Tandem Cycling - Braking News

Greetings all-

Finally had enough of the intermittent squealing and squalling of the Avid V-brakes on our Co-Mo Cappuccino. Even with the use of Da Vinci brake stiffeners, the noise was making my stoker nervous about being able to stop. I ordered an Avid BB-7 kit with 203mm rotor from Mark Johnson at Precision Tandems. It went on with no problems and that took care of half of the noise problem. Turning my attention to the front of the bike, I pulled the fork out, jigged it up in my drill press, and using the threaded fender boss as a guide, drilled through to the front to mount a caliper brake. I mounted an Ultegra caliper, put the wheel in the fork, and lo and behold-it works! I had to chamfer the top edge of the brake pads as they were very close to the tire. I got everything adjusted and we took in out for a spin yesterday afternoon. It's quiet! It stops!

I've got some new road brake levers on the way to replace the Dia Compe 287-V levers that are on the bike now, so that should help a bit. I'll probably replace the front caliper with a 'long' reach unit in the near future. All in all, a 100 % successful project. Everything went smoothly on the conversion. I'm happy, stoker is happy, the disc brake looks cool. What's not to like?

George Handy in sunny and cool Arlington Texas, where hurricane Ike was pretty much a non-event in our area.

Yep, our Avid V-brakes on a Co-Mo Mocha also squeak and not provide as much braking as I would like unless I really apply some force.

Note that I have no idea of the answer to this question.

Is the crown of a canti fork designed to take the load of a caliper brake ?

The problem with the Avid V brakes is that they aren't secured very well on the brake posts. Ours moved quite a bit even when secured as tight as they could go. With all that play - you'll get squealing. I put on some XTR Vbrakes which solved our problem and promptly threw the Avids in the circular file.

George:
Silence is golden!
Stopping is essential!
Pedal on TWOgether!
Rudy and Kay/zonatandem

I've got some new road brake levers on the way to replace the Dia Compe 287-V levers that are on the bike now, so that should help a bit. I'll probably replace the front caliper with a 'long' reach unit in the near future.

IMO, one of the big advantages of disc brakes is how (relatively) little hand pressure it takes to slow down. To realize the benefit, however, you must have compatible levers. Standard road levers should feel much better with both road BB-7 brakes and dual-pivot calipers.

Enjoy!

Dave

The problem with the Avid V brakes is that they aren't secured very well on the brake posts. Ours moved quite a bit even when secured as tight as they could go. With all that play - you'll get squealing. I put on some XTR Vbrakes which solved our problem and promptly threw the Avids in the circular file.i pulled the avid arch rivals off my cross bike and put them on the tandem with travel agents after i went down the first hill with the mini v-brakes. but the avids always squealed. i kept adjusting the pads but couldn't get it to go away. i also changed the pads and that didn't help much either. finally after cleaning the rims and pads the noise would go away, but only for a ride or two 'til the rims got dirty again.

do you think the movement is from the difference in the o.d. of the post and the i.d. of the brake? or from the bolt not holding the brake on tight enough? i also noticed that one for the front pads was not very snug in the pad holder, i have swapped it for another brake pad that fits tighter in the holder but haven't had a chance to ride it yet to see of it helps.

We've got Avid V brakes on our Co-Pilot. We have bar end shifters and Dia-Compe 287V brake levers so no Travel Agents. I have had squealing problems in the past but as on the above post, cleaning the rims solved the problem. Once rubber transfers from the pads to the rims, you get rubber on rubber and it squeals. Cleaning the rims with a ScotchBrite pad works well.

The only time braking "power" was a problem was on steep descents with tight switchbacks where the rims heat up. This would be a problem with any rim brake. I don't know how disc brakes respond to dumping this much heat into them.

I'm a bit surprised to hear of the squealing issues with the Avid V's. Late last year we converted our older C'dale from Canti's to Avid SD 7's V brakes w/travel agents along with STI brifters. They have performed outstanding from day one with little setup effort. No squealing in the least and quite good stoping power. They came with CW2 pads. We live in a very hilly area and use them pretty hard at times. We've got near 2000 miles on them so far.
FWIW..I had Avid Shorty 4's canti's on the front of my '07 cross bike with an Easton EC70 carbon fork and those things squealed everytime I even thought about using them. Tried a million different setups to get then to quiet down but nothing worked. So when I took the old Shimano canti's off the C'dale I put them on the cross bike and what do you know...not even the slightest hint of a sound, perfectly quiet and still good breaking. I'm not smart enough to know why they worked but I'll take it!
Bill J

Cleaning the rims with rubbing alcohol solved the problem for us.