before and not much will be new to me. The Darkside thread on the FJR forum is filled with diatribes and BS as well is solid information and a lot of opinions. It's the single longest and still ongoing thread on that entire forum, thousands of replies and over 200 pages long. Some of my most strident opponents from the earlier parts of that thread now run a CT on their FJRs and have for years at this point.
Yes, the topic is controversial. Yes, it looks odd and many people simply can't understand why anyone would do it. And Yes, it's certainly not for everyone! The simple answer is not as simple as people assume. Some do it for cost benefits. A typical car tire will last 3-6 times longer than a typical moto tire. That's a significant monetary savings. I originally started the research simply because the Avon Azaro tires I could consistently get 12k miles from the rear, stopped being produced in the size the FJR takes. I tried several other tires but could find no other tire that got consistently over 10k miles riding to the wear bars. My personal risk threshold on tire wear is to ride them to the wear bars, then change for a new tire. I know many people that push that envelope farther, but that is their choice and their risk threshold. For me, it came down to being able to ride more or spending gas money on tires and riding less.
Others wanted a tire that could last for long trips or long endurance rally events. Some of the long endurance rallies last 10 and 11 days and historically riders have covered as much as 15k miles during the event. Riders with trips to Alaska, thru the Yukon often find it appealing to be able to mount one tire for the trip and not have to arrange a tire change while on the road, as well as having a tire than is more resistant to punctures or damage from rough and unimproved roads, not to mention road construction and poor road conditions. In both of these scenarios, the CT is a proven performer.
In regards to ABS systems, they are far more flexible than many people believe. On this forum, riders have changed their Super Teneres to 21" front wheels and 18" rear wheels, using wheels sourced from Woody's Wheel Works. The ABS and TCS both continue to work fine with the different sizes. Even with only a 21" front change. There are other issues with that kind of swap, but it suits some rider's needs. The CT presents no issue to how ABS works or wheel speed sensors and zero ABS faults have ever been reported on the FJR forum from CT users. I can personally tell you that the ABS continues to function just fine, as I routinely engage ABS during my riding to allow fluid to pass thru the valve block rather than stagnate there, which can cause, (and has), corrosion to build up on the piston that will seize it.
What most people fail to understand about using a CT on a motorcycle is how the CT carcass reacts to the leaning. People believe that you will roll over onto the side wall when cornering. This is not true. In fact, no motorcycle running a CT that is properly inflated has ever ridden on the side wall. Look at any CT mounted to a motorcycle and you will never see any indication of wear on the sidewall. Note also that you see cars with sidewall damage and rub wear far more often. The vast bulk of this is from rubbing curbs and extreme low pressure operation. In general, car owners are not as good about checking tire pressure as motorcycle owners, IMHO. Regardless, the side walls are still pretty tough on a CT!
What does actually happen with a CT mounted on a motorcycle is that as the rider leans, initially all of the tread stays on the ground and the carcass flexes, conforming to an oblong or elliptical shape at modest to moderate lean angles. When the lean angle exceeds the tire's ability to flex, several things simultaneously occur; The tire comes back to a round shape, and the rear of the bike lifts up. Now, this transition is important, because it's where many people believe there will be increased steering resistance. They believe this because of how it feels with a squared off motorcycle tire and incorrectly assume that it will feel the same way, only worse with a CT. This is not true. As you have previously mentioned, the tires are manufactured differently. A moto tire does not flex into an elliptical shape as it leans over.
When the CT lean exceeds the ability of the tire to flex with the inside sidewall effectively shorter than the outside, and transitions back to it's natural round shape, the outside edge of the tire does come off the pavement and the back of the bike lifts up. Note, that even at peg scraping levels of lean, there is nearly a third of the tire still in contact with the pavement, often more surface area than a moto tire's contact patch. This steepens the steering angle and quickens turn in, effectively canceling out any perceived resistance to turn in. There is no rider feel of a change, it just works together in harmony and the bike turns like normal during riding where counter steering dynamics are present. At sub ~10 mph where no counter steering dynamics are present, there is a different feel, but many, if not most people, find slow speed maneuvers to be even more predictable and stable with the CT. Different, but not beyond the rider's control.
Tire wear - Many people incorrectly assume that the CT when used on a motorcycle will wear on the sides as it corners. As I mentioned previously, because most of the tread stays on the ground, this does not happen except in extremely aggressive riding. 95% of the CTs I have examined on bikes, (hundreds), have even wear across the tire. This is another indication that the tire tread is seeing far more normal activity than people assume or expect. The CTs on bikes that I have seen with noticeable wear at the outsides of the tread are on bikes that have aggressive owners that use a lot of throttle coming out of curves. These are riders that typically wear out a motorcycle tire, that would last others 6-10k miles, in 3-4k miles. They go thru any tire faster than the average rider. That remains true with the CT, but again, they are still getting 3X or more tread life with the CT, as compared to the moto tires they would otherwise use. As one such rider told me, "I can still afford to be a hooligan and ride the way I want to ride, it just costs less with the CT."
Think about the cornering forces for car tires used on cars. They begin to roll over as cornering forces increase. If the tire pressure is too low, they can and do roll over onto the sidewall. Go to any autocross event and you will see people marking their sidewalls to check for sufficient pressure and using infrared temp measuring tools to check tire temperatures. I have used temperature testing as well to determine optimal tire pressures for moto use. Not unsurprisingly, they are in the range you would expect for a light sports car using the same tire. Most often in the 29-32 psi range.
In bike use, the CT does not roll over onto the sidewall. But because of the lean, it flexes the sidewalls differently. Interestingly enough, after 30-40k miles of moto use, interior inspections show no breaking down of the sidewall or damage unless the tire has been run in extreme low or zero pressure events.
So hey, what about that zero pressure event? We have all gotten flats on motorcycles. Well, nearly all, some people are luckier than others!
I've sure had my share of motorcycle flats over the years. The stronger sidewalls and construction of the CT, along with the way it fits on the motorcycle wheel, (very securely. In fact it's nearly impossible to rotate a freshly mounted CT on the wheel before it's aired up. Once it's on, it's on tighter than a moto tire due to the extra stiff side walls and heavier beads. This is with non-run flat tires. Run flat tires are even more secure.) Running a CT that is flat, on a motorcycle, will still damage the tire!! Having an event where you are stuck and have to ride on the flat tire to get to a safe place or to get to a place to replace the tire is no different than with a car. In more ways than one. If this happens on a car, you can safely, but slowly, drive to a safe position and the tire won't come off the rim unless it's badly damaged or this is done at higher speeds or for an excessive period of time. For the motorcycle that is equipped with a CT, you can safely ride on it, (at slower and prudent speeds), with no danger of it coming off. You can't do that with a motorcycle tire. ::005::
The next logical question is can you feel a difference when the CT is flat? A natural concern is that with the stronger and heavier CT, that perhaps a rider won't notice when the pressure gets low or is lost completely. The truth is, it feels just like a moto tire when this occurs. It will start to weave and act oddly in corners making the back end feel loose, just like a motorcycle tire.
Front tire wear - A CT on the back will make the poor handling characteristics of a worn front tire more exaggerated. While some people believe front tire wear is increased with CT use, I have not found this to be true. If you talk to a motorcycle tire engineer/professional about front tire wear, specifically cupping, they will explain that tire cupping on the front is typically caused by braking into corners, especially downhill ones, and exaggerated by low tire pressure. Riders that have the habit of braking hard into corners will cup the front tire. Riders that do this with a CT on the rear will still do this, but the CT makes the handling feel even worse with the cupped front tire. I do not believe the CT has anything to do with the front tire wearing or cupping faster, just that it's more noticeable in the feedback to the rider because of the CT.
Tire weight - Yes, the average CT is heavier than the average moto tire. Usually by about 10 lbs. This is unsprung weight and every suspension guru will tell you that's the worst kind. True! The added weight of the CT makes the suspension work a little harder. If your rear shock is tired, but your bike handles "fine" with the moto tire, slapping on the heavier CT will make it much more obvious that your shock is worn. However, it does not appear to actually wear the shock any faster with the heavier CT. I ran a Wilbers shock with hydraulic pre-load and a custom spring for my bike set up on my FJR. I didn't need to get rebuilds any sooner with the CT than I did before, with a moto tire. I do know of people that put a CT on a FJR with a tired shock and immediately realized the shock was toast. A new shock and all is well. Truth is, they needed the new shock anyway, but with the lighter moto tire were able to fool themselves into believing it was still ok. I'm talking about shocks with over 50k miles on them.
There is quite a bit more that can be said on this topic. I have little doubt [snip of mentioning specific member - CW] others will post contrary beliefs and opinions. But remember, I have actually done the work, the testing and the analysis on this topic. I'm not repeating second hand info told to me by someone that hasn't actually don't the work. If anyone wants to read more, there is a FAQ here: http://www.fjrforum.com/forum/index.php?showtopic=124275 It may be necessary to have an account and sign in to access that area of the forum.
The full thread on Darksiding is here: http://www.fjrforum.com/forum//index.php/topic/141913-going-to-the-dark-side/ Fair warning, it has over 4000 replies and over 150,000 views and is full of useless BS as well as really good questions and answers.
As a final comment, I have never proposed running a car tire on a Super Tenere or other bike with a wheel narrower than the CT manufacturers spec it for. Yes, some people are doing that. It exceeds my personal risk threshold to do so. I have not done any research or testing of CTs on the Super Tenere and do not advocate the use of a CT on a Super Tenere. At least one person is doing it, but on a sidecar equipped bike, (hacked). I don't know what size or type of tire they are using. As I understand, the shop that hacked their Super Ten installed that prior to them receiving the bike back in sidecar form.
I wrote much of this before the original thread was locked. I have edited it to hopefully provide a more calm response based upon my actual experience. CW, feel free to edit if you feel it necessary, you have carte blanche in that regard.
My personal background is as a machinist working in the hydraulic tool industry for 20+ years and a diverse group of other manufacturing disciplines. I have a pretty good amount of time/experience with quality control and inspection procedures involved in very close tolerance work. I'm used to looking for, and picking out failure points and flaws in a wide range of materials and processes.
I have a significant amount of direct experience with this topic. It's fine to have an opinion, but we all need to remain open minded enough to understand that we may be wrong and our opinion may be based on incorrect or a lack of information.
I am Darksider #1 on the FJR forum. I did all the R&D, background research, liability research, proof of concept testing, failure mode testing and analysis and rode over 70k miles on CTs mounted to a stock FJR wheel. I have cut apart CTs used for 37k miles to examine the side walls for damage or unusual wear, as well as similar CTs used in solo II auto cross, which are subjected to some very heavy side loads on cars, for comparative analysis. I have seen and heard just about every argument anyone ever came up with on the topic. So understand that I've been down this road before and not much will be new to me. The Darkside thread on the FJR forum is filled with diatribes and BS as well is solid information and a lot of opinions. It's the single longest and still ongoing thread on that entire forum, thousands of replies and over 200 pages long. Some of my most strident opponents from the earlier parts of that thread now run a CT on their FJRs and have for years at this point.
Yes, the topic is controversial. Yes, it looks odd and many people simply can't understand why anyone would do it. And Yes, it's certainly not for everyone! The simple answer is not as simple as people assume. Some do it for cost benefits. A typical car tire will last 3-6 times longer than a typical moto tire. That's a significant monetary savings. I originally started the research simply because the Avon Azaro tires I could consistently get 12k miles from the rear, stopped being produced in the size the FJR takes. I tried several other tires but could find no other tire that got consistently over 10k miles riding to the wear bars. My personal risk threshold on tire wear is to ride them to the wear bars, then change for a new tire. I know many people that push that envelope farther, but that is their choice and their risk threshold. For me, it came down to being able to ride more or spending gas money on tires and riding less.
Others wanted a tire that could last for long trips or long endurance rally events. Some of the long endurance rallies last 10 and 11 days and historically riders have covered as much as 15k miles during the event. Riders with trips to Alaska, thru the Yukon often find it appealing to be able to mount one tire for the trip and not have to arrange a tire change while on the road, as well as having a tire than is more resistant to punctures or damage from rough and unimproved roads, not to mention road construction and poor road conditions. In both of these scenarios, the CT is a proven performer.
In regards to ABS systems, they are far more flexible than many people believe. On this forum, riders have changed their Super Teneres to 21" front wheels and 18" rear wheels, using wheels sourced from Woody's Wheel Works. The ABS and TCS both continue to work fine with the different sizes. Even with only a 21" front change. There are other issues with that kind of swap, but it suits some rider's needs. The CT presents no issue to how ABS works or wheel speed sensors and zero ABS faults have ever been reported on the FJR forum from CT users. I can personally tell you that the ABS continues to function just fine, as I routinely engage ABS during my riding to allow fluid to pass thru the valve block rather than stagnate there, which can cause, (and has), corrosion to build up on the piston that will seize it.
What most people fail to understand about using a CT on a motorcycle is how the CT carcass reacts to the leaning. People believe that you will roll over onto the side wall when cornering. This is not true. In fact, no motorcycle running a CT that is properly inflated has ever ridden on the side wall. Look at any CT mounted to a motorcycle and you will never see any indication of wear on the sidewall. Note also that you see cars with sidewall damage and rub wear far more often. The vast bulk of this is from rubbing curbs and extreme low pressure operation. In general, car owners are not as good about checking tire pressure as motorcycle owners, IMHO. Regardless, the side walls are still pretty tough on a CT!
What does actually happen with a CT mounted on a motorcycle is that as the rider leans, initially all of the tread stays on the ground and the carcass flexes, conforming to an oblong or elliptical shape at modest to moderate lean angles. When the lean angle exceeds the tire's ability to flex, several things simultaneously occur; The tire comes back to a round shape, and the rear of the bike lifts up. Now, this transition is important, because it's where many people believe there will be increased steering resistance. They believe this because of how it feels with a squared off motorcycle tire and incorrectly assume that it will feel the same way, only worse with a CT. This is not true. As you have previously mentioned, the tires are manufactured differently. A moto tire does not flex into an elliptical shape as it leans over.
When the CT lean exceeds the ability of the tire to flex with the inside sidewall effectively shorter than the outside, and transitions back to it's natural round shape, the outside edge of the tire does come off the pavement and the back of the bike lifts up. Note, that even at peg scraping levels of lean, there is nearly a third of the tire still in contact with the pavement, often more surface area than a moto tire's contact patch. This steepens the steering angle and quickens turn in, effectively canceling out any perceived resistance to turn in. There is no rider feel of a change, it just works together in harmony and the bike turns like normal during riding where counter steering dynamics are present. At sub ~10 mph where no counter steering dynamics are present, there is a different feel, but many, if not most people, find slow speed maneuvers to be even more predictable and stable with the CT. Different, but not beyond the rider's control.
Tire wear - Many people incorrectly assume that the CT when used on a motorcycle will wear on the sides as it corners. As I mentioned previously, because most of the tread stays on the ground, this does not happen except in extremely aggressive riding. 95% of the CTs I have examined on bikes, (hundreds), have even wear across the tire. This is another indication that the tire tread is seeing far more normal activity than people assume or expect. The CTs on bikes that I have seen with noticeable wear at the outsides of the tread are on bikes that have aggressive owners that use a lot of throttle coming out of curves. These are riders that typically wear out a motorcycle tire, that would last others 6-10k miles, in 3-4k miles. They go thru any tire faster than the average rider. That remains true with the CT, but again, they are still getting 3X or more tread life with the CT, as compared to the moto tires they would otherwise use. As one such rider told me, "I can still afford to be a hooligan and ride the way I want to ride, it just costs less with the CT."
Think about the cornering forces for car tires used on cars. They begin to roll over as cornering forces increase. If the tire pressure is too low, they can and do roll over onto the sidewall. Go to any autocross event and you will see people marking their sidewalls to check for sufficient pressure and using infrared temp measuring tools to check tire temperatures. I have used temperature testing as well to determine optimal tire pressures for moto use. Not unsurprisingly, they are in the range you would expect for a light sports car using the same tire. Most often in the 29-32 psi range.
In bike use, the CT does not roll over onto the sidewall. But because of the lean, it flexes the sidewalls differently. Interestingly enough, after 30-40k miles of moto use, interior inspections show no breaking down of the sidewall or damage unless the tire has been run in extreme low or zero pressure events.
So hey, what about that zero pressure event? We have all gotten flats on motorcycles. Well, nearly all, some people are luckier than others!
I've sure had my share of motorcycle flats over the years. The stronger sidewalls and construction of the CT, along with the way it fits on the motorcycle wheel, (very securely. In fact it's nearly impossible to rotate a freshly mounted CT on the wheel before it's aired up. Once it's on, it's on tighter than a moto tire due to the extra stiff side walls and heavier beads. This is with non-run flat tires. Run flat tires are even more secure.) Running a CT that is flat, on a motorcycle, will still damage the tire!! Having an event where you are stuck and have to ride on the flat tire to get to a safe place or to get to a place to replace the tire is no different than with a car. In more ways than one. If this happens on a car, you can safely, but slowly, drive to a safe position and the tire won't come off the rim unless it's badly damaged or this is done at higher speeds or for an excessive period of time. For the motorcycle that is equipped with a CT, you can safely ride on it, (at slower and prudent speeds), with no danger of it coming off. You can't do that with a motorcycle tire. ::005:: The next logical question is can you feel a difference when the CT is flat? A natural concern is that with the stronger and heavier CT, that perhaps a rider won't notice when the pressure gets low or is lost completely. The truth is, it feels just like a moto tire when this occurs. It will start to weave and act oddly in corners making the back end feel loose, just like a motorcycle tire.
Front tire wear - A CT on the back will make the poor handling characteristics of a worn front tire more exaggerated. While some people believe front tire wear is increased with CT use, I have not found this to be true. If you talk to a motorcycle tire engineer/professional about front tire wear, specifically cupping, they will explain that tire cupping on the front is typically caused by braking into corners, especially downhill ones, and exaggerated by low tire pressure. Riders that have the habit of braking hard into corners will cup the front tire. Riders that do this with a CT on the rear will still do this, but the CT makes the handling feel even worse with the cupped front tire. I do not believe the CT has anything to do with the front tire wearing or cupping faster, just that it's more noticeable in the feedback to the rider because of the CT.
Tire weight - Yes, the average CT is heavier than the average moto tire. Usually by about 10 lbs. This is unsprung weight and every suspension guru will tell you that's the worst kind. True! The added weight of the CT makes the suspension work a little harder. If your rear shock is tired, but your bike handles "fine" with the moto tire, slapping on the heavier CT will make it much more obvious that your shock is worn. However, it does not appear to actually wear the shock any faster with the heavier CT. I ran a Wilbers shock with hydraulic pre-load and a custom spring for my bike set up on my FJR. I didn't need to get rebuilds any sooner with the CT than I did before, with a moto tire. I do know of people that put a CT on a FJR with a tired shock and immediately realized the shock was toast. A new shock and all is well. Truth is, they needed the new shock anyway, but with the lighter moto tire were able to fool themselves into believing it was still ok. I'm talking about shocks with over 50k miles on them.
There is quite a bit more that can be said on this topic. I have little doubt [snip of mentioning specific member - CW] others will post contrary beliefs and opinions. But remember, I have actually done the work, the testing and the analysis on this topic. I'm not repeating second hand info told to me by someone that hasn't actually don't the work. If anyone wants to read more, there is a FAQ here: http://www.fjrforum.com/forum/index.php?showtopic=124275 It may be necessary to have an account and sign in to access that area of the forum.
The full thread on Darksiding is here: http://www.fjrforum.com/forum//index.php/topic/141913-going-to-the-dark-side/ Fair warning, it has over 4000 replies and over 150,000 views and is full of useless BS as well as really good questions and answers.
As a final comment, I have never proposed running a car tire on a Super Tenere or other bike with a wheel narrower than the CT manufacturers spec it for. Yes, some people are doing that. It exceeds my personal risk threshold to do so. I have not done any research or testing of CTs on the Super Tenere and do not advocate the use of a CT on a Super Tenere. At least one person is doing it, but on a sidecar equipped bike, (hacked). I don't know what size or type of tire they are using. As I understand, the shop that hacked their Super Ten installed that prior to them receiving the bike back in sidecar form.
shrekonwheels
New Member
Re: Car tire?
???
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Re: Car tire?
Wow... that's a lot of Darkside to digest. 10 extra pounds is pretty significant, too.
I am CT curious but other than a couple spare tire cheapos and the one on Eliza's hack, I've yet to find a decent CT for the Tenere. Something with an aggressive, offroad tread. A hybrid trials/knobby tire would be ideal if they could get the durability and traction balanced. Kenda and Motoz make them for 18" dirtbike applications.
Wow... that's a lot of Darkside to digest. 10 extra pounds is pretty significant, too.
I am CT curious but other than a couple spare tire cheapos and the one on Eliza's hack, I've yet to find a decent CT for the Tenere. Something with an aggressive, offroad tread. A hybrid trials/knobby tire would be ideal if they could get the durability and traction balanced. Kenda and Motoz make them for 18" dirtbike applications.
Andylaser
Member
Re: Car tire?
Would probably fail the "fit for purpose" and "compatibility with other tyres on the vehicle" requirements here.
I can also see insurance companies using it as an excuse to not pay out (or recover costs from the rider).
This is a good read.
http://trafficsafe.org/index.php/trafficsafe-investigates-riding-on-the-dark-side-1683/
Would probably fail the "fit for purpose" and "compatibility with other tyres on the vehicle" requirements here.
I can also see insurance companies using it as an excuse to not pay out (or recover costs from the rider).
This is a good read.
http://trafficsafe.org/index.php/trafficsafe-investigates-riding-on-the-dark-side-1683/
Don in Lodi
Well-Known Member
Founding Member
2012 Site Supporter
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2014 Site Supporter
Re: Car tire?
The write up leaves a bit to be desired. Strange, nobody seems to have done any sort of hands on study on this except those that are deeply into it already. Tyresafe sounded the sharpest then ruined it with 'in our opinion'. Every claim of ruin and damnation for using a ct in that write up have been disproved by those that are on the sharp edge and have been for years. When you get your entire country's set of law makers telling you No, it's probably best not to mess with it though.
I've been in the car tire industry for a couple decades now. No science or anything, but cars beat the ever loving crap out of their tires. An mc can't even come close to doing the damage that a car does.
The write up leaves a bit to be desired. Strange, nobody seems to have done any sort of hands on study on this except those that are deeply into it already. Tyresafe sounded the sharpest then ruined it with 'in our opinion'. Every claim of ruin and damnation for using a ct in that write up have been disproved by those that are on the sharp edge and have been for years. When you get your entire country's set of law makers telling you No, it's probably best not to mess with it though.
I've been in the car tire industry for a couple decades now. No science or anything, but cars beat the ever loving crap out of their tires. An mc can't even come close to doing the damage that a car does.
groundhog
New Member
Re: Car tire?
I see that my posts from this thread before it was taken off have been removed. Whatever happened to freedom of speech and the right to have an opinion ?? If you are going to re launch a thread with previous posts on it, then leave everything even if you don't agree or happen to like the way it has been written. I will re state my opinion anyway, which is that I have never heard anything so ridiculous as putting a car tyre on a motorcycle. For me it's forget about the so called science by self proclaimed 'experts' surely it's as simple as - bike tyres are made to go on bikes and car tyres on cars and there is a reason for that. That may or may not be correct and there may be some grey area between the darkside and the other side, but it happens to be my opinion !
For me this has gone past the tyre issue it's more about the right to have an opinion and to be able to state that opinion in a way you want to.
I see that my posts from this thread before it was taken off have been removed. Whatever happened to freedom of speech and the right to have an opinion ?? If you are going to re launch a thread with previous posts on it, then leave everything even if you don't agree or happen to like the way it has been written. I will re state my opinion anyway, which is that I have never heard anything so ridiculous as putting a car tyre on a motorcycle. For me it's forget about the so called science by self proclaimed 'experts' surely it's as simple as - bike tyres are made to go on bikes and car tyres on cars and there is a reason for that. That may or may not be correct and there may be some grey area between the darkside and the other side, but it happens to be my opinion !
For me this has gone past the tyre issue it's more about the right to have an opinion and to be able to state that opinion in a way you want to.
Dogdaze
Well-Known Member
Re: Car tire?
::021:: I'm in the same camp as you. Flat=car, round=m/c, simples.groundhog said:
EricV
Riding, farkling, riding...
2011 Site Supporter
2012 Site Supporter
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Re: Car tire?
Please see my previous post. Your opinion is noted, as is your lack of experience and data to back it up. I applaud you for sharing. What's your opinion on colonizing Mars? I imagine you have an equal amount of personal knowledge & experience with that topic. ???
Please see my previous post. Your opinion is noted, as is your lack of experience and data to back it up. I applaud you for sharing. What's your opinion on colonizing Mars? I imagine you have an equal amount of personal knowledge & experience with that topic. ???
Re: Car tire?
As shown in the links which Eric provided for the FJRForum threads, the topic is like politics, religion, and gun control in absolutely bringing out passion on both sides of the argument. We don't cut, snip, and moderate in this forum much, so it seems to really catch people's attention when we do. Clean-ups happen much more frequently in the ADV forum (and others), but they don't leave tracks the way I did - things just disappear.
As I mentioned to somebody else, go ahead and start a "I love/hate car tires and goat-cheese" thread over in the Debates area. This is the Tech and Modification area and people are seriously interested in what works or does not, so please keep this thread to the subject in a way that may help them.
To put some redeeming material into this post, I'll offer that a couple of years ago in one of the Goldwing forums was an extremely well researched and long post from one of their members who looked into using car tires. Long story short is that the difference in the design of a motorcycle rim with the car tire bead meant that there could at least theoretically be a less than optimum engagement. In the end he found no accident reports and acknowledged all the people who have been riding car tires, but decided not to go dark side himself. The reason the post in that thread was so great and maybe somebody could go find it is because he really got into basic concepts with lots of easy to follow graphics for the dynamics, photos of sectioned tires and rims, interviews, etc.
groundhog said:
As shown in the links which Eric provided for the FJRForum threads, the topic is like politics, religion, and gun control in absolutely bringing out passion on both sides of the argument. We don't cut, snip, and moderate in this forum much, so it seems to really catch people's attention when we do. Clean-ups happen much more frequently in the ADV forum (and others), but they don't leave tracks the way I did - things just disappear.
As I mentioned to somebody else, go ahead and start a "I love/hate car tires and goat-cheese" thread over in the Debates area. This is the Tech and Modification area and people are seriously interested in what works or does not, so please keep this thread to the subject in a way that may help them.
To put some redeeming material into this post, I'll offer that a couple of years ago in one of the Goldwing forums was an extremely well researched and long post from one of their members who looked into using car tires. Long story short is that the difference in the design of a motorcycle rim with the car tire bead meant that there could at least theoretically be a less than optimum engagement. In the end he found no accident reports and acknowledged all the people who have been riding car tires, but decided not to go dark side himself. The reason the post in that thread was so great and maybe somebody could go find it is because he really got into basic concepts with lots of easy to follow graphics for the dynamics, photos of sectioned tires and rims, interviews, etc.
Re: Car tire?
My .02 worth. As far as the 1800 Goldwing goes, there isn't a single MC tire maker out there that makes a quality tire for it. I went through several and Bridgestone was the best I could find. I was going to do a 50CC ride, which ends up being a 5000 mile ride by the time you get to either coast and back home. I decided to go with a car tire for the ride. I didn't want anything much wider than the stock tire so I went with a 175/60X16 Dunlop SP Wintersport 3D and it was very close to the stock size.
Riding down the highway I loved the tire. With the lower air pressure it had a very soft ride to it. Taking it around corners was a little bit of a learning curve. It took a little getting used to, but everything new does. Long story short, the car tire was not bad at all on the Goldwing. It took some getting used too and by the time I got back home it felt normal. Plus with over 5K miles on the tire, it didn't show any wear at all.
I can honestly say I like riding on a MC tire better, but the CT is not as bad as some think. Most people that are so set against one, never tried it.
The one thing that you should never do is mount a 15" car tire on a 15" MC wheel. 16 and 17 inch car and MC rims are almost exactly the same size. A 15' car rim is several thousands smaller than a 15" MC rim and it is pretty dangerous just to pop it out on the rim. We built several Choppers in the 70's and put 15" car tires on them and it was always a nail bitter to get the tire to pop out on the rim.
I've been selling and mounting MC tires for a living going on 43 years now, so I have had a little experience mounting just about every kind of tire on every kind of rim.
My .02 worth. As far as the 1800 Goldwing goes, there isn't a single MC tire maker out there that makes a quality tire for it. I went through several and Bridgestone was the best I could find. I was going to do a 50CC ride, which ends up being a 5000 mile ride by the time you get to either coast and back home. I decided to go with a car tire for the ride. I didn't want anything much wider than the stock tire so I went with a 175/60X16 Dunlop SP Wintersport 3D and it was very close to the stock size.
Riding down the highway I loved the tire. With the lower air pressure it had a very soft ride to it. Taking it around corners was a little bit of a learning curve. It took a little getting used to, but everything new does. Long story short, the car tire was not bad at all on the Goldwing. It took some getting used too and by the time I got back home it felt normal. Plus with over 5K miles on the tire, it didn't show any wear at all.
I can honestly say I like riding on a MC tire better, but the CT is not as bad as some think. Most people that are so set against one, never tried it.
The one thing that you should never do is mount a 15" car tire on a 15" MC wheel. 16 and 17 inch car and MC rims are almost exactly the same size. A 15' car rim is several thousands smaller than a 15" MC rim and it is pretty dangerous just to pop it out on the rim. We built several Choppers in the 70's and put 15" car tires on them and it was always a nail bitter to get the tire to pop out on the rim.
I've been selling and mounting MC tires for a living going on 43 years now, so I have had a little experience mounting just about every kind of tire on every kind of rim.
groundhog
New Member
Re: Car tire?
I assume your comments were aimed at me and I won't bother responding (or adding anything further to this thread) except to say my comments are my opinion right or wrong. And since you ask I reckon about 4.30 pm on Friday would be an ideal time to colonize Mars 8)EricV said:
Re: Car tire?
Yep, Morgan and they still make them with wooden chassis too. There are a few kit car manufacturers who use bike tyres on very period looking replicas, one of which uses a Guzzi engine and looks very 1930's.Don in Lodi said:
Re: Car tire?
For those who want to debate or post opinions, put it HERE in the Debates part of the forum:
http://www.yamahasupertenere.com/index.php?topic=16401.new#new
Folks, you can post all the stuff that has been deleted from this thread. Just do it there and leave this thread for actual experience.
You've been asked nicely.
The Debate thread has been set up for you.
For those who want to debate or post opinions, put it HERE in the Debates part of the forum:
http://www.yamahasupertenere.com/index.php?topic=16401.new#new
Folks, you can post all the stuff that has been deleted from this thread. Just do it there and leave this thread for actual experience.
You've been asked nicely.
The Debate thread has been set up for you.
RCinNC
Well-Known Member
Re: Car tire?
Hey, I got snipped!
I don't dispute the snipping, I'm just wondering what I said that was "snip-worthy". I try to avoid being a d-bag on the forums and keep things businesslike, so I'm surprised I violated my own rules.
Hey, I got snipped!
I don't dispute the snipping, I'm just wondering what I said that was "snip-worthy". I try to avoid being a d-bag on the forums and keep things businesslike, so I'm surprised I violated my own rules.