Avid BB7 road disc brakes question

[nonsleepingjon]

I stopped in to an LBS over the weekend and fooled around with a few 'cross bikes that had avid bb7 road disc brakes (cable actuated, I think tiagra levers). On the bikes I tried, I could pull the brake lever almost all the way to the handlebar. The stopping power didn't feel as strong as the next bike over with cantilever brakes. Is that normal? This wasn't a scientific test or anything, but I thought that I'd be more impressed with the disc brakes.

On the mountain bikes I've tried disc brakes are simply amazing. I don't know if it was the road levers, or the cable vs. hydraulic lines, poor set up, or something else, but the road version just didn't impress me the way I thought it would.

[Sledgehammer03]

There are little red knobs on the inside and outside of each brake. You simply turn these to push the brake pad closer to the disc. The closer the pad, the less pull required. as the pad wears, of course, you have to adjust. When adjusted properly, you have great control and great stopping power. That's my experience anyway.

[James@GearReview]

In addition to what Sledgehammer said, disc brakes require multiple stops to bed-in the pads to the rotors. Out of the gate, the brakes are ok, but after bedding them in, they are excellent.

[Wookiebiker]

As others have mentioned you have to perform multiple hard stops to break the pads/rotors in. When you first try them they are super weak in performance. After about 30 hard stops the power starts to come on and they work much better than normal rim brakes.

I run the Avids on my road bike and they are simply awesome compared to rim brakes. I have rim brakes on my Tri/TT bike and there is no comparison between the two.....The Avids just need to be broken in first.

[nonsleepingjon]

Originally Posted by Wookiebiker

As others have mentioned you have to perform multiple hard stops to break the pads/rotors in. When you first try them they are super weak in performance. After about 30 hard stops the power starts to come on and they work much better than normal rim brakes.

I run the Avids on my road bike and they are simply awesome compared to rim brakes. I have rim brakes on my Tri/TT bike and there is no comparison between the two.....The Avids just need to be broken in first.

I figure they weren't "worn in" yet on a new bike, but it was strange that I could pull the lever so far - is that how it is on yours as well? I did try adjusting the red knobs, but it didn't seem to make much difference in lever movement.

[Wookiebiker]

Originally Posted by nonsleepingjon

I figure they weren't "worn in" yet on a new bike, but it was strange that I could pull the lever so far - is that how it is on yours as well? I did try adjusting the red knobs, but it didn't seem to make much difference in lever movement.

Yes....The Avid BB7 Road Discs don't have the same lever feel that they do on MTB's. The levers are a bit "mushier" than they are on MTB's. Even when set up with super close tolerances I can pull the levers back to the handlebar.

However, the brakes have enough power that I can set up some room between the pads and still have excellent stopping power (much better than on my rim brake equipped road bikes).

I do wish there was some lever adjustment available for these brakes to increase the leverage just a bit so the brakes would feel a bit more solid. However, I never have to worry about my forearms getting tired from braking so hard...One finger is all it really takes.

[Eben]

I had this same problem setting up avid discs on my light touring bike, I'm using Campy stuff. Just about went crazy trying to figure out how to keep the lever action from feeling like crap, here's what worked for me.

Even after setting everything up per the Avid manual, caliper alignment is key as are pad position. cable routing, and spring tension, the levers would still just about bottom out. This has nothing to do with the brakes bedding in. They absolutely do get more powerful after a short while but that doesn't fix poor lever feel.

The thing that finally made the brakes live up to their potential was to change the position of the caliper arm in relation to the cable. Simply put, move the caliper arm a short distance along it's path of travel before tightening the brake cable.

From what I can tell, the brake pads have an increasing rate of travel as the arm moves along its arc. if you clamp the arm to the cable when the caliper arm is fully open you have to pull your lever a good way before the pad moves much at all, resulting in a really spongy feel.

If you set up the pads really close you can get a decent feel but they will proabably rub. On the other hand if you more the caliper arm part of the way through it's travel before clamping the cable, your initial pull of the lever will move the pad at a greater rate. Bingo, great lever feel and no rubbing!

[nonsleepingjon]

Originally Posted by Eben

The thing that finally made the brakes live up to their potential was to change the position of the caliper arm in relation to the cable. Simply put, move the caliper arm a short distance along it's path of travel before tightening the brake cable.

From what I can tell, the brake pads have an increasing rate of travel as the arm moves along its arc. if you clamp the arm to the cable when the caliper arm is fully open you have to pull your lever a good way before the pad moves much at all, resulting in a really spongy feel.

If you set up the pads really close you can get a decent feel but they will proabably rub. On the other hand if you more the caliper arm part of the way through it's travel before clamping the cable, your initial pull of the lever will move the pad at a greater rate. Bingo, great lever feel and no rubbing!

What about using a travel agent or similar device that increases cable pull? Or have I wandered in to the land of crazy talk?

[Wookiebiker]

Originally Posted by Eben

I had this same problem setting up avid discs on my light touring bike, I'm using Campy stuff. Just about went crazy trying to figure out how to keep the lever action from feeling like crap, here's what worked for me.

Even after setting everything up per the Avid manual, caliper alignment is key as are pad position. cable routing, and spring tension, the levers would still just about bottom out. This has nothing to do with the brakes bedding in. They absolutely do get more powerful after a short while but that doesn't fix poor lever feel.

The thing that finally made the brakes live up to their potential was to change the position of the caliper arm in relation to the cable. Simply put, move the caliper arm a short distance along it's path of travel before tightening the brake cable.

From what I can tell, the brake pads have an increasing rate of travel as the arm moves along its arc. if you clamp the arm to the cable when the caliper arm is fully open you have to pull your lever a good way before the pad moves much at all, resulting in a really spongy feel.

If you set up the pads really close you can get a decent feel but they will proabably rub. On the other hand if you more the caliper arm part of the way through it's travel before clamping the cable, your initial pull of the lever will move the pad at a greater rate. Bingo, great lever feel and no rubbing!

Thanks for the tip....

I went to my garage last night, moved the lever arm up on the brakes and it took a lot of the lever mushyness away. Much more solid lever feel and the solid braking remains.

[J .]

I'll hijack this thread for a bit, one question concerning bb-7 roads..

Just got my new bike from the LBS where it was put together, and as I arrived home I noticed there's a slight rub going on in the rear brake. I took the manual that came with the brakes and did what it said (and what this video says: http://www.youtube.com/watch?v=x1kezXQVnLY), ie. loosened the screws that hold the caliper in place, tightened the pads in the order mentioned in the manual and re-tightened the caliper into it's place. It helped somewhat, but I'm still having constant, slight rub even thou the outer pad is in it's full out position (all clicks counterclockwise). The wheel rolls couple of rounds but I can hear and see that the outermost pad is touching the disc. Any ideas on how to fix this thing?

Thanks!

[Wookiebiker]

Originally Posted by J .

I'll hijack this thread for a bit, one question concerning bb-7 roads..

Just got my new bike from the LBS where it was put together, and as I arrived home I noticed there's a slight rub going on in the rear brake. I took the manual that came with the brakes and did what it said (and what this video says: http://www.youtube.com/watch?v=x1kezXQVnLY), ie. loosened the screws that hold the caliper in place, tightened the pads in the order mentioned in the manual and re-tightened the caliper into it's place. It helped somewhat, but I'm still having constant, slight rub even thou the outer pad is in it's full out position (all clicks counterclockwise). The wheel rolls couple of rounds but I can hear and see that the outermost pad is touching the disc. Any ideas on how to fix this thing?

Thanks!

Sounds like you could have a slightly bent rotor, which, depending on how far out of true it is can be bent back straight....especially if you have a big bench vice. The tolerances are so close when using road levers that a rotor that's just slightly out of true can make a difference with brake rub.

With that said...a little rub isn't going to make a difference other than annoy you a bit...which can be frustrating after a while.