Bakerboy

Anyone know if there is a v-brake or cantilever brake that will work on both 26 and 700 c wheels. I have an older Burley tandem with 26 wheels but can fit 700c wheels. Brake posts were built for 26 in wheels but would like to be able to use it on road with 700 c wheels.

fietsbob

No.. rim radius is far to different.. just buy different tires for street - road use .

700c aka 622 rim diameter halved is 311, 26" wheel aka 559 rim halved is 279.5mm
so difference in radius is 31.5mmm almost an inch and a quarter. difference..

if there were holes in the fork crown and the chainstay bridge you could fit a different brake,
(needing different levers)
for the bigger 700c wheel

drum brake hubs bypass using rim brakes entirely Your wheels then can be retrofitted..
where disc brakes need frame fittings for mounting them. welded on.


there are some nice comfortable fat 26" tires for performance riding expectations.



...

Rick

Paul Component Engineering makes the Motolite V brake and it is designed just for your purpose.https://www.paulcomp.com/shop/components/motolite/

fietsbob

leverage , MA, will suck by moving the pads so far from the pivot ... so you'd have to squeeze it a lot harder..
might still have to change brake levers..

V brake levers have low MA, now caliper will also have a lot lower MA as well




...

Rick

The difference at the brake is about 1 1/4 inch or 63mm.

fietsbob

and that is a significant reduction in mechanical advantage , in what is a class 2 lever ..

It's more like a wheelbarrow you have a load moved a lot closer to the handles having formerly been closer to the wheel.


1.25" = 31.75mm

for 63 you are using a diameter number.. 2X radius difference, gets your 63

bottom half of wheel, doesn't count in brake reach..





....

nfmisso

WOW, a V brake with the most difficult features of a traditional canti, at 10X the price........

Nice looking, but I would not want them on a bike I ride all the time.

79pmooney

Two ideas: 1) have made canti levers that are sized up, both higher and with substantially longer arms. Run them with long-pull V-brake levers. Granted, not easy, requiring both design work and fabrication. And 2) are there drop-bolts for Mafac Racer style centerpulls. Seems to me you could make a long drop-bolt that had a rear leg that came back, then up to the rear of the fork crown to stiffen the assembly.

A challenge, but not un-solveable. Easy? Maybe not. If I had your bike, I just might try. I am after all the guy who set his old custom up to ride fix gear with three compete sets of drivetrains for real mountain days, 46-12, 44-17 and 36-21 (and can go down to 36-24). A lot of work, both design and execution and it runs really well! If you figure this out, you could be on to something.

Ben

Rick

I have a 15 year old set of these brakes on my sons new touring bicycle. They are easy to setup. They have no play in the pivots like those other brakes that you claim are 10 times lower the price. They are lighter and have no perceptible flex either. The best thing about them is they would work in this situation and the other v brakes would not. Post another solution that will allow the 700c wheels to have brakes on a bicycle designed for 26" wheels.

fietsbob

Asia vs California costs of doing business ..

HTupolev

1 1/4 inches is an enormous change. In most setups it will roughly double the length of the brake pad's "lever", which will halve the power of the brakes.