Suspension Sags

[avc8130]

Off-road: No heavy duty off-road. Off-road I slow down when it gets technical. Beginning to like hardpack gravel. The K60 is going to help my confidence in everything off-road.

KLR: Prefer a Continental TrailAttack. Very predictable.

Road: No reason to speed when it is straight and boring. Love twisties and will push them if the road is clean. Up and down twisties are even more fun. Have never scrubbed the chicken strips off any tire.

I'm a bit heavier than you and I like my .95s. My off road is similar. Graded gravel/dirt. I do like to push it on the street. The stock springs are ~.85 in the initial rate. .90s might work for you. I believe Firefight runs .95s.

ac

 

[tomatocity]

I'm a bit heavier than you and I like my .95s. My off road is similar. Graded gravel/dirt. I do like to push it on the street. The stock springs are ~.85 in the initial rate. .90s might work for you. I believe Firefight runs .95s.

ac

Phil is local to me. He is the rider that adjusted my stock suspension. Phil can be REALLY fast in all conditions. Are you getting your springs where he does or another vendor?

 

[avc8130]

Phil is local to me. He is the rider that adjusted my stock suspension. Phil can be REALLY fast in all conditions. Are you getting your springs where he does or another vendor?

I got my springs from my local suspension tuner: Stoltec Moto.

ac

 

[tomatocity]

I got my springs from my local suspension tuner: Stoltec Moto.

ac

Is it a full length spring or do you have to use a longer spacer?

 

[avc8130]

Is it a full length spring or do you have to use a longer spacer?

Full length.

ac

 

[Rasher]

How aggressive is the progression :question:

My understanding is they do not switch at a certain point, but rather progressively stiffen as they compress - which sounds ideal for a bike with many uses solo / two up / road / dirt / commuting / touring / chasing power rangers.

For those not sure of the technicalities:-

http://www.moto-racing.co.uk/Guides/LinearVsProgressive.html

Just from the pictures here:-

http://www.yamahasupertenere.com/index.php?topic=2811.0

The Yamaha one looks to have a very slow rate as the majority of the spring is the wider spaced coils, so I would assume the rate very slowly increases, with the first 50% probably being pretty soft.

I would certainly like to have the spring stiffer to start, but wonder if a different progressive spring may work well, with the Yamaha being 0.85 - 1.16 maybe starting and ending a bit stiffer than OE (i.e. start at 0.9 and ending at 1.2) or even starting quite bit stiffer but ending a bit softer (maybe 0.95 initial rate but just 1.05 final rate)

On the other hand these bikes have so much travel compared to road bikes even with a linear spring I would hope it could be soft enough to give a good ride, yet still not bottom out, or at least not with my predominantly road and no more than gentle off-road use (Unpaved roads and easy tracks / trails) with only about 20% of the OE spring being the tighter winding I am guessing a 0.95 linear would probably take as much force to bottom, if not more, anyone clever enough to work this out :question:

 

[avc8130]

The stock Yamaha spring is considered a "dual rate", not a progressive.

In other words, it is ~.85 until the spring is compressed the portion of travel that spring has and then it is ~1.2.

ac

 

[dcstrom]

So last weekend I did a dry run with my bike fully load in prep for my RTW trip. Load comes to 170lbs at the moment, including the weight of all the containers (jesse bags, Bags-Connection tankbag, H&B topbox, Ortlieb medium. Weight also included 5 liters of water and 1.5 gallons of fuel. So not too bad I think... I will probably gain another 10lb by the time I'm finished, a few small things to add.

Anyway, after a couple of beers at a mates place (hold my beer and watch this!), and with said mates to help should I fail, I decided it would be a good time to see if I could pick it up. Laid it down on the grass then tried to lift it the "correct" way, by backing into the seat and lifting with my legs. No go... with the bike on the left side, me facing away from it with my bum on the seat, I had nowhere to get a grip with my left hand. This is with Jesses on - I could easily grip the racks with the bags off, but no way to get a bag off with the bike on its side.

Eventually I just did a brute force thing - facing the bike, squat really low, grip the crash bar with the left hand, right just bracing on the seat cos there's still nowhere to get a good grip, and shoulder into the curve of the tank. This is where I got most of the lift. Then push like buggery using my legs. Came up pretty easy, no back strain either. (it doesn't look right in the pic, but I think this was taken before the actual lift).

Next time I'm going to try attaching a strap to the pillion hanger, and use that to grab onto for the butt-in-seat technique.

Part of the point of this exercise was to have people help me set up sag. I soon realised that trusting myself or anyone else to be accurate with numbers after a few beers was pure folly! However I did get to do a few miles with this setup and it felt fine - plush even... nicer than when unloaded. This was with settings close to stock, and rear preload on the soft side of the middle.

I did some smooth dirt roads, all good there too. Given that I have some room to play with preload, I'm thinking the stock suspension will probably work fine. Will see after 10,000 miles around the US - if I need to upgrade I should know by then!

 

[adkbeemer]

....did not intend to poop and run here. Nice back and forth on the stock setup. It is very much about what you define as your "ride" that determines your perspective on the stock set up. I'm sure that running at either edges of the design envelope (super road warrior or mega offroad hound) will really show the advantages of a better shock. Experimenting so far two up I really like the rear - more and more I'm looking forward to our first long two up trip in three weeks.

The K60s arrived Friday and I'll drop them on after a one up trip to Maine later this month. I'm excited about them as well.

I agree that the front springs have the same issues as my Wee strom did and that will be a great first "cheap" ;D upgrade this winter while the bike sits idle.

dcstrom I look forward to hearing more about your RTW trip as things progress - how lucky you are! ::012:: Best of luck to you on your adventure!

 

[Firefight911]

How aggressive is the progression :question:

I would certainly like to have the spring stiffer to start, but wonder if a different progressive spring may work well, with the Yamaha being 0.85 - 1.16 maybe starting and ending a bit stiffer than OE (i.e. start at 0.9 and ending at 1.2) or even starting quite bit stiffer but ending a bit softer (maybe 0.95 initial rate but just 1.05 final rate)

On the other hand these bikes have so much travel compared to road bikes even with a linear spring I would hope it could be soft enough to give a good ride, yet still not bottom out, or at least not with my predominantly road and no more than gentle off-road use (Unpaved roads and easy tracks / trails) with only about 20% of the OE spring being the tighter winding I am guessing a 0.95 linear would probably take as much force to bottom, if not more, anyone clever enough to work this out :question:

Rasher,

In discussing the spring rate of the forks, etc. it is important to understand the the spring rate of the forks is not solely based on the spring itself. It is also impacted greatly by air gap. This is, of course, determined by fork oil height. An independent function from oil weight. The oil merely determines the amount of air available during compression. The rate of air as a spring is exponential but comes in to play greatly as you near the end of the fork travel under compression.

More air gap (lower fork oil height) will need a higher coil spring rate to hold up the bike possibly to prevent the fork from collapsing under compression and will allow tuning of the feel of the front end in conjunction with the oil weight.

Methodical adjustment of what you have and good note taking will allow you to get what you are after.

You just have to start very honestly with what you are after and what you are intending the use for and where it is important for you for the suspension to be at it's optimum and where more compromise is acceptable.


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[Rasher]

I have spoken to MCT and they reckon they can do a good job with the stock springs, they have suggested a strip of the forks to have a look, relace the OE sludge for decent quaility suspension fluid.

They seem to think with the correct oil / air gap / settings it will be much better and the issue I have (excessive dive) is likely to be more related to damping than springing.

I have to call them next week to book in, but they have a six week waiting list so won't be getting it done until late August, will have rar shock fitted at same time.

 

[avc8130]

"OE Sludge"

LOL

The stock Yamaha fork oil is probably some of the lightest available.

ac