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  1. #1
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    BB7 post install question

    i got my BB7 installed in the front and its rather slippery but seems to be getting better with every ride. Defiantly better today than yesterday, but it keeps raining so its hard to test them.

    My question involves the brake lever. I used the same jagwire housing/cables that my bike came with, which I also used on my BB5's. Though now I notice that when I press on the front brake I can press hard and get the brake to engage, but I can continue to press on the lever, even though the brake is fully engaged. The engagment of the lever has about a 1:1 ratio with the calipers actuating arm, a light push on the lever creates a equal pull on the arm. When I hit the middle of the lever's engagement the actuating arm is about 1/2 way of its potential, though as I squeeze harder it keeps going all the way to reach its potential.

    I really cant understand the mechanics of such a operation, one would think the outboard pad would have no place to go. The calliper is centred perfectly 1/3 to the outboard and 2/3 to the inboard. The rotor has the slightest flex upon engagement but that seems to be expected.

    I am not as of yet at the over the handle bar stage with these brakes.

  2. #2
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    Quote Originally Posted by BeaverTail
    i got my BB7 installed in the front and its rather slippery but seems to be getting better with every ride. Defiantly better today than yesterday, but it keeps raining so its hard to test them.

    My question involves the brake lever. I used the same jagwire housing/cables that my bike came with, which I also used on my BB5's. Though now I notice that when I press on the front brake I can press hard and get the brake to engage, but I can continue to press on the lever, even though the brake is fully engaged. The engagment of the lever has about a 1:1 ratio with the calipers actuating arm, a light push on the lever creates a equal pull on the arm. When I hit the middle of the lever's engagement the actuating arm is about 1/2 way of its potential, though as I squeeze harder it keeps going all the way to reach its potential.

    I really cant understand the mechanics of such a operation, one would think the outboard pad would have no place to go. The calliper is centred perfectly 1/3 to the outboard and 2/3 to the inboard. The rotor has the slightest flex upon engagement but that seems to be expected.
    So the question is something like "Why can I continue to squeeze and move the brake lever even after the caliper is fully engaged?" ?

    If that's the question, my guess is that the brake cable housing is compressing. Try using better housing. It could be too that the ends aren't squared off and are allowing some movement within the ferrule.

  3. #3
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    Yeah but the same thing never occurred on the BB5's. The same exact cable and all. Il go take a look but the cable is from jagwire and made for my bike, im pretty sure it would be close to perfect.

    il give it a look. thank you.

  4. #4
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    How long does it usually take to get get complete lockout easily on both the front and the rear with little force on the lever? As I right now I stop, but dont stop fast, can make back tire skid but it takes insane pressure on the lever.

    All cables seem good but the rear cables moves a lot when I engage it, is this just a sign of poor cables?

  5. #5
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    Quote Originally Posted by BeaverTail
    How long does it usually take to get get complete lockout easily on both the front and the rear with little force on the lever? As I right now I stop, but dont stop fast, can make back tire skid but it takes insane pressure on the lever.

    All cables seem good but the rear cables moves a lot when I engage it, is this just a sign of poor cables?
    I can't say if it's the cables, but something seems wrong with your set-up. I can lock up my BB7s, especially the rear, without a lot of effort.

  6. #6
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    you could lock them up right from the start? I am a bigger guy so It takes alot more to stop me then lets say a 150lb man. I weigh around 330lbs. Though my BB5's had little trouble doing this/

  7. #7
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    Quote Originally Posted by BeaverTail
    you could lock them up right from the start?
    Pretty much. It usually takes a few hard stops, but then they'll lock up easily.
    I am a bigger guy so It takes alot more to stop me then lets say a 150lb man. I weigh around 330lbs. Though my BB5's had little trouble doing this/
    Yeah, I weigh less than you, between 205 and 210 depending on the day. If you were able to lock up your BB5s, then there's something wrong with your BB7 set up. It is puzzling that the same cables and housing worked great with the BB5s, but not with the BB7s.

    When you squeeze the lever so that the caliper is fully engaged, and then continue to squeeze it for a while yet, can you see where that mushiness is coming from? Watch the housing and the endpoints carefully whilst squeezing the lever to see if there's any movement...

  8. #8
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    Quote Originally Posted by BeaverTail
    you could lock them up right from the start? I am a bigger guy so It takes alot more to stop me then lets say a 150lb man. I weigh around 330lbs. Though my BB5's had little trouble doing this/
    good to know, me being 170lbs.
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  9. #9
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    The calipers were installed to both written and visual specification with only slight rotor flex in a 2/3 inboard and 1/3 outboard fashion.

    I looked at the brakes, housing and endpoints as you mentioned and made these findings.

    -Front housing flexes when front brake is engaged.

    -When you put excessive force on the lever it seems the front caliper moves slightly to the wheel, but then comes back when released. Its not a big moment, though it seems the caliper is turning slightly away from its point point.

    -The cable to the rear brake compresses and flexes a lot where it turns around the seat stay and is secured by a zip tie.

    -I noticed that when I push extra hard on the lever it is likely the internal spring of the BB7eating up the extra applied force.



    My BB5's could stop me on a dime, one hard press to the front and I was over the bars and one hard press to the rear I would instantly lock up and skid even when all of my 330lbs were on the saddle. Same rotors as well. Now my back tire can lock up but I need to get off the saddle and the front is in no way able to lock out. The pads kind of just glaze me to a stop. They work as brakes, but are not really what I expected. I would say I have around 90 full stops on the front brake and 50-60 on the rear but im not exactly counting.

  10. #10
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    You didn't use the barrel adjuster to adjust cable tension, did you? Almost sounds like you're bottoming the torque arm after doing that...
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  11. #11
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    I slightly used the barrel adjusters to get rid of any cable slack, but only per the instructions. It was only around half a turn and has no affect on the actuating arm's. Even If I rid any use of the barrel adjusters I have the same problem. Given the desigh of the system it would seem to me that it shouldn't be hard to utilize the entire arms potential.

  12. #12
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    Quote Originally Posted by BeaverTail
    I slightly used the barrel adjusters to get rid of any cable slack, but only per the instructions. It was only around half a turn and has no affect on the actuating arm's. Even If I rid any use of the barrel adjusters I have the same problem. Given the desigh of the system it would seem to me that it shouldn't be hard to utilize the entire arms potential.
    If you're positive all is well with your caliper setup, levers, and cable/housing, can only think you still need some bedding in.
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  13. #13
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    we'll im not 100% sure, im not a professional mechanic. I made a post over on the clydes forum asking how long it took the bigger guys to get a good bite.

  14. #14
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    Quote Originally Posted by BeaverTail
    we'll im not 100% sure, im not a professional mechanic. I made a post over on the clydes forum asking how long it took the bigger guys to get a good bite.
    Just how much bedding in have you done?
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  15. #15
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    ive gone for only two rides so far as it keeps raining here, but in those two rides I continually stop and go, trying to work the brakes. I certainly have not gone 30 miles like some other posts have said, maybe 1.2 at most.

  16. #16
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    Quote Originally Posted by BeaverTail
    ive gone for only two rides so far as it keeps raining here, but in those two rides I continually stop and go, trying to work the brakes. I certainly have not gone 30 miles like some other posts have said, maybe 1.2 at most.
    I do it when it's dry, and use a downslope where I can repeatedly use the brake but I doubt it's even a mile's worth in total, but I get them up to a point where I'm getting some braking then finish them off on a regular ride, but still it's not that much longer before I consider them fully bedded in. Did you clean the old rotors before using the new pads?
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  17. #17
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    Quote Originally Posted by Bikinfoolferlife
    I do it when it's dry, and use a downslope where I can repeatedly use the brake but I doubt it's even a mile's worth in total, but I get them up to a point where I'm getting some braking then finish them off on a regular ride, but still it's not that much longer before I consider them fully bedded in. Did you clean the old rotors before using the new pads?
    Yeah I cleaned them quite thoroughly with 90% rubbing alcohol. I also wore medical gloves during the entire install. Maybe my pads aren't getting close enough? I tried to true the rotors but I cant get them perfect.

  18. #18
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    You using the stock metallic pads in the BB7? Any reason not to use the rotors the BB7s came with? Possibly your old rotors are excessively worn? It's possible riding in the wet to get contaminants into the mix, too (like riding through a muddy puddle laced with oil on a dirt trail used by lots of vehicles, been there done that).
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  19. #19
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    I never rode in the rain and never through dirt, only around the block on cement. I dont think the rotors are worn out given they were from a new bike only 3 months old. Both rotors probably at most had 60 miles on them. There is wear on them, but is not to the caliber of some ive seen here. and yes the stock sintered pads.

    Thanks for the help btw, I really appreciate it.

  20. #20
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    I took some pics guys, so if ya see any problems with my setup let me know, thanks. The pics are in the link below, they are seperated between front and rear.
    http://knife-bst.com/images/bike/rockhopper/brakes/

  21. #21
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    Quote Originally Posted by BeaverTail
    I took some pics guys, so if ya see any problems with my setup let me know, thanks. The pics are in the link below, they are seperated between front and rear.
    http://knife-bst.com/images/bike/rockhopper/brakes/
    I don't see anything wrong that'd cause poor braking performance.

  22. #22
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    When you guys set up your BB7's do you follow avids instructions or do you follow something more like this http://www.twowheelblogs.com/avid-bb...set-and-tuning

    I ask because I keep getting all sorts of opinions, some folks say its best to have the rotor(R) centred with [1/2 R 1/2] and others say to have it like this [2/3 R 1/3] as the avid instructions say. The notation above just describes the space between the rotor and calliper,

  23. #23
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    Any chance your 5s were organic pad while the 7s are metallic?
    PS please compress the pics next time.

  24. #24
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    well im not sure il have to ask. I didn't compress them or resize them because I wanted to keep the quality. Il put up both versions next time.

  25. #25
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    And what levers do you have? Might help to adjust the leverage.

  26. #26
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    Just the basic FR-5's from avid, I was thinking of getting new cables and levers but would rather not if possible.
    Here is a pic of the pad, I cant really see if its sintered or organic. I asked JohnsD90 to take a closer look for me.


    Last edited by BeaverTail; 11-29-2009 at 05:47 PM.

  27. #27
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    Quote Originally Posted by LWright
    Any chance your 5s were organic pad while the 7s are metallic?
    PS please compress the pics next time.
    But the metallics should perform better in any case.

    As to following Avid instructions, I've always done well with the Avid instructions with the 1/3-2/3 thing. Gives you more options on adjusting the fixed pad.
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  28. #28
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    Im pretty sure they were sintered. I realigned my front BB7 today and noticed one key thing. The piston of the outboard side continually hyper extended like was suggested in another thread her a week or so back. This is why in the pics, the pads looked so close to the rotor, even when I backed out the outboard pad all the way. I realigned the calliper to the 2/3 and 1/3 position and tightened the outboard pad while the wheel was spinning. It eventually locked the rotor down into the right position. I tightened the cps bolts and backed out both pads. I was glad to see that the outboard pad piston was not over extended and I could see a good clearance between the pads and rotor. I then tightened down the pads enough so the rotor didn't hit, which could be better but the rotor is not perfectly true.

    The performance is still not amazing, could be better but I guess it might need more bedding


    Here is a pic of the front pads of my bb7

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