Avid BB7 dis-funk-tion!!!
#1
Avid BB7 dis-funk-tion!!!
I have been using my bb7 from last fall, just the other day I had to adjust the pads.
The inside piston punched a hole in the pad because I adjusted it out too far. When I took the pads out to examine the thing, the outside piston came out and would not go back in. I had to remove the other piston to get the thing back in, but not until I had to remove the lock ring wire from the post of the outside piston. Then I discovered that the pistons are not magnetized so I had to put the spring back on the pads replacing them both at the same time.
Well I got it all back together and it worked fine, but on the way to town I lost the inside piston adjustment red plastic knob! Why would that fall off and how do I get a new one???
The adjustment will not stay where I put it because the plastic knob has some kind of positioning actuator in it.
Their web site has no way for the users to contact them.
There must be a simpler more heavy duty mechanical disc brake than this!!! I am thinking about Shimmono for the next bike.
The inside piston punched a hole in the pad because I adjusted it out too far. When I took the pads out to examine the thing, the outside piston came out and would not go back in. I had to remove the other piston to get the thing back in, but not until I had to remove the lock ring wire from the post of the outside piston. Then I discovered that the pistons are not magnetized so I had to put the spring back on the pads replacing them both at the same time.
Well I got it all back together and it worked fine, but on the way to town I lost the inside piston adjustment red plastic knob! Why would that fall off and how do I get a new one???
The adjustment will not stay where I put it because the plastic knob has some kind of positioning actuator in it.
Their web site has no way for the users to contact them.

There must be a simpler more heavy duty mechanical disc brake than this!!! I am thinking about Shimmono for the next bike.
#2
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From: NW,Oregon Coast
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Ask your LBS to order small parts from QBP, they sell the small parts for those brakes.
SRAM website will give you part numbers , there is an 'exploded view' parts diagram.
services flow back up stream from dealers to distributors, to manufacturers .
SRAM website will give you part numbers , there is an 'exploded view' parts diagram.
services flow back up stream from dealers to distributors, to manufacturers .
#3
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From: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Sram does everything they can to have service issues handled through dealers. They're in a better position to properly assess a problem, check for related problems, and order the right parts or explain what they see to a service tech.
It's a logical way to do business, and you shouldn't fight it. After all when your car breaks down, you don't have it towed to Detroit, do you?
It's a logical way to do business, and you shouldn't fight it. After all when your car breaks down, you don't have it towed to Detroit, do you?
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FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
#4
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Joined: Aug 2006
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* The pressure foot (piston) shouldn't punch a hole in the pad, how much braking material is left on the pad ?
* Putting the pressure foot (piston) back in is a simple fix that doesn't require pulling out the inner pressure foot.
* Parts fall off when they aren't put on properly.
* BB7's are a good brake, mistakes made by the user can't be blamed on the brake.
Look:
BB7 Service Manual: https://cdn.sram.com/sites/default/fi...al_english.pdf
BB7 Setup & Installation Manual: https://cdn.sram.com/sites/default/fi...d7_English.pdf
BB7 Exploded Diagram & Part Numbers: https://www.who-sells-it.com/images/c...rts-000012.jpg
* The 2008/2009 model in the diagram is the current model.
* If you need spare parts your LBS can order them, you could also put Avid + Part Number into Google, it shouldn't be to hard to find a online shop that sells the parts. It'd probably be a good idea to get your LBS to fix the brake.
* Putting the pressure foot (piston) back in is a simple fix that doesn't require pulling out the inner pressure foot.
* Parts fall off when they aren't put on properly.
* BB7's are a good brake, mistakes made by the user can't be blamed on the brake.
Look:
BB7 Service Manual: https://cdn.sram.com/sites/default/fi...al_english.pdf
BB7 Setup & Installation Manual: https://cdn.sram.com/sites/default/fi...d7_English.pdf
BB7 Exploded Diagram & Part Numbers: https://www.who-sells-it.com/images/c...rts-000012.jpg
* The 2008/2009 model in the diagram is the current model.
* If you need spare parts your LBS can order them, you could also put Avid + Part Number into Google, it shouldn't be to hard to find a online shop that sells the parts. It'd probably be a good idea to get your LBS to fix the brake.
Last edited by cobba; 03-03-13 at 07:37 AM.
#5
QBP requires a large order.....I am not telling lies here, I had to remove both of the pistons to remove the wire ring that was on the outside piston post, because it would not squeeze back together after it got stretch out when I was trying to reposition it with the spring still in place.
I was working in dim light and it was getting cold. Yes I did not realize that the outer knob had to be pushed on until it clicks over the notched outer ring of the brake body...does the manuel say to do that?
https://cdn.sram.com/cdn/farfuture/qp..._spc_rev_b.pdf
both of the pressure foot pistons have a a positioning protuberance and it did most certainly puch a hole in the pad, do I have to show you a photo?
It will take a couple days. Too bad I didn't have time to even think about photographing the whole opperation.
I hate these brakes.....I need something simpler! What is available????
And I never was able to adjust the inside red knob with my hands…. 36 spokes was too many to get my hand around, and still have gripping power.
Too bad I do not have the internet at home, so I could look up the service manuel.....Bah!
I was working in dim light and it was getting cold. Yes I did not realize that the outer knob had to be pushed on until it clicks over the notched outer ring of the brake body...does the manuel say to do that?
https://cdn.sram.com/cdn/farfuture/qp..._spc_rev_b.pdf
both of the pressure foot pistons have a a positioning protuberance and it did most certainly puch a hole in the pad, do I have to show you a photo?
It will take a couple days. Too bad I didn't have time to even think about photographing the whole opperation.
I hate these brakes.....I need something simpler! What is available????
And I never was able to adjust the inside red knob with my hands…. 36 spokes was too many to get my hand around, and still have gripping power.
Too bad I do not have the internet at home, so I could look up the service manuel.....Bah!
Last edited by jawnn; 03-04-13 at 12:35 PM.
#6
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At the LBS they/we put together a order with enough things to make the shipping worthwhile,
but I would not call it a huge order, it's not like needing to buy a bikeframe and groupset kind of order..
retail bike shops that also resell over the Web , with basiclly QBP overlay graphics in the corner
of online catalogs of theirs might be a contact .. bikeman in Maine, Universal in Portland OR?
I see : knob kit: 11.5311.916. 000 for 07 , and 010 for 08,
hydraulics.. then they do the pad wear adjustment for you,
just dont hit the brake-lever with the wheel out ..
or the auto adjust fills in the gap the disc needs to go back in.
but I would not call it a huge order, it's not like needing to buy a bikeframe and groupset kind of order..
retail bike shops that also resell over the Web , with basiclly QBP overlay graphics in the corner
of online catalogs of theirs might be a contact .. bikeman in Maine, Universal in Portland OR?
I see : knob kit: 11.5311.916. 000 for 07 , and 010 for 08,
I hate these brakes.....I need something simpler! What is available????
just dont hit the brake-lever with the wheel out ..
or the auto adjust fills in the gap the disc needs to go back in.
Last edited by fietsbob; 03-05-13 at 09:49 AM.
#7
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I had to remove both of the pistons
I was working in dim light
Well I got it all back together and it worked fine, but on the way to town I lost the inside piston adjustment red plastic knob! Why would that fall off and how do I get a new one???
Yes I did not realize that the outer knob had to be pushed on until it clicks over the notched outer ring of the brake body...does the manuel say to do that?
https://lmgtfy.com/?q=Avid+BB7+Pad+Adjuster+Knob+Kit
The BB7 Service Manual doesn't say 'clicks' but it does say that the Adjuster Knobs need to be pressed firmly into place, if they're pressed firm enough they will 'click' into place. The metal piece that fits in the slot of the Outboard Adjuster Knob is called a Foot Screw, it needs to be in the correct position when the Outboard Adjuster Knob is put back on, if it isn't the knob won't go on properly.
both of the pressure foot pistons have a a positioning protuberance and it did most certainly push a hole in the pad, do I have to show you a photo?
It will take a couple days.
It will take a couple days.
I'd like to see a photo of this pad with a hole in it.
The adjustment will not stay where I put it because the plastic knob has some kind of positioning actuator in it.
Outboard Adjuster Knob > Foot Screw > Drive Cam > Pressure Foot > Pad
The Foot Screw fits into the Outboard Adjuster Knob and screws into the Drive Cam.
The Pressure Foot (male part) fits into the Drive Cam (female part).
When the Outboard Adjuster Knob is turned clockwise the Foot Screw pushes the Pressure Foot outwards from the Drive Cam and inwards towards the rotor.
When the Outboard Adjuster Knob is turned anticlockwise after it has been turned clockwise the Foot Screw will not pull the Pressure Foot back into the Drive Cam, the Pressure Foot needs to be pushed back into the Drive Cam, this is done when the brake is actuated, the pads pushing against rotor will push it back in, it can also be done with a screwdriver if the pads and rotor/wheel is removed.
* If the Outboard Adjuster Knob is turned 3 full turns clockwise the Pressure Foot will dislodge from the Drive Cam and it will need to be pushed back into it.
* If the Outboard Adjuster Knob is turned clockwise even more the Foot Screw will fully unscrew from the Drive Cam and the flat end of it that fits in the slot of the Outboard Adjuster Knob can come out, if this happens the Foot Screw needs to be screwed back into the Drive Cam and the flat end of it needs to be positioned back in the Outboard Adjuster Knob before the Pressure Foot can be pushed back into the Drive Cam.
The BB7 Service Manual describes how to Pressure Foot back in whan it comes out.
And I never was able to adjust the inside red knob with my hands…. 36 spokes was too many to get my hand around, and still have gripping power.
There must be a simpler more heavy duty mechanical disc brake than this!!! I am thinking about Shimano for the next bike.
The inner pad adjustment on Shimano mechanicals is done with a allen key, you can also adjust the inner pad on a BB7 with a allen key too.
A Shimano mechanical disc brake won't be any better then a BB7 and you'll probably have similar problems if you pull one of those apart without knowing what you're doing.
If you knew what you were doing when you pulled the BB7 apart there wouldn't of been any of the problems you're having now.
Last edited by cobba; 03-05-13 at 12:44 PM.
#8
photos
wouldn't that be nice... to know what I was doing. I am not the first one to loose the knob off these things, so say the big bike shop I went to get a knob kit. Only$8.39?
I was thinking that maybe a grain of sand got in between the plate and the pad, what else could do that.


this is the T handle torx I had to use to adjust the wheel side

so this is as good as a disc brake can be?
I was thinking that maybe a grain of sand got in between the plate and the pad, what else could do that.
this is the T handle torx I had to use to adjust the wheel side
so this is as good as a disc brake can be?
Last edited by jawnn; 03-05-13 at 12:24 PM.
#9
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so this is as good as a disc brake can be?
there are hydraulic disc brakes that ,as a pair, may cost more
than you were willing to spend for the whole bike.
What you wrote, sounds like you have tried to do work you did not prepare yourself to do.
and messed up the job.. thats not the part's fault.
the AVid Pads themselves fit into the caliper, held in, just with the return spring,
Im guessing, other than backing off the previously done pad wear adjustments,
you did not have to do more than just replace the pads, themselves.
Last edited by fietsbob; 03-05-13 at 12:42 PM.
#11
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From: Gaseous Cloud around Uranus
Those pads are overheated and falling apart.....They look like they might have actually been glowing at some point......Purple is not the correct color for the backing plate....
They got a severe work out.Even metal turns to butter if you get it hot enough.

They got a severe work out.Even metal turns to butter if you get it hot enough.
Last edited by Booger1; 03-05-13 at 01:26 PM.
#12
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From: NW,Oregon Coast
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If you are smoking brake pads, coming Fast, off Mountains, consider . going to the largest disc size,
210, vs 160,
and one with a center hub of aluminum, as a heat sink, and maybe the brake pad backing of aluminum..
another heat dissipation advance. You will probably go through a Lot of pads and Discs riding agressively..
In a Hydraulic Disc Brake, hard braking Heats the Brake Fluid and forces it into
the expansion tank in the lever.
210, vs 160,
and one with a center hub of aluminum, as a heat sink, and maybe the brake pad backing of aluminum..
another heat dissipation advance. You will probably go through a Lot of pads and Discs riding agressively..
In a Hydraulic Disc Brake, hard braking Heats the Brake Fluid and forces it into
the expansion tank in the lever.
#13
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Joined: Sep 2007
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From: Gaseous Cloud around Uranus
If your running brakes this hard,your need more mass,to help get rid of heat.....bigger everything!
Hydraulic brakes help take some of the heat away.....I know in cars and motorcycles,you can boil the fluid if you try hard enough.....I guess if your on a big enough hill you could do it on a bicycle.
Hydraulic brakes help take some of the heat away.....I know in cars and motorcycles,you can boil the fluid if you try hard enough.....I guess if your on a big enough hill you could do it on a bicycle.
Last edited by Booger1; 03-06-13 at 11:29 AM.
#14
The color you see on one of the photos is from light reflecting off my hand that was holding the camera. Bith photots are of the same pad.
I do ride downhill with heavy cargo, so maybe they did get a bit hotter than they should, but I wonder if they come with organic pads and they may be a bit softer. Now I got the metal sintered pads.
The only thing I know for sure is that none of this would have happened if the plates were magnetized.
Is Tektro the only one with magnetic pressure plates???
I do ride downhill with heavy cargo, so maybe they did get a bit hotter than they should, but I wonder if they come with organic pads and they may be a bit softer. Now I got the metal sintered pads.
The only thing I know for sure is that none of this would have happened if the plates were magnetized.
Is Tektro the only one with magnetic pressure plates???
#16
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What type of rotor are you using and what size is it ?
The only thing I know for sure is that none of this would have happened if the plates were magnetized.
What's wrong with the Pad Spreader that's sandwiched between the 2 pads, it seems to work for most people, why doesn't it work for you?
Is it possible that the brake pad with the hole in it might of had some flaws from when it was made.
When people want to upgrade their cheap low end mechanical disc brake to a better mechanical disc brake the BB7 is usually at the top of the list of what to get.
* The Type F BBDB (the first 'BB7' model) that was made from about 1999 to 2001 had magnets in the Pressure Feet.
#17
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From: Gaseous Cloud around Uranus
I put BB7 on my touring bike recently,they came with some type of sintered pad in them.....looks like copper.They lasted 2 days.....
Everytime I used the brakes it sounded like somebody replaced 2 nickles for my pads.....Worked good,just too aggressive for the touring bike.Changed to EBC green.....much better for the street.
Quiet when wet and dry.
Changing to a magnetic type holder will do nothing.....It burned a hole through the backing plate because that's where the "piston" hits the pad,so that's where heat gets transfered.If the piston was not touching the pad,no heat would have been transfered and the pad would be fine.
In order to keep from cooking pads,everything needs to have enough mass in order to draw the heat from the pads.Calipers are part of that process.Bigger rotors will help hold/dissipate heat faster,that's about your only option on bicycles......Unless somebody makes 4-6 piston calipers for bicycles....
It worked correctly,it just couldn't get rid of the heat fast enough.
Everytime I used the brakes it sounded like somebody replaced 2 nickles for my pads.....Worked good,just too aggressive for the touring bike.Changed to EBC green.....much better for the street.
Quiet when wet and dry.
Changing to a magnetic type holder will do nothing.....It burned a hole through the backing plate because that's where the "piston" hits the pad,so that's where heat gets transfered.If the piston was not touching the pad,no heat would have been transfered and the pad would be fine.
In order to keep from cooking pads,everything needs to have enough mass in order to draw the heat from the pads.Calipers are part of that process.Bigger rotors will help hold/dissipate heat faster,that's about your only option on bicycles......Unless somebody makes 4-6 piston calipers for bicycles....

It worked correctly,it just couldn't get rid of the heat fast enough.
Last edited by Booger1; 03-07-13 at 11:29 AM.
#19
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Joined: Aug 2012
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From: Colorado Springs
Bikes: Borealis Echo, Ground Up Designs Ti Cross bike, Xtracycle, GT mod trials bike, pixie race machine
The bb7 can easily be argued to be the best mechanical on the market, the only real problem I have seen is the plastic adjuster knob can melt if you let the brakes get hot enough, long enough. If you set them up properly you would not have to adjust them so far out that the pressure foot can actually fall out, especially if there is still pad material left.
#20
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Magura Gustav was a 2 piston caliper. but they were both on the outside,
pushing the disc into an inside fixed pad, like most of the Mechanical brakes do.
now Hydraulics have slave cylinder pairs, moving into the disc from both sides.
pushing the disc into an inside fixed pad, like most of the Mechanical brakes do.
now Hydraulics have slave cylinder pairs, moving into the disc from both sides.
#21
Well maybe I should take the new pads back and get the organics....
The reason I know that the magnetic plates are trouble free is that I have one Tektro on my recumbent and it it is so easy to remove the pads and replace them. And the plates stay where they are with out a spring spreder to mess with.
Don't bother to tell me I am wrong, I hate mechanic work in the freezing cold.
I understand why mechnics would like the more complex brakes. Working in a warm shop....
The reason I know that the magnetic plates are trouble free is that I have one Tektro on my recumbent and it it is so easy to remove the pads and replace them. And the plates stay where they are with out a spring spreder to mess with.
Don't bother to tell me I am wrong, I hate mechanic work in the freezing cold.
I understand why mechnics would like the more complex brakes. Working in a warm shop....
#22
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Joined: Aug 2012
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From: Colorado Springs
Bikes: Borealis Echo, Ground Up Designs Ti Cross bike, Xtracycle, GT mod trials bike, pixie race machine
Well maybe I should take the new pads back and get the organics....
The reason I know that the magnetic plates are trouble free is that I have one Tektro on my recumbent and it it is so easy to remove the pads and replace them. And the plates stay where they are with out a spring spreder to mess with.
Don't bother to tell me I am wrong, I hate mechanic work in the freezing cold.
I understand why mechnics would like the more complex brakes. Working in a warm shop....
The reason I know that the magnetic plates are trouble free is that I have one Tektro on my recumbent and it it is so easy to remove the pads and replace them. And the plates stay where they are with out a spring spreder to mess with.
Don't bother to tell me I am wrong, I hate mechanic work in the freezing cold.
I understand why mechnics would like the more complex brakes. Working in a warm shop....
I would also like to emphasize bb7's are in no way complex brakes but they are nearly always set up wrong.
#23
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From: NW,Oregon Coast
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Less turnover = better knowledge.
Maybe a problem solved by raising shop rates to allow more retention & training of mechanics ,
but if people shop just for lowest price, it ain't gonna happen..
Wages + Tips are better as bartenders..
I had no great problems pulling my BB7 pads ,
put screwdriver under the pad holder like flipping pancake.
in my case I took off the glazed face on the friction material, and put them back in
Maybe a problem solved by raising shop rates to allow more retention & training of mechanics ,
but if people shop just for lowest price, it ain't gonna happen..
Wages + Tips are better as bartenders..
I had no great problems pulling my BB7 pads ,
put screwdriver under the pad holder like flipping pancake.
in my case I took off the glazed face on the friction material, and put them back in
Last edited by fietsbob; 03-08-13 at 11:50 AM.
#24
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From: Colorado Springs
Bikes: Borealis Echo, Ground Up Designs Ti Cross bike, Xtracycle, GT mod trials bike, pixie race machine
I am guessing this was meant for the what mechanics want you to do topic?
#25
It looks like they should just include the owner’s manual with the brake. All I saw was the installation instructions.
There is a real problem with the bike industry not enough really simple parts that people can work on without reading a manual.
So far no one has said why this brake is so “good”. Seems like your all in defense of it without considering the fact that most commuters do not want to work on their bikes at any time, least of all in the cold on the road etc.. This is why you see people bring their bikes into a shop just to have a flat tire fixed. I can’t afford to pay someone else to do it. And I have no car to transport a dysfunctional bike.
I would really like to get a brake that’s as simple as the Tectro but made of stainless steel. Maybe more magnet strength on the plates? Not that I go jumping around off road.
There is a lot of room for the industry to improve commuter bikes. I had to design and build the bike in the avatar because I could not find one like it at any price.
There are several excelent disc breaks with magnetic pressure plates.
cable pull https://www.hayesdiscbrake.com/brakes/mechanical/
hydrolic https://www.hopetech.com/page.aspx?itemID=SPG28
hydrolic https://www.magura.com/en/bicyclecomp...sc-brakes.html
There is a real problem with the bike industry not enough really simple parts that people can work on without reading a manual.
So far no one has said why this brake is so “good”. Seems like your all in defense of it without considering the fact that most commuters do not want to work on their bikes at any time, least of all in the cold on the road etc.. This is why you see people bring their bikes into a shop just to have a flat tire fixed. I can’t afford to pay someone else to do it. And I have no car to transport a dysfunctional bike.
I would really like to get a brake that’s as simple as the Tectro but made of stainless steel. Maybe more magnet strength on the plates? Not that I go jumping around off road.
There is a lot of room for the industry to improve commuter bikes. I had to design and build the bike in the avatar because I could not find one like it at any price.
There are several excelent disc breaks with magnetic pressure plates.
cable pull https://www.hayesdiscbrake.com/brakes/mechanical/
hydrolic https://www.hopetech.com/page.aspx?itemID=SPG28
hydrolic https://www.magura.com/en/bicyclecomp...sc-brakes.html
Last edited by jawnn; 03-25-13 at 12:21 PM.



