How to dial-in Avid BB5 mechanical disc brakes

October 30th, 2006 by Tim Grahl

The Avid BB5 mechanical disc brakes have just one pad adjustment knob as opposed to the Avid BB7 which allow you to adjust both pads.

This how-to is for the Avid BB5 and is the easiest, most consistent way I’ve found to dial-in these brakes.

Tools you’ll need:

5mm Hex wrench
spare paper or biz card

Optional:

P-Handled T25 Torx Wrench

And the steps…

Use the 5mm hex wrench to loosen the bolts that connect the brake to the frame. Don’t pull the bolts completely out, however make sure there is enough space so you can move the caliper easily.

Put a spacer between the rotor and fixed brake pad. This is the pad that’s farthest away from the wheel.
In the picture I used a few sheets of thin paper. A buddy of mine has used a business card as well. Basically you just need something that will provide a small amount of space between the rotor and stationary brake pad.

Tighten down the pad adjustment knob by turning it clockwise. You can do this by hand, however it’s easier to use the P-handled T25 torx wrench. Make sure you tighten the knob all the way down. Don’t overtighten and break anything, however make sure it’s really snug.

Tighten the bolts that attach the brake to the frame using the 5mm hex wrench.

Loosen the pad adjustment knob all the way and carefully remove the paper spacer.
Tighten the pad adjustment knob until you have optimal stopping power. Be sure to test it out by spinning the wheel by hand and pulling the brake before you try to ride again.

So what did we do?

One of the hardest things about installing the Avid BB5 caliper on the frame is making sure it is in line with the rotor and that there is the right amount of space between the rotor and stationary brake pad. Adding the paper spacer ensures there is good clearance between the rotor and brake pad. By tightening the pad adjustment knob all the way down with the caliper bolts loosed you are making sure the pad and rotor are lined up correctly.

Have any questions or thoughts? Leave them in the comments.

33 Responses to “How to dial-in Avid BB5 mechanical disc brakes”

RSS & Trackback

1 Pablo Montero on Dec 30th, 2006 at 5:12 am

Hello,

It looks like you didn´t install the CPS washers between the calipers and the brackets. This is critical as it is the CPS hardware which allows the caliper to be properly aligned with the rotor. Not having the CPS washers installed also causes the caliper to bite to low on the rotor which may lead to decreased brake performance.

You can find the instructions for proper installation/tuning in the following document:

http://www.sram.com/_media/techdocs/2006_BB5and7_English.pdf

Regards,

Pablo.
2 swo on Jan 30th, 2007 at 6:34 pm

Thanx!

This bit of info. was truly helpful. I’m running smooth again.
3 TimC on Jul 6th, 2007 at 4:26 pm

Brilliant! Worked like nothing else had, thanks so much. Now if I can just figure out if the warp in my rotors is enough to warrant replacing them.
4 Me on Jul 27th, 2007 at 12:50 pm

I used a folded 3×5 card, nice because you can tear it into a longer strip which makes it easier to get between the pad and rotor. Who needs them BB7s?
5 BIG on Aug 7th, 2007 at 2:32 pm

Thanks a lot Tim! They were mis-aligned and squelling, after going thru the owner’s manual intructions and yours, I decided yours made more sense and to try it first. It worked! It now has a smooth clean accurate feel without drag. I used a plastic card slightly thinner than a CC, it was a bit difficult inserting in the rear caliper though, may try something thinner next time.
6 BIG on Aug 7th, 2007 at 8:57 pm

Thought I’d include the owner’s manual instructions for camparison…

Align The Caliper
A. Use your fingers or a Torx® wrench to turn the inboard pad adjustment knob
clockwise until the rotor is centered in the caliper. This positions the pads for
the next step in the installation.
B. Make sure the CPS bolts are loose enough for the caliper to move freely.
C. Squeeze the brake lever to compress the brake pads firmly on the rotor.
D. While still holding the brake lever, tighten the CPS bolts. Once they are tight you can let go of the lever.

Adjust The Pads
Back the adjustment knob off (counterclockwise) until the rotor spins freely.
Now you can dial the pad in or out until you find the brake action you prefer
(make sure, of course, that there’s no drag on the rotor). If you can’t seem to
get the feel you like, or the rotor is dragging, repeat step 5.
7 Isaac on Sep 26th, 2007 at 5:19 pm

Wow, that worked better than expected. I was using the rear too much, and it finally retaliated after a drenched, sandy trip at Chilhowee system in TN. Thanks so much for the quick fix, had no problems whatsoever and I’m stopping on a dime again!
8 Tydog on Oct 8th, 2007 at 1:26 am

One thing I noticed from the SRAM instructions compared to yours is that SRAM says several times to make sure the torque arm(I assume they are speaking of the break actuator arm the brake cable is connected to) is all the way out until you need to adjust it for pad wear. From your pic’s I see the the torque arm is not all the way out. I found that I could not ge enough adjustment in the brake until I moved the torque arm close to the barrel adjuster and then tightened the brake cable. That is also what it looks like in your pic. Any comments?
9 nato on Dec 21st, 2007 at 6:34 pm

Don’t leave the “torque arm” all the way out. the brakes will feel spongy. I choke up on mine quite a bit.

Basically, at the point of maximum braking, you want the cable to be pulling relatively straight. the way it’s set up in the pictures is pretty much perfect.

I’ve dealt more with the Bb7s, which IMO are a better brake only because the throw of the caliper arm is what makes it feel like crap, or what makes it feel as good as hydraulic brakes. Being able to adjust the throw and the pad positions independently, you can dial them in to feeling as good or better than much more expensive brakes.
10 Scott on Jan 12th, 2008 at 2:13 am

Great tip! Worked flawlessly. Saved me a trip to the bike shop to perfectly dial in teh brakes. Thanks.
11 Dan N on Feb 10th, 2008 at 9:47 pm

Excellent!!!

I have an 08 RockHopper with BB5’s and I had NEVER been satisfied with the front brake’s performance (never stopped well, heading down a hill, gripping the brake lever full force would still only bring me to a stop slowly and really squeaked). Of course, the rear just skids if I’m not careful.

I’ve had it into the shop several times with the tech telling me there was nothing wrong he could see (but he never actually rode it to try).

Your above instructions took me (a bike beginner) less than five minutes, armed only with a 5mm Allen wrench and a sacrificial business card. This bike stops flawlessly now. I almost went over the bars the first time–it’s going to take some getting used to.

Thanks!
12 Adi on Feb 28th, 2008 at 4:59 am

Fantastic! I had my mechanical breaks stollen. Just replaced these with Avid BB5’s, and they were not fitted well at the store. They’ve been making a lot of noise.

I’ve never done this type of fix before. Just applied the changes you described - took less than 5 minutes, and the bike is now very smooth - like new - and the breaks are strong.
Good tips and clearly described.

Cheers,

Adi (London, England)
13 Robert (Carlsbad, CA) on Apr 12th, 2008 at 5:01 pm

Thanks for the good tip. Just upgraded the front brake of my Jamis Exile from the Aavid Single Digit 3 to a BB5.
14 John H on Apr 16th, 2008 at 8:36 pm

This was a big help. Thanks for the super easy fix. It really suck when the bike shop can’t even do something that easy.
Thanks again
15 scott silvers on Apr 21st, 2008 at 1:04 pm

Attention BB5 folks - you can pop off the red cap on the outboard “non-adjustable” pad side of the caliper. This exposes a nut head. This is actually the pad adjuster for the “non-adjustable” pad! I got my trusty dremel out, slapped a thin cutting wheel [wear eye protection pleez], and cut a flat head screwdriver sized notch in the bolt head.

This mod turns your BB5 into a fully functional BB7 brake - albeit, the pads are still round, not square like the 7’s…..and you also have the benefit of yet another barrel adjuster on the caliper for more cable slack tuning options……

I did this mod years ago for my singlespeed, and it works superbly - no need to up-spend for BB7’s if you do this mod.
16 martinjy on Jun 6th, 2008 at 10:33 pm

I found these instructions really easy to follow. Thanks heaps for posting them in this way.
17 Chrystal on Jun 22nd, 2008 at 2:54 am

Thanks so much for the tips and the clear pictures. The squeaking in my brakes was driving me crazy and a mechanic said they were just going to be that way. With 3 business cards on the fixed side of the front brake and one business card on the fixed side and one on the adjustable side for the back brake they are now both working with full stopping power and no squeak. My ears thank you!
18 Eric on Jul 30th, 2008 at 6:25 pm

I tried this and it has helped my front brakes, but my back brakes are barely even slowing me down, I don’t know what else to try. It seems like it is lined up just like my front one is. But it is like it has no power and it squeeks like a mother. I’m no expert, but just looking at it there seems to be nothing wrong. I have only had this bike for a year so I don’t think I would need knew brake pads. Before I took off my back wheel to put the knew tires on it worked perfectly. But, for some reason it isn’t working anymore. Plz help
19 Etienne on Oct 19th, 2008 at 4:07 pm

Wow.. this tip is excellent.
I took half a day to try to adjust my bb5 with the sram document. By using this method, I adjusted my front and rear brakes in almost 10 minutes.
I’ll definitively remember this trick for the future.
Thanks
20 Coops on Apr 7th, 2009 at 2:57 pm

Hi. Fantastic! At last I know how to do this. Thanks very much.
21 Jondo on Jun 23rd, 2009 at 8:43 am

Thanks for a great procedure - this fixed up my BB5 squeaking/grinding noises no problem at all - they had been doing it since new on my Haro Mary SS, very annoying. Now they have nearly as good a feel as my Juicy 5’s my other bike and are almost completely silent.

Top stuff.
22 mitchell on Oct 10th, 2009 at 1:24 pm

unbelievable!!! can’t thank you enough.
23 Saibal on Jan 5th, 2010 at 10:11 am

Hi,
I live in a country where BB5 disc brakes spares are unavailable & very hard to get. I have tried to adjust the front brakes using the method but the squeeky noise on the front brake is still there. I have noticed that the front disc is not straight and seem to wobble slightly when the wheel is rotated, therefore spacing with business card dosen’t help, as while riding, the disc rubs on the pads no matter how much the spaceing is adjusted. The bike shop guy asked me to clean the disc with alcohol, which I did without letting the alcohol on the pads, just to make the front brakes slip even more. He also asked me to take off the pads and use #200 sand paper to rub the pads flat and refit. Please advice me. Thanks. Saibal
24 jokermtb on Jan 5th, 2010 at 11:30 am

Saibal - your rotor disc is bent in one, or two, or three places - or possibly warped. Park Tool make a wonderful rotor truing tool, Dt-2 Disc Brake Rotor Truing Fork, $10-15. It’s one of those tools you think you’d never need or want, but once you use it you find yourself keeping your rotors perfect - because it’s so easy to do with this tool. But, you can true your rotor with any cheap adjustable crescent-style wrench. Just set it to the width of the rotor and gently bend the rotor to one side or the other and give the wheel a spin. As the wheel spins, look down into the gap where the disc rotor goes between the pads and see/hear when it rubs - identify that spot and bend it the opposite way - spin again and check - repeat til satisfied. Chances are, you’ll have to bend the rotor in various spots, to get rid of the scraping against the caliper pads, but you’ll eventually get it as straight as humanly possible. Good luk!
25 Saibal on Jan 11th, 2010 at 3:18 am

Hi, thanks for your advice. I have now straighten the disc and there is a very very slight warp now. I have adjusted the pads like adviced by placing the thin sheets of paper. I have also managed to take out the pads, rub it on very fine sand paper, take off the black deposite on the surface of the pads, cleaned the rubbing surface. Made sure that the thickness of the pad is same all through the surface of the pad that rubs against the dics while breaking. The improvement is there on the rear brakes but only slightly on the front brakes . I also noted that the front pads have worn out to about 50% thikness. Does this effect the performance of the breaking, even after adjusting the brake calipers? Thanks
26 jokermtb on Jan 11th, 2010 at 6:22 pm

Seems that your front pads are not only worn [getting there], but still contaminated - sometimes oils will “soak” into the porous pad material. I’d suggest swapping your rear pads to the front, and your front pads to your rear , and see if there’s a difference when located in the swapped caliper locations. I bet there will be. Pads usually wear out in the front first, because they’re used more. Besides you get more stopping power on the front, might as well put the better condition pads there.
27 Saibal on Jan 15th, 2010 at 10:41 am

Hi !! Thanks for you advice. I have now swaped the rear brake pads to the front and the front brake pads to the rear. The results are as follows. The front braking power has increased from 10% to 85% and the rear breaking has gone down from 95% (wheel locking type) to 20% just to give you an idea. I have now got a fresh problem, as I adjust the pads to the to get the above breaking power, the pads rub slightly againts the brake disc, both rear and front. If I loosen it a bit so that the pads don’t rub, the breaking power goes down by quite a bit. Any advice???
28 jokermtb on Jan 15th, 2010 at 12:43 pm

You need to re-center the caliper. When you move pads or put new ones in, you must readjust the entire caliper. I’m assuming you tried turning the red adjuster knobs on each side of the caliper to no avail, which would indicate that you need to do some caliper re-centering [which is easy]
29 Saibal on Jan 15th, 2010 at 10:57 pm

Hi thanks for the mail. How do I re-centre the caliper? I guess the pads have worn out to unequal thickness. Please note that when I refitted the pads after swaping them, I re-installed the calipers by the method shown on the site, but braking power was not there. After re-insattling the calipers by placing thin paper etc between the disc and pads as shown & finding no braking power, when the brake lever is pressed, I found the pads don’t move far enough to hold the disc with the force required. I than turned the red knob slowly a little at a time and the cable tensioning adjuster on the brake cable to get to the desired breaking power. I am now confused as to what should be the re-centring method for the calipers. Thanks
30 jokermtb on Jan 16th, 2010 at 10:30 am

I usually adjust my brakes a different way. With new pads in, and the caliper mounting bolts loose, I’ll turn the two red pad adjusters in til the pads contact the rim. I’ll spin the wheel around - very difficult at this point - and see if I can turn the pads adjusters even tighter.

Then, apply the brake with your hand on the brake lever - lock it up. With your hand keeping a firm grip on the brake lever, just tighten up the two caliper mounting bolts again.

Keep in mind [when looking down and thru the caliper] I usually tighten the pads up so that the inboard pad is barely peeking over the edge of the caliper body [enough so the disc doesn't touch the caliper body!], while you can see a good bit of the outboard pad - this gives you a lot of adjustability for later.

So, now all you want to do is back off of the outboard pad, to eliminate any scrapes, and back off a touch on the inboard pad to eliminate any scraping.

Low power brakes usually mean that the caliper actuator arm is swinging around too far - you want it to arc thru it’s motion faster. It goes against popular methods, but moving the caliper actuator arm off it’s “stop” and anchoring it higher up on the cable works wonders - it’s like your preloading the brake pull without acutally applying the brakes. I’ve found this helps when you use the hand lever and the brake just doesn’t pull hard on the pads - which means your cable is too long. Loosen up the caliper arm cable locknut, and while keeping the cable still, slide the arm up 5mm and lock it down again….it will pull less cable [which makes pad adjustment and no bent disc critical], but it will be much firmer and stronger.
31 Saibal on Jan 16th, 2010 at 11:12 am

Hi Sorry for the messup. I have sent you a mail on the wrong address. The following is the question I have asked & am not in any hurry. Please look into the questions and let me on it when you can find a moment. Thanks for your patience with me….
Hi!! Thanks a lot for the information. I have got a few questions, I have a BB5 caliper and this has only one red pad adjuster near the wheel & not two. I would also want to know which one is the inboard pad, the one with the moving arm or the one with the stationary adjusting wheel side? Which one is the outboard pad. Please also note that my disc is a bent and does show a slight wabble while turning although I have tried to straighten it as much as possible. Am also left with old worn out pads and not new ones. The front pad is about 60% of original and the rear is 40% of original thickness. Am sure it is a lot to ask to get perfect breaking from parts that is not upto the standerd or new but that is where your experience comes in which I don’t have.
32 jokermtb on Jan 16th, 2010 at 1:25 pm

the inboard pad is the one closest to the wheel’s hub [or, center of the bike]. The outside pad is the one furthest from the hub. On a BB5, only the “inside” pad is adjustable with the turn wheel adjuster. to adjust the outside pad, you have to use the threaded adjuster on the cable to move the pad in/out….but, there’s another option!

Notice the red cap on the outside of the bb5? Earlier in this thread, I mentioned modding a bb5 to be adjustable for the outside pad [like a bb7]

“Attention BB5 folks - you can pop off the red cap on the outboard “non-adjustable” pad side of the caliper. This exposes a nut head. This is actually the pad adjuster for the “non-adjustable” pad! I got my trusty dremel out, slapped a thin cutting wheel [wear eye protection pleez], and cut a flat head screwdriver sized notch in the bolt head.

This mod turns your BB5 into a fully functional BB7 brake - albeit, the pads are still round, not square like the 7’s…..and you also have the benefit of yet another barrel adjuster on the caliper for more cable slack tuning options……

I did this mod years ago for my singlespeed, and it works superbly - no need to up-spend for BB7’s if you do this mod.”

And, all disc brake rotors will have some degree of wobble/bent-ness…It’s impossible to avoid. You just have to keep on top of it and not let it get too out of control. Good thing is, Avid mech’s are very adjustable, and there’s all sorts of combos you can try…experiment, you’ll learn a lot.
33 Dan on Jan 21st, 2010 at 3:42 pm

This was very helpful! The Avid 5’s came with my new pedal/electric bike (A2B). I’ve now got them dialed in thanks to the OP’s post and the input by others here. No trip to the bike shop necessary.

DW

How to dial-in Avid BB5 mechanical disc brakes

33 Responses to “How to dial-in Avid BB5 mechanical disc brakes”

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