REVIEWS DEALS BIKESHOPS TRAILS

Avid BB7 - Outboard pad not retracting

13767 Views 17 Replies 9 Participants Last post by 849097, Jan 19, 2020

davies1

Discussion Starter · Jan 13, 2010

Evening All,

Am new around these parts - hoping you lot can help me as weeks of searching has not helped so far!

I have a pair of Avid BB7's (May 09) that do not retract their outboard pressure feet / pads.
When you turn the pad adjuster to push the pad into the rotor, and then turn it back to bring the pad back, the pressure foot that the pad rests on does not RETRACT!

Can anyone help with this please? I'm totally stuck.

1 - 18 of 18 Posts

Bikinfoolferlife

· #2 · Jan 14, 2010

Sounds like this is your problem, here's the fix from the service manual (which you can download from the SRAM site):

troubleshooting (not pictured)
The most common issue with the BB7 is that the
outboard pressure foot can become dislodged if
the outboard adjustment knob is turned too far
clockwise without the rotor in the caliper (wheel
off or caliper removed). The brake is not broken,
nor does it require disassembly to replace the
pressure foot. To replace the pressure foot, turn
the outboard adjuster knob counter-clockwise
until it stops. If the knob doesn’t stop, then the
foot screw (the end of which can be seen in the
center of the knob) has become disengaged
from the knob and possibly from the threads
inside the drive cam. In this case, remove the
knob, then using a pair of small needle-nosed
pliers or a schrader valve tool, turn the the foot
screw all the way back out until it stops. Now
the pressure foot can be replaced. Relocate the
pressure foot into the bore, then give it a firm
push in the center. It will click back into place.
If you removed the knob, replace it and you’re
done!

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cobba

· #3 · Jan 14, 2010

The BB7's have a screw on them which allows you to adjust the amount of tension on the calliper arm spring, if there's not enough tension on the spring the calliper arm won't retract.

zarr

· #4 · Jan 14, 2010

thanks

davies1

Discussion Starter · #5 · Jan 14, 2010

Bikinfoolferlife said:
Sounds like this is your problem, here's the fix from the service manual (which you can download from the SRAM site):

troubleshooting (not pictured)
The most common issue with the BB7 is that the
outboard pressure foot can become dislodged if
the outboard adjustment knob is turned too far
clockwise without the rotor in the caliper (wheel
off or caliper removed). The brake is not broken,
nor does it require disassembly to replace the
pressure foot. To replace the pressure foot, turn
the outboard adjuster knob counter-clockwise
until it stops. If the knob doesn't stop, then the
foot screw (the end of which can be seen in the
center of the knob) has become disengaged
from the knob and possibly from the threads
inside the drive cam. In this case, remove the
knob, then using a pair of small needle-nosed
pliers or a schrader valve tool, turn the the foot
screw all the way back out until it stops. Now
the pressure foot can be replaced. Relocate the
pressure foot into the bore, then give it a firm
push in the center. It will click back into place.
If you removed the knob, replace it and you're
done!

Hi, thanks but the pressure foot hasnt become dislodged.
It just doesnt retract into the caliper housing (away from the rotor) when using the pad adjustment dial. It needs coaxing with more force than should be required.

cobba said:
The BB7's have a screw on them which allows you to adjust the amount of tension on the calliper arm spring, if there's not enough tension on the spring the calliper arm won't retract.

The caliper arm retracts fine... Its just the pad that doesnt retract into the housing. Unless the caliper arm plays a direct role in the retraction of the pressure foot in question?

Bikinfoolferlife

· #6 · Jan 14, 2010

davies1 said:
Hi, thanks but the pressure foot hasnt become dislodged.
It just doesnt retract into the caliper housing (away from the rotor) when using the pad adjustment dial. It needs coaxing with more force than should be required.

The caliper arm retracts fine... Its just the pad that doesnt retract into the housing. Unless the caliper arm plays a direct role in the retraction of the pressure foot in question?

Not sure exactly what the problem is then...just a sticky pressure foot? Does the pad not seat itself when you pull on the torque arm pushing the pad against the rotor?

davies1

Discussion Starter · #7 · Jan 14, 2010

When the clipar arm pushes the pressure foot towards the rotor it works fine. But when the caliper arm retracts, the pressure foot only retracts a small way, and stops. You need to use a little bit of force to push the pressure foot back into the caliper.

Sorry, its a pain to explain.

AlexRandall

· #8 · Jan 14, 2010

Without the pads in place, try dropping some light lube into the moving areas on the in and outside of the calliper. It sounds almost like a sticky 'piston'

Wombat

· #9 · Jan 14, 2010

Try disconnecting your cable and seeing if you still have the problem.

Tim

davies1

Discussion Starter · #10 · Jan 14, 2010

THanks Alex, shall try the lube tomorrow.

Wombat said:
Try disconnecting your cable and seeing if you still have the problem.
Tim

Doesn't matter whether the cable is anchored or not. But thanks for trying to help, keep it coming :thumbsup:

cobba

· #11 · Jan 15, 2010 (Edited)

davies1 said:
When you turn the pad adjuster to push the pad into the rotor, and then turn it back to bring the pad back, the pressure foot that the pad rests on does not RETRACT!

davies1 said:
When the clipar arm pushes the pressure foot towards the rotor it works fine. But when the caliper arm retracts, the pressure foot only retracts a small way, and stops. You need to use a little bit of force to push the pressure foot back into the caliper.

Are the pads in the brake and is the rotor between the pads when you engage the brake?

If they aren't then there probably isn't a problem with the brake, the problem is no pads, rotor or combination of the two. The pressure foot will retract back in place and stay there when you engage the brake that has pads in it and they are pushing against the rotor.

From what I can see the outboard pad adjuster has at least 2 parts which consist of the pressure foot part that has a male connection with a spring clip on the back of it which fits into adjuster screw part that has a female connection.
The pressure foot part on BB7's doesn't normally and won't automatically go back to it's original position when the pad adjuster is turned in and then turned out, the 2 parts of the pad adjuster need the calliper arm to turn and the force of the pads pushing against the rotor to seat them back into place.
The separator spring that holds the pads in place isn't strong enough to push the pressure foot with the male part and spring clip into the screw adjuster part with the female connection.

I've never noticed it before or paid any attention to it but I just looked at my brakes and the same thing happens on my BBDB's which are the older version of the BB7's.
My brakes work fine when the pads are in and a rotor is between them, the pressure foot always retracts back into place and stays there when the brake lever is pulled and the pads push against the rotor.

Basically I think that you're worrying about a problem that isn't there, it's just the way the BB7's work.

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Kibble Fat

· #12 · May 13, 2012

Signed in just to get this answer on the internet. Basically, you can ignore all replies up until this one.

-------------------------------------------------------------------------------------------------------------------------------------------------

I just disassembled the outboard side of my BB7 and found that I was having the same issue after reassembling. This has to do with the orientation of the piston's ramp/cam surfaces relative to those of the caliper body. Only one of the 3 or 4 positions will fully retract, so simply spin the piston to each position and see if it can retract until it is flush with the caliper body. If it can, you've found it's home position. Here's the step-by-step fix:

1) Remove pads and pad spring
2) Disconnect cable
3) Pry off outboard adjuster knob with a flat head screwdriver
3) Holding the arm to the side of the caliper (so parts don't go flying), remove the nut and washer. Note the washer's serrated flange is farthest outboard against the nut.
4) Carefully pull the arm off of the torsion spring.
5) Remove the spring, rubber sleeve, and the last washer.
6) Now find the piston's home position so that it retracts fully and flush with the caliper body.
7) Re-install the brake pads and pad spring
7) Use a brake spacer (like one used to reset hydraulic brakes) to keep them in the fully retracted position.
8) Reassemble

I hope this helps someone or the OP if he hasn't figured it out already. Cheers,

Eric

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cobba

· #13 · May 14, 2012 (Edited)

Kibble Fat said:
Basically, you can ignore all replies up until this one.

That's your opinion and your entitled to one I suppose, it doesn't mean that your correct though.

The problem you've encountered when putting the brake together after you've pulled it probably doesn't have anything to do with what the OP was experiencing with their brake.

1) Turn your outer pad adjuster and move the outer pad in towards the rotor
2) After you've done that, turn the outer pad adjuster as far as it will go in the opposite direction.
3) Does your outer pad retract fully after this has been done or do you need to squeeze the brake lever for this to happen ?

I don't think the OP actually had a problem, I think that it was a case of looking closely at how something worked and it didn't seem to work the way they thought that it should.

.

Isabis

· #14 · Nov 20, 2015

2

Old thread, but I think OP was having this problem, I'm having the same right now.
When I turn this knob counter-clockwise, the pad doesn't get further from from the rotor, it stays in the same position:

Bicycle part Bicycle accessory Bicycles--Equipment and supplies Bicycle Bicycle frame

It does get further away from rotor for like 5 clicks, but then it stops moving.

What is causing this problem is that this thing lost it's flexibility and it's not pushing the pad outwards strong enough:

Product Black Rolling Armrest

Just buy new pads or that thing if you can find it somewhere and problem will be fixed.

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cobba

· #15 · Nov 21, 2015

Isabis said:
Old thread, but I think OP was having this problem, I'm having the same right now.
When I turn this knob counter-clockwise, the pad doesn't get further from from the rotor, it stays in the same position.

You need to squeeze the brake lever to reset the outer pad after the outer pad dial is turned to move the pad away from the rotor, the pad will not automatically move away from the rotor after the dial is turned that way.

The pad spreader only keeps the pads pushed against the pressure feet, it is only made to do that.

Outer dial turns the foot screw.
The foot screw is screwed into the drive cam and pushes the outer pressure foot out of the drive cam when it is turned inwards.
The foot screw is not attached to the outer pressure foot, it will not pull the outer pressure foot back into the drive cam when it is turned outwards.
The outer pressure foot needs to be physically pushed back into the drive cam after the foot screw is turned outwards, this is done by squeezing the brake lever.

Line Font Circle Illustration Transmission part

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Reactions: 1

Isabis

· #16 · Nov 21, 2015

cobba said:
You need to squeeze the brake lever to reset the outer pad after the outer pad dial is turned to move the pad away from the rotor, the pad will not automatically move away from the rotor after the dial is turned that way.

The pad spreader only keeps the pads pushed against the pressure feet, it is only made to do that.

Outer dial turns the foot screw.
The foot screw is screwed into the drive cam and pushes the outer pressure foot out of the drive cam when it is turned inwards.
The foot screw is not attached to the outer pressure foot, it will not pull the outer pressure foot back into the drive cam when it is turned outwards.
The outer pressure foot needs to be physically pushed back into the drive cam after the foot screw is turned outwards, this is done by squeezing the brake lever.

View attachment 1030185

I was 99% sure my pad used to move away without a need to pull the brake lever so I went ahead and dismantled whole caliper in a hope to fix it. It was a good thing I did because there was a lot of residue left from worn out pads inside the caliper so I cleaned that all up and I also greased the friction surfaces a bit as well.
Only conclusion I had at the end, since everything was working fine after I inspected all the parts, is that the pad spreader lost it's flexibility and didn't have enough "strength" to push the pad outwards.
Guess I was wrong then.

cobba

· #17 · Nov 21, 2015

cobba said:
You need to squeeze the brake lever to reset the outer pad after the outer pad dial is turned to move the pad away from the rotor, the pad will not automatically move away from the rotor after the dial is turned that way.

Forgot to mention that the pads need to be in the caliper and the rotor needs to between the pads to do this.

Without the pads and rotor, the outboard pressure foot won't have anything to press against to push it back into the drive cam.

You could probably do this without the rotor by dialing the inner pad in fully so the 2 pads will be pushing against each other.

How the parts fit together.

Blue Yellow Text White Line

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849097

· #18 · Jan 19, 2020

My trouble is similar but caused by use, not adjustment. The outboard pressure foot spring clip failed due to braking torque and the pressure foot could not be pushed back as the clip was out of the groove and made the foot too large diameter. I removed the clip as the groove could not retain it, and now it retracts only with the force of the brake clip. How can I source a new pressure foot? My BB7 complete price was $45. I'm liking the Tektro Gemini using the old Shimano standard pads, and similar to old Deore and they go for that now. The BB7 appears to be too complex to maintain.

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