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Old 01-02-10, 09:41 PM   #1
dwhitlow
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Upgrading road bike brakes. Need more stopping power.

I have an '09 Fuji Roubaix with Tektro R350 brakes on it. I'm overall happy with the bike, but I'm not super happy with the brakes. I'm a big guy (~250), and the bike feels a little sketchy when going down hills. I'm not worried about the speed, but I'd love to know I can stop when I need to. I did replace the Tektro pads with Ultegra brake pads, but that didn't really make a big difference.

Does anyone have any recommendations on brakes for a guy my size that will noticeably increase stopping power? I have Tiagra brifters that I'm fine with. Should I just focus on the brakes/pads themselves, or do I have to focus on cables, etc. as well? I'd prefer not to replace rims at this point, but how big a difference would that make in the grand scheme of things as well?

Thanks in advance for any help/suggestions.
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Old 01-02-10, 09:55 PM   #2
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If your brake shoes have the sexy little holders get some Koolstop salmon coloured replacements. Or if not then STILL get the correct Koolstop salmon coloured replacements. I've tried lots of pads over the years but I have not found any that work as well or better. The salmon coloured pads provide more stopping force for the same effort across the spectrum.

PS: some may suggest different calipers. But check the suggestions out first for the dimensions. Brakes are all about the OVERALL system leverage and not any one part of the system. What you need to get a gain in the system leverage is a lever or a caliper that moves the pads less for a given movement at the lever. For example if your present setup moves the pads 1 mm for each mm of lever travel then you need a new lever or caliper that moves the pads 0.9 mm or even less per mm of lever travel to actually gain an appreciable difference in stopping power. If you can actually gain this increase in the leverage ratio THEN swapping to the caliper that provides it is an excellent mod. Pricey though. I'd start with the Koolstop salmon pads first. Even if you do go with a caliper swap you'll want to move the salmon pads over anyway.

Messing with changing the pads is a different situation. There you're swapping the existing pads for options that provide a higher coefficient of friction with the aluminium face of the rim.

This coefficient of friction issue is also one of the reasons why if you were to switch to ceramic coated rims that you would need to go with a ceramic specific pad to get the whole benifit out of the swap. This option is a "matched pair".

Last edited by BCRider; 01-02-10 at 10:02 PM.
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Old 01-02-10, 10:04 PM   #3
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Another vote for the Salmon Kool Stop. Changed my Cannondale's less than stellar brakes completely. Now, they compare with the V-brakes on my Hybrid!
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Old 01-02-10, 10:51 PM   #4
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Another vote for the Salmon Kool Stop. Changed my Cannondale's less than stellar brakes completely. Now, they compare with the V-brakes on my Hybrid!
I like the Kool-Stop salmon-color pads also, but I've had issues with them squealing on brand-new rims. Once the rims are worn down a little, switch to salmon- you won't regret it.
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Old 01-02-10, 10:51 PM   #5
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Another vote for the Salmon Kool Stop. Changed my Cannondale's less than stellar brakes completely. Now, they compare with the V-brakes on my Hybrid!
Grind the stupid plow tip off the dura compatible pads, don't forget.
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Old 01-02-10, 11:03 PM   #6
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The brakes that come on the Roubaix have a fair amount of flex in them, i.e. the harder you squeeze, the more they flex. So you hit a point of diminishing returns as you apply brake pressure. A better caliper will help. Lots of Ultegra 6600 brakes on ebay since the 6700's came out. It won't be a HUGE difference since you've already switched pads, but it will be better. --Ryan
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Old 01-03-10, 01:49 AM   #7
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From the late 1970's into the early 1980's: The Scott Mathauser - Scott Superbrakes. Made with the recipe from today's Kool Stop, and manufactured with Scott Mathauser. Still made today as Kool Stop Salmon. Note the beveled rectangular washers for toe-in:

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Old 01-03-10, 08:01 AM   #8
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After you've changed pads, another thing to check is the cabling. Make sure the housings are correctly sized and nicely cleaned up at the ends. Check the housings are installed so the housing ends are fully seated at the each stop. If the original assembly was not well done, this can yield quite an improvement in braking.
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Old 01-06-10, 11:38 PM   #9
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Your cables would have to be pretty crappy indeed to hurt braking, especially the front. Brakes are far more tolerant of cable dramas than indexed gears...

If better pads don't sort it, swap the front calliper for at least 105.
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Old 01-06-10, 11:58 PM   #10
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Your cables would have to be pretty crappy indeed to hurt braking, especially the front. Brakes are far more tolerant of cable dramas than indexed gears...
I disagree. I've had new bikes where the cable housing compressed enough that I was able to easily bottom out the brake levers even with the brakes properly adjusted and everything installed correctly. I insisted that the housing be switched out before accepting the bikes. Both times the mechanic was initially very skeptical that better housing would make a difference, but they changed their tune after checking the brakes when they put on the heavier-duty housing.
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Old 01-07-10, 03:10 AM   #11
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If the brakes 'bottom-out' regardless of who you set them up right - pitch 'em! Or take it to LBS. Try replacing the cable's first. No go? Major problem. LBS can check spring-tension and other things. If they are old brakes - chances are: Start Shopping.
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Old 01-07-10, 08:10 AM   #12
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Stupid question, but are you using BOTH brakes fully? Some people tend to rely on the rear brake, which only has about 30% of the braking power.
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Old 01-07-10, 09:51 AM   #13
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Originally Posted by dwhitlow View Post
I'm a big guy (~250), and the bike feels a little sketchy when going down hills. I'm not worried about the speed, but I'd love to know I can stop when I need to. I did replace the Tektro pads with Ultegra brake pads, but that didn't really make a big difference...
There's a practical limitation on braking power on a bike that has nothing to do with the brakes but rather with weight distribution. Brakes stop the bicycle's motion not the rider's. The rider's motion is stopped by holding onto the bike. This presents a problem. The braking force acting on the rider is trying to lift the bike's rear wheel. This is countered by the rider's weight. Braking deceleration must be less than (l/h)g to avoid lifting up the rear wheel on level pavement, where g is gravitational acceleration (21 mph/sec), l and h are the horizontal and vertical distances of the center of mass of the bike and rider with respect to the point of contact of the front wheel with the ground. For most practical geometries, this limits the maximum braking deceleration to 0.6 g or approximately 12 mph/sec. This corresponds to approximately 0.8g deceleration that may be applied by the wheels to dry pavement before they start skidding.

One can design a braking system that could produce any deceleration rate. However, weight distribution limits their effectiveness. All quality bicycle brakes meet this upper limit with minor variations. You're going to have to adjust your riding habits, if you want to have the security that you can stop on a dime while taking that downhill at 30+ mph.
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Old 01-07-10, 10:22 AM   #14
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I think it's already been said, but just to summarize succinctly,

1) make sure you are braking correctly. Primarily the front brake and all that
2) swap pads for Kool-Stop Salmon
3) re-do the cables, or have someone skilled do it for you. This does make a difference, and it's worth looking into, because cables are a lot cheaper than brakes.
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Old 01-07-10, 11:36 AM   #15
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While everyone's advice as been spot on, just recognize that road bikes go faster and have less rolling resistance then an MTB, hybrid, or comfort bike and do require more stopping distance.

Still, replace the pads with something better then the junk that came on them. My Motobecane Messenger has cheap caliper brakes that had junk brake pads. I replaced them with a set of Bontranger pads and the difference was very noticeable.
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Old 01-07-10, 12:45 PM   #16
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Make sure to "flip down" that brake release lever. Lots of folks forget to flip it down when taking off or putting back on the wheel.
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Old 01-07-10, 01:21 PM   #17
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Another thing to practice is to move back on the saddle on a fast downhill. Way back. If you do it well, your tummy will be on the saddle, and your tush will be way behind the saddle. This will prevent your rear wheel from lifting, which lets you apply more power to both brakes safely. Practice this at moderate speed and gradually increase the speed at which you practice it. I look like I'm lying down when I descend. It gives me a very sure feeling, too.

If you ever feel your rear wheel lifting or slipping, let up on the FRONT brake, because you are tossing too much weight forward.

I concur with Kool Stop brake pads. Some are as good, but there are none better.
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Old 01-07-10, 01:37 PM   #18
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Another +1 to what everyone has said about Kool Stop salmons, braking technique, etc. I doubt if there's anything wrong with the cables on a bike that new. I've got an '09 Fuji Roubaix here in the shop, I just checked the brakes. Those stock gray pads definitely should be changed for Kool Stops for optimimum braking. Otherwise, there's nothing inherently wrong with the stock brakes-
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Old 01-07-10, 07:09 PM   #19
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There's a practical limitation on braking power on a bike that has nothing to do with the brakes but rather with weight distribution. Brakes stop the bicycle's motion not the rider's. The rider's motion is stopped by holding onto the bike. This presents a problem. The braking force acting on the rider is trying to lift the bike's rear wheel. This is countered by the rider's weight. Braking deceleration must be less than (l/h)g to avoid lifting up the rear wheel on level pavement, where g is gravitational acceleration (21 mph/sec), l and h are the horizontal and vertical distances of the center of mass of the bike and rider with respect to the point of contact of the front wheel with the ground. For most practical geometries, this limits the maximum braking deceleration to 0.6 g or approximately 12 mph/sec. This corresponds to approximately 0.8g deceleration that may be applied by the wheels to dry pavement before they start skidding.

One can design a braking system that could produce any deceleration rate. However, weight distribution limits their effectiveness. All quality bicycle brakes meet this upper limit with minor variations. You're going to have to adjust your riding habits, if you want to have the security that you can stop on a dime while taking that downhill at 30+ mph.
very nice, gentle way of stating the obvious.

Last edited by illwafer; 01-07-10 at 10:04 PM.
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Old 01-07-10, 07:37 PM   #20
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very nice, gentle way of stating the obvious.
The limitations on a bike's maximum braking rate are obvious only if you know about them and realize why. A lot of riders don't.
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Old 01-07-10, 09:45 PM   #21
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Your cables would have to be pretty crappy indeed to hurt braking
I disagree. I've had new bikes where the cable housing compressed enough that I was able to easily bottom out the brake levers even with the brakes properly adjusted and everything installed correctly.
That much mush is pretty crappy indeed.
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Old 01-07-10, 10:42 PM   #22
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A lot of that explanation was not at all obvious to me.
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