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Thread: bb7 issues

  1. #1
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    bb7 issues

    Bought a pair of MTB BB7 with 185mm g2 clean sweep rotors for front and rear. I'm using the stock pads right now. I've done a break in on the brakes on a boat launch ramp which is stupid of me but several fast down hill burn ins seemed to make it a lot better. However still not as good as my old Hayes MX-1's 160mm which I've flown across the bars at least once. Now when I grip the front all the way, the brake arm seems to just flex and not provide adequate grip. I can go full speed, stand up and hold it down as hard as I can and it still wont lock up or slow me down compared to my old brakes.

    The back brakes seem fine although it does flex. I've rotated the pads around and same thing. My front tires grip alot better than the back and im pushing 220lbs but thats why i got the 185's. Perhaps these need better pads. I ran cheap ebay chinese semi-metallic on my old hayes. Don't know what the ones on the bb7's are. If anyone can help. That Would be awesome.

    PS all the equipment is the same except the rotors and calipers.

  2. #2
    utilikilted
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    Quote Originally Posted by fusionstar
    PS all the equipment is the same except the rotors and calipers.
    To clarify, are you using Avid or Hayes levers?

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    Quote Originally Posted by Shuteye
    To clarify, are you using Avid or Hayes levers?

    I am actually using shimano deore lever\shifters. When I clamp down and the pads bite. The brake arm on the caliper continues to bend. Thanks

  4. #4
    utilikilted
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    Quote Originally Posted by fusionstar
    I am actually using shimano deore lever\shifters. When I clamp down and the pads bite. The brake arm on the caliper continues to bend. Thanks
    I have only used BB7's with Avid's FR7 levers, and had plenty of braking power with 160mm rotors front and rear on 1 mile or more Sierra descents. I weigh 180 ready to ride with hydration pack. If rotors and pads are not contaminated it may be levers. Hopefully someone with a similar set up as yours will add their two cents worth.
    Last edited by Shuteye; 02-19-2011 at 10:29 PM.

  5. #5
    R.I.P. DogFriend
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    Stock pads work just fine. Yours may be contaminated.

    This is what works for me when I have trouble with BB7's: I remove the pads, knock the glaze off of them with some sandpaper (put the sandpaper on a flat surface and then lightly rub the pad with even pressure), and then spray them off with some brake cleaner. Wipe your rotors down with rubbing alcohol. Adjust the brakes as the instructions advise, and then find a loooooooooooong downhill (at least a mile if possible). Ride downhill while keeping the brake applied lightly at first. Let off every so often and keep steadily applying more pressure, but not enough to make them squeal. By the time you get to the bottom, you should be able to hit them pretty hard and not get any squeal. They should be fairly strong, but they won't be quite up to full power. That will come around in a ride or two. Works everytime for me.

    I weigh 260lbs and have BB7's on all of my bikes and all of my kid's bikes (5 bikes). They work great.

  6. #6
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    I have BB5's on a commuter bike and today I had total brake failure 1/2 through a ride. It was more effective for me to hop of the bike to stop then squeeze the brakes as hard as I could.

    I was convinced that I have been negligent and let the pads wear all the way to the backing materials, but after the ride I found out that there is a lot of breaking material left.

    FYI it was a very wet ride and I did ride some fire roads and before the ride adjusted the cable so that I was not pulling the levers to the bars.

  7. #7
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    how are they set up? the inner pad needs to be closer to the rotor, barley out from rubbing. the outer pad can be as close for a solid feel or a little further out for more progressive feel. either way, the inner pad doesn't move so having it set close is key.

    once you have them set up right, clean the rotors and pads as described above. should stop fine.

  8. #8
    I Tried Them ALL... SuperModerator
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    Yeah, go with either the Avid FR-5 or SD-7 levers...they are specifically designed for BB7.
    "This is a male-dominated forum... there will be lots of Testosterone sword-shaming here" ~ Kenfucius

  9. #9
    utilikilted
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    Quote Originally Posted by fusionstar
    I am actually using shimano deore lever\shifters. When I clamp down and the pads bite. The brake arm on the caliper continues to bend. Thanks
    If I understand you right, you are using integrated deore lever/shifters. It will cost you a bit of change to go to seperate shifters and Avid levers. If rotors and pads are in good shape, then my question would be "Do deore levers work well with BB7's?" I can't answer that for you but maybe someone on this forum has run deore levers with BB7's, either integrated or seperate, as both should function the same.

  10. #10
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    I ran BB7's with Alivio integrated shifter/levers. No problem with stopping power but they felt like $hit. Too firm or too soft depending on how close the pads were to the rotor. The upgrade will run you about $60 for a decent set of shifter pods and levers. See about finding some used shifters. The levers are cheap enough to buy new.

  11. #11
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    Set-up issue perhaps?

    Quote Originally Posted by fusionstar
    Now when I grip the front all the way, the brake arm seems to just flex and not provide adequate grip. I can go full speed, stand up and hold it down as hard as I can and it still wont lock up or slow me down compared to my old brakes.
    This may be a stretch, but could it just be a set up issue? If the pads are dialed in close enough to the rotor, grabbing a handful of brake should stop you on a dime. Check to see that the inboard and outbard adjustments are correct, AND that the cable is installed correctly. Too much slack and it won't pull hard enough to give sufficient braking power.

    Bob

  12. #12
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    Quote Originally Posted by Call_me_Clyde
    This may be a stretch, but could it just be a set up issue? If the pads are dialed in close enough to the rotor, grabbing a handful of brake should stop you on a dime. Check to see that the inboard and outbard adjustments are correct, AND that the cable is installed correctly. Too much slack and it won't pull hard enough to give sufficient braking power.

    Bob
    The OP was talking about the caliper bending. That's not possible. He must mean the rotor is bending. Which means,as you said, an adjustment problem.

    Sounds like he's adjusting the brakes by using the barrel adjusters and shortening the cable. After enough pad wear, the brakes can lose more than 50% of their power with this method of adjustment.

    BB7's should be adjusted only at the caliper. After new pads are installed and adjusted, your levers will get closer to the bars as the pads wear. If you use the barrel adjusters to compensate for this, you are making your brakes weaker. If you adjust ONLY at the calipers, the brakes will maintain full power throughout the pad life. NEVER adjust by shortening the cable - only use the big red pad adjusting knobs. Barrel adjusters are to be used only to make up for cable stretch - not pad wear

    The BB5 brakes have no outer pad adjustment knob so you must shorten the cable as the pads wear which reduces power. They get progressively worse until they won't stop you unless you use extreme lever pressure. Maybe the OP has BB5's? Sure sounds like it. The only way to make BB5's work well is to replace the pads every few months. After all, with new pads and proper alignment, they do stop as well as BB7's.

  13. #13
    Never trust a fart
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    Quote Originally Posted by bigbeck
    The BB5 brakes have no outer pad adjustment knob so you must shorten the cable as the pads wear which reduces power. They get progressively worse until they won't stop you unless you use extreme lever pressure. Maybe the OP has BB5's? Sure sounds like it. The only way to make BB5's work well is to replace the pads every few months. After all, with new pads and proper alignment, they do stop as well as BB7's.

    Actually with the BB5's you make the pad adjustments with the inner knob AND the caliper lever where the cable attaches.

    He should not have to replace the pads every few months. That is silly and a waste of money.
    They should only be replaced if worn out or contaminated.

  14. #14
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    Quote Originally Posted by frdfandc
    Actually with the BB5's you make the pad adjustments with the inner knob AND the caliper lever where the cable attaches.
    And that is precisely why the BB5's lose 50% or more of their original braking power when the pads are very worn. If you've never experienced this with BB5's, then you've never worn the pads down far enough. In fact, all of the cable discs with a single pad adjustment have this problem. The reason they lose their power is that the more you move the actuating lever the more leverage is lost. The lever on the caliper needs to be near the bottom of it's stroke when the pads hit the disc.

    As a matter of fact, you can easily mimic the inferior performance of BB5's on the BB7 brakes.
    With well worn properly adjusted BB7 pads, back off the outer adjustment knob quite a bit until your lever hits the bar. Now, adjust the cable at the caliper so you have a "full" lever. This is how you adjust the BB5's and most other mechanical discs. Guaranteed you'll be shocked at the loss of power. And the sole reason for this is that the caliper lever is in mid stroke when the pads hit the rotor, where it's leverage ratio is very low. The more the pads wear, the weaker the brakes get. The bb7's do not suffer from this problem and it's only because it has the outer adjustment knob, which, when adjusted properly, always keeps the caliper lever at the bottom of it's stroke, where it's most powerful.

    This is not rocket science, it's just an extremely simple leverage type device. More pressure on the pads equals more stopping power. If you can't understand the basic leverage concept,then you'll never understand why the BB7 is so much better than other cable discs that do not have an outer pad adjuster.

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