brake pads

TomZ

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In 90K miles on two STs (a 2012 and a 2015) I've gone through 4 sets of EBC HH rear pads and 2 rotors. Rear brakes seem to wear quickly for me on the ST, but the fronts have never worn out. With the HH sintered pads, the rotors show grooving and develop a wear lip after just a few K miles. Unlike the fronts, the rear caliper on the ST does not completely relax with the brakes not applied, and the pads drag a little. This seems worse with the HH pads because the sintered pad material is fairly porous and tends to pull out in spots, leaving abrasive material between the pads and rotor. To reduce the drag, I occasionally take off the caliper, clean it and re-lube the guides and piston.

Both rotor replacements resulted from wearing completely through a brake pad without realizing it and damaging the rotor. Fortunately the OEM rotors are not very expensive and are easy to replace. When I first rode the Tenere I used the rear brake excessively and also experimented with trail braking. Now I use mostly engine braking.

The latest failure occurred after riding steep unpaved roads where I was using the rear brake a lot. As the attached pictures show, the right-side pad has been bent by the piston and almost completely worn through. Most of the left pad is still intact but lot of the sintered material has fallen out. The stainless steel brake piston was also discolored by heating and the outer seal on the caliper was badly deteriorated. Also, the right side of the rotor was glazed and heavily scored. I'm not sure how all this happened, but possibly dirt jammed the caliper guides and prevented the right side pad from sliding.

I installed new OEM caliper seals with the grease that came with them, new piston, guides and heat shields. The rotor still useable and cleaned up with wet-or-dry sandpaper. I also installed OEM brake pads and intend to do so in future because I don't like the way the HH sintered pads lose material. With the OEM pads, the rotor wear is now smooth as it should be.
 

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Checkswrecks

Ungenear to broked stuff
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The rear pads do wear faster on the Tenere and the rotor is known to groove, while the fronts go on forever.
 

Sierra1

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This isn't a brake PAD question, :):002::), but a brake LINE question. I am surprised that nobody seems to change their rubber lines for braided lines. I use them on my 'ol FJ, and can feel the difference. I did locate a comment here that claims that ABS nullifies the braided line advantage. I don't understand that. ABS doesn't effect braking input; until there's too much input. Has anybody made the switch? And if so, could you feel a difference?
 

Commuter Boy

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Halifax NS
I replaced the rear pads early on my 2015: at 25,000 km they were down to a quarter of their thickness of the replacement set.

That being said, I've kept the old pads with a bit of meat on them, just in case the replacements wear down quickly, I'll have something to swap in before I start grinding the rotors down.
 

EricV

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RCinNC said:
Yep, that sure sums a lot up. ::008::
I'll concede that an engineer's opinion holds more weight than mine, because I'm not an engineer.
Not so fast there. I'd be more likely to listen to your experience with actual use than the theoretical ramblings of an engineer that's never actually used the products he/she designed on CAD and spec'd based on a bean counter's cost graphs as well as what was simply on hand and in use from current vendors the company was using.

All OEMs use outside vendors. Yamaha doesn't make brake rotors from scratch, they buy them from a vendor. Perhaps, several vendors. Smart OEMs have at least one back up vendor for outside items so if demand is high or a problem develops with one vendor, production doesn't come to a halt.

As a machinist that worked for a big OEM, I can't tell you how many times I had to teach the laws of physics to an engineer. And thermodynamics. And fluid dynamics. A degree doesn't mean knowledge in the field. It means you went to school and spent a whole lot of time learning what things are called. Zero real experience working with real materials and solutions until you get a job and spend some time really doing it. And seeing your failures, and hopefully learning from those to do a better job.

@hobdayd - Don't get too worked up. You have every right to your opinion based on your experience. But you are forgetting that your OEM needs are based on the OEM's parameters, not real world, not individual performance needs or preferences. Brakes are a critical function item. You bet. It's a metal disk with to organic or synthetic pads squeezing it. It's not rocket science, and rocket science isn't really all that hard either. ::) It's just math.

At the end of the day, most braking systems are spec'd by OEMs to work well, not dust too much, and provide average braking performance under all conditions. Not lose function when wet, not melt rotors when excessively used, not boil fluid, etc. No OEM can guess exactly what conditions each individual product user will encounter. End users get options to meet their individual needs. Some will accept higher rotor wear for better perceived stopping performance. Others want low dust and are fine with performance that stops the bike under their 'normal' conditions.

I'd be willing to bet that no combination of rotors and pads currently sold on the market today will cause outright failure of a brake system when the user applies the brakes in an on road situation. Toss in neglect, loose parts, track use and corrosion and all bets are off. ;D

So yes, do what you want. The bike will still stop. ::002::
 

TNRyder

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Ever soggy ☀️ state
EricV said:
Yep, that sure sums a lot up. ::008::
Not so fast there. I'd be more likely to listen to your experience with actual use than the theoretical ramblings of an engineer that's never actually used the products he/she designed on CAD and spec'd based on a bean counter's cost graphs as well as what was simply on hand and in use from current vendors the company was using.

All OEMs use outside vendors. Yamaha doesn't make brake rotors from scratch, they buy them from a vendor. Perhaps, several vendors. Smart OEMs have at least one back up vendor for outside items so if demand is high or a problem develops with one vendor, production doesn't come to a halt.

As a machinist that worked for a big OEM, I can't tell you how many times I had to teach the laws of physics to an engineer. And thermodynamics. And fluid dynamics. A degree doesn't mean knowledge in the field. It means you went to school and spent a whole lot of time learning what things are called. Zero real experience working with real materials and solutions until you get a job and spend some time really doing it. And seeing your failures, and hopefully learning from those to do a better job.

@hobdayd - Don't get too worked up. You have every right to your opinion based on your experience. But you are forgetting that your OEM needs are based on the OEM's parameters, not real world, not individual performance needs or preferences. Brakes are a critical function item. You bet. It's a metal disk with to organic or synthetic pads squeezing it. It's not rocket science, and rocket science isn't really all that hard either. ::) It's just math.

At the end of the day, most braking systems are spec'd by OEMs to work well, not dust too much, and provide average braking performance under all conditions. Not lose function when wet, not melt rotors when excessively used, not boil fluid, etc. No OEM can guess exactly what conditions each individual product user will encounter. End users get options to meet their individual needs. Some will accept higher rotor wear for better perceived stopping performance. Others want low dust and are fine with performance that stops the bike under their 'normal' conditions.

I'd be willing to bet that no combination of rotors and pads currently sold on the market today will cause outright failure of a brake system when the user applies the brakes in an on road situation. Toss in neglect, loose parts, track use and corrosion and all bets are off. ;D

So yes, do what you want. The bike will still stop. ::002::
Well stated Eric.


Sent from my iPhone using Tapatalk
 

EricV

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Sierra1 said:
This isn't a brake PAD question, :):002::), but a brake LINE question. I am surprised that nobody seems to change their rubber lines for braided lines. I use them on my 'ol FJ, and can feel the difference. I did locate a comment here that claims that ABS nullifies the braided line advantage. I don't understand that. ABS doesn't effect braking input; until there's too much input. Has anybody made the switch? And if so, could you feel a difference?
The reason ABS negates much of the improvement, (firming up the feel of the brake lever and allowing better modulation), is because of the solenoid in the ABS pump. In very simple terms, there is a reservoir of fluid that has a spring loaded piston there. Sensors at the wheels trigger the ECU program to cycle the piston to avoid wheel lock up. This only works with the brakes are applied to a pressure beyond what would cause wheel lock up. Another issue is ABS systems simply have a lot more line in them and if you're not changing all the rubber lines to steel or s/s braid, there will still be a rubber line to expand under pressure.

Because there is always a reservoir of fluid in the ABS block and it's spring loaded by the solenoid, the brake system can never be as firm as a non-ABS system with braided lines. What you're improving with s/s braided lines is the elimination of the rubber line expanding under the hydraulic pressure of the master cylinder, as applied by the brake lever or pedal. That's what makes the system feel soft, the give in the rubber lines. Also why air in the system makes it feel 'soft'. Air compresses, hydraulic fluid, (brake fluid, etc), does not compress.

I know of several ABS bikes that riders I personally know have changed to all steel and s/s braided lines. There is an improvement, but it's nothing like a non'ABS bike'
s rock hard brake lever feel and precise ability to modulate the brakes at the edge of lock up. Of course, ABS when used correctly, mimics that modulation better than most riders can manage in crisis conditions. And that's when we need it most. I wouldn't choose ABS for a track bike. But I love it on street bikes. I've practiced threshold braking, a lot. If I hadn't learned that process, I'd probably still prefer ABS on the track too, it would simply mean a different braking process for me.

I hope that offers a small amount of insight in answering your questions.
 
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