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  1. #1
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    Tuning V Brakes.... what's the art?

    My bike is set up with Single Digit 3 brakes on LX levers and the braking sucks pretty bad and I'm looking for any tricks or tips to improve the performance. The brakes are adjusted to contact the rim with very little pull, but on steep descents, I can have the front lever touching the grips with the front wheel still turning. I'm only 160 lbs too..so it' so I don't think the brakes should have any problems. I mainly ride xc, so I don't see a lot of steep downhill, but this lack of stopping power is definitely keeping me from taking sections faster.

    Are there any tuning tricks I can try to improve performance? Maybe different pads? I'm not against upgrading components, but I am on a tight budget....and while that budget could include hydro discs, I can't afford to replace my current wheel set with a disc equivalent, so I'd rather try and get the V brakes working.

  2. #2
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    Try some different compound pads first. You can also take some fine steel wool or a scuff pad to clean up any glaze on the rim braking surface. Do your LX levers have the little dials that let you tune the braking feel?

  3. #3
    Bicyclochondriac.
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    Quote Originally Posted by vortmax View Post
    My bike is set up with Single Digit 3 brakes on LX levers and the braking sucks pretty bad and I'm looking for any tricks or tips to improve the performance. The brakes are adjusted to contact the rim with very little pull, but on steep descents, I can have the front lever touching the grips with the front wheel still turning. I'm only 160 lbs too..so it' so I don't think the brakes should have any problems. I mainly ride xc, so I don't see a lot of steep downhill, but this lack of stopping power is definitely keeping me from taking sections faster.

    Are there any tuning tricks I can try to improve performance? Maybe different pads? I'm not against upgrading components, but I am on a tight budget....and while that budget could include hydro discs, I can't afford to replace my current wheel set with a disc equivalent, so I'd rather try and get the V brakes working.
    Good pads make a huge difference.

    Also, it sounds like you are getting a lot a flex in the brakes somewhere. You might want to look into a brake booster, they really make a huge difference if the flex is between the brake bosses on the frame or fork.

    Finally, good cables. I run Jagwire Ripcord cables (on both V-Brakes and mech disc), full length. If you have the stock cables and housing on this bike, the Ripcords will definitely help.
    15mm is a second-best solution to a problem that was already solved.

  4. #4
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    Agreed on the pads. Kool Stops are a good choice.

    You might also check pad alignment and toeing. This Park guide tells you how to do that: Park Tool Co. ParkTool Blog Linear Pull Brake Service (V-brake style)

    Good luck!
    "Never trust a man in a blue trench coat. Never drive a car when you're dead." -- Tom Waits

  5. #5
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    As others have stated:
    -Proper adjustment
    -Good pads
    -Solid cables and housing

    My preference for pads was the Kool Stop Mountain Pads in the Salmon compound. Cable housing makes a big difference. The standard generic "coiled" brake housing has way too much flex in it. The Jagwire Ripcord or Sram Full Metal Jacket cables and housing will provide a much better flex free platform.

  6. #6
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    Sheldon Browns website has all sorts of good tricks for direct pull brakes:

    Adjusting Direct-pull Cantilever Bicycle Brakes ("V-Brakes ")

  7. #7
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    Thanks guys. I have scrubbed the brake track and adjusted the crap out of the current ones with little to no effect. It looks like I'll start with some new pads and use this as an excuse to re-cable. I don't think the cable runs are long and straight enough (plus some are internal) for FMJ cables. Does anyone have an opinion on ripcord vs flack jacket?

    Also, I'm only having issues with the front brake. Would a brake booster still make a noticeable difference?

  8. #8
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    Quote Originally Posted by vortmax View Post
    Thanks guys. I have scrubbed the brake track and adjusted the crap out of the current ones with little to no effect. It looks like I'll start with some new pads and use this as an excuse to re-cable. I don't think the cable runs are long and straight enough (plus some are internal) for FMJ cables. Does anyone have an opinion on ripcord vs flack jacket?

    Also, I'm only having issues with the front brake. Would a brake booster still make a noticeable difference?
    Personally I have not had any problems getting good power even with cheapo brake housing. I have used Aztec pads with consistently good results, as well as Kool-Stop (I think they make some dual-compound ones).

    If all your stuff is aligned properly and still not enough power, then I would blame the pads. Although the fact that the lever reaches the grip makes me think maybe the pads are toed in a little too far. Flexy brakes need more toe-in to level them out under hard braking. If your brakes aren't too flexy, toe-in can be about the thickness of a business card. That is my typical set-up for Shimano V-brakes. You'll get good contact and no squeak.
    Some of the longer brake pads have the toe-in molded into them in the form of little dots or sort of a tiny "tail" on the trailing edge of the brake pad. You can just mount them flat and they will wear in fairly quickly when the dots or the "tail" rub off.

    -F
    It's never easier - you just go faster.

  9. #9
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    On my MTB I switched to Koolstop pads, cleaned the rims and the difference was amazing. I highly recommend them. I also put some Shimano Acera v-brakes on my wife's bike with M590 levers and the performance is also impressive.

  10. #10
    Heavylegs
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    Hey vortmax, did you just install these brakes recently? If so what kind of brakes were on the bike before?

  11. #11
    Bicyclochondriac.
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    Quote Originally Posted by vortmax View Post
    Also, I'm only having issues with the front brake. Would a brake booster still make a noticeable difference?
    It depends on how much the fork brake bosses flex out when you squeeze the brake. It is easy enough to check.

    On my old Z2 Superfly the flex was really bad and the booster made a night and day difference. On my X-Vert, it was pretty solid, and the booster made little difference. I set some v-brakes up on a Tora, and that was rock solid as well. I doubt a booster would have made any difference.

    What kind of fork do you have?
    15mm is a second-best solution to a problem that was already solved.

  12. #12
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    Might want to try derailleur cables and housing.
    The compressionless housings mad a big difference on my bikes.
    Lenny

  13. #13
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    Quote Originally Posted by OneEyeMan View Post
    Might want to try derailleur cables and housing.
    The compressionless housings mad a big difference on my bikes.
    Lenny

    Per Sheldon Brown: Bicycle Brake and Shift Cables from Harris Cyclery :

    DO NOT USE SHIFT CABLE HOUSING FOR BRAKE LINES!!! It is not made to handle the force applied during braking. See my Cables article for details.

    Just sayin'.

    -F
    It's never easier - you just go faster.

  14. #14
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    Quote Originally Posted by redd4573 View Post
    Hey vortmax, did you just install these brakes recently? If so what kind of brakes were on the bike before?
    Nope, these are the stock brakes.

    The fork is a manitou sx-r

  15. #15
    Bicyclochondriac.
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    Quote Originally Posted by OneEyeMan View Post
    Might want to try derailleur cables and housing.
    The compressionless housings mad a big difference on my bikes.
    Lenny
    Better yet, use something like Jagwire Ripcords and get all the benefits of both shifter and brake cable/housing.

    Shifter housings are compression-less due to the metal wires running parallel to the cable. This is great for eliminating compression along the length of the housing (critical for precise shifting), and when used with brakes they give a very solid feel. However, they not meant for the heaving stresses that brake cables put on them against from the inside out, since the individual strands are more easily separated.

    Typical brake housing has the metal spiral-wrapped around the core, thus it is very resistant to splitting. The problem is that it is also more easily compressed along the length, thus giving you more flex in the system.

    With Ripcords (and maybe others) you have both types of metal reinforcements. Thus you have a housing that is compression-less like a shifter cable, but holds up to the forces of braking.

    Also, how do you use shifter cables on a brake lever? The ball at the end is too small, isn't it?
    15mm is a second-best solution to a problem that was already solved.

  16. #16
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    Cleaning the rim and replacing or resurfacing the pads will do a lot of good. I'd do that first as it's the cheapest and most effective plan. I've used brake boosters before (cheap ones). They're quite effective at limiting flex. I used it on my rear brakes and performance went through the roof.

    I'm sure upgraded cable housing will make a noticable difference, but I'm not so sure it's the first thing you'd want to take care of. Same with the booster. If you're pulling that much on the lever but you're not locking up the wheel, it's a tuning issue, not an issue with the quality of the components.

  17. #17
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    Make sure the two brake arms are just outside parallel when applied. You may need to add a washer between the pad and brake arm to increase the angle. Make sure the pads are perpendicular to the rim. V brakes are easy to set up because you can lightly pull the lever to hold the brake pad in place while you tighten the set bolt/nut. A business card between the rim and rearward end of the pad insures proper toe. Lightly sand the pads (try koolstop pads) and clean the rim with fine sandpaper, then rubbing alcohol. Drop of triflow in the noodle and cable.

  18. #18
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    Has it always been like this or has anything changed recently?

  19. #19
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    Quote Originally Posted by IntensevCare View Post
    ...V brakes are easy to set up because you can lightly pull the lever to hold the brake pad in place while you tighten the set bolt/nut....
    Another trick is to release the long arm of the spring in the brake arm on the side you are adujsting. Spring tension in the other arm holds the pad against the rim, leaving both hands free to hold the pad in place while you tighten it down.
    Quote Originally Posted by JonathanGennick View Post
    I am a poser. But forums.poser.com doesn't seem to exist, so I come here instead.

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