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  1. #1
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    Braking Issues, bothering me very much, help please

    i just got a new pair of the stroker trails, 8", about 2 weeks ago. they are all burnished in by now, and when i slam on braking power, or lock the pads on, the tires hop and and stop really choppy on any terrain, dirt, forest floor, rock, and asphalt. its almost as they bounce, and do not have a clean skid, by just sliding. I can tell it is not good for my bike, as everything rattles and vibrates horrendously... anyway, it would be great if i could have some insight. Bob

  2. #2
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    Two suggestions

    -Bring your bike into a mechanic and watch him work on your brakes and you'll learn how to set them up properly. (And, you'll be a lot safer when your riding!)

    -Quit 'skidding' your rear tire. Use your front brake to control your speed and don't lock out and skid your rear tire. Your front brake has about 75% of your braking power, because your weight is behind your front wheel vs. your rear brake where your weight is in front of the rear wheel.

    Your rear brake is use to control your bike during slow speed technical maneuvers, and also to 'rest your front brakes during long descents and prevent over heating.

    Cheers,

    Kane

  3. #3
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    The rear brake also helps "tighten" a turn if you are going a little too fast.
    Not that all teenagers are evil mind, just most of them.

  4. #4
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    The problem may not be....

    your brakes. Using knobby tires? If so when you put large amounts of braking foce on the tire you are forcing the knobs to bite in hard. The knobs flex under this force, if you exceed their ability to maintain grip they basically skip or loose traction. Once this happens the knobs spring back to their normal shape and cause the tire to hop a little. Once the tire recontacts the trail it bites in hard again and the cycle repeats it self creating a shudder and vibration. This can happen on a hardtail, ridged or full suspension bike, but is usually most noticeable and common on an FS bike. It's also more common with deeply lugged tires and/or tires that use softer rubber compounds for the tread blocks. Also running tubless setups at low pressures can contribute to the effect as well.

    The clue to this one is it only happens when you apply the brakes hard trying to lock up the wheel. You don't mention it happening at any other time. So it's likely not the brakes at all, but your tires and braking method. You shouldn't be locking up and skidding on the trail in the first place, and there really is no reason to lock up on pavement. You best braking performance comes just before lock up before the tire skids. Once you induce a skid the tire brakes traction with the surface and you actually start moving faster. The solution, don't try to lock em up! It's hard on the trail, hard on the tires, and as you've noted can be hard on other components as well.

    Good Dirt
    "I do whatever my Rice Cripsies tell me to!"

  5. #5
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    yo, squash, thats exactly what i was looking for. this brings me to another question, why didnt it happen with my el camino brakes just before (on the same bike/ tire set up), i do know that what you stated is completely true about the way the tire skips and shudders. Also, could it be solved by finding a better tire?

    thanks a bunch, Bob

  6. #6
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    Hmmm....

    possibly the stokers are just that much more powerfull than the camino's, hard to say for sure. I'm certain that the strokers are a more powerful brake. Also they should modulate quite differently than the caminos did.

    It's a good possiblity that a different tire would help. But one thing to do before you start searching for a different tire. Clean your rotors! A good rub down with rubbbing alcohol would be a good idea. Something as insignificant as finger prints on the braking surface can also set up this kind of thing. The shin oil from a finger print or two can create a slick spot on the rotor. The pad hits it and "slips" a little then grabs hard once past it. Usually this just gives a pulsing feeling to the brake. But if the grab after the spot is hard enough it would cause the tire react as I described in my previous post as well. Another possibility would be uneven burn in on the rotors. During burn in the pad deposits material on the rotor and the brakes start performing better. If at some point before the brakes were completely burned in they were heated up good and hot and then came to a compete stop at one point the pads would deposit a bit more material at that point. That would also create a grab point. But again you'd likely feel a pulse at slower speeds. Both of the previous are not likely but possbilites, so I'd check them.

    If every thing about the brakes checks out, rotor surface and mounting torque, calper and adapter mounting bolt torque etc. then I'd suggest experimenting with tire pressure a bit. I don't know what you are running for tires and pressure, but it might help or eliminate the problem. If you are already running your tires as low as possbile, try adding 5 to 10 psi and see what happens. If you are running a bit higher pressures try dropping 5 psi. There are also quite a few ways to run tires anymore as well, regular tires tubed or tubeless, UST set ups, wider tires on narrower XC rims and so forth. And any or all could possibly contribute to the the problem. I've seen high volume 2.3 tires on skinny 17mm XC rims do some wierd things before, nothing dangerous or anything like that, but some rather odd handling problems. But I'd say unless your running a 2.5 tire on say a mavic 717 or something similar, you're likely fine there, but you never know. So check everything and make one change at a time then test. It may be something as simple as adding or dropping 5psi in tire pressure, or going to a less agressive tread design. If you have a different set of tires laying around, try em out. Like I said, this one could be simple or it may take you a while to sort it out.

    Good Dirt
    "I do whatever my Rice Cripsies tell me to!"

  7. #7
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    thanks a bunch, il be sure to try all these experiments to figure things out.
    Bob

  8. #8
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    i threw on a specialized tire on the back (different from the high roller i was running (2.35)) and the bike did the same thing. i am thinking if i lower the rotor size to a 6 inch from an 8 inch the problem will stop. i am actually pretty sure it will, but i dont know if i want to lose the braking power.

    anyway.....

  9. #9
    Commit or eat sh!t
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    Check your rotors for warping. Possibly the calipers weren't installed properly. Or maybe its your suspension. Single pivots cause brake jacking.

    Did your problem happen with your previous brakes?

  10. #10
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    the problem did not occur with my 6" el caminos, but with these 8" strokers it does

  11. #11
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    Braking power ?

    Quote Originally Posted by skiracr2fast4u
    i threw on a specialized tire on the back (different from the high roller i was running (2.35)) and the bike did the same thing. i am thinking if i lower the rotor size to a 6 inch from an 8 inch the problem will stop. i am actually pretty sure it will, but i dont know if i want to lose the braking power.

    anyway.....
    There is very little braking effect from the rear brake vs. the front brake. Eight inch rear rotors are overkill unless your jumping off cliffs. In which case a parachute might be a better solution.

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