Take the 2-minute tour ×
Bicycles Stack Exchange is a question and answer site for people who build and repair bicycles, people who train cycling, or commute on bicycles. It's 100% free, no registration required.

I've discovered the brakes on my Bike Friday Tikit don't allow for enough clearance to run Schwalbe Marathon tires. The bike - a folding bike with 16" rims - ships with Kojak treadless tires. It looks like, as long as I have the existing caliper brakes - Tektro R530 brakes - I won't be able to run anything more robust than the Kojaks.

Brake removed from the bike:
Tektro R530 brake

Brake on the bike, showing the tire:
Tektro R530 brake on a Bike Friday Tikit

There isn't any way to mount these brakes differently, and the frame only has braze-ons for these brakes. A smaller tire or a smaller brake are really my only options, short of mounting the rims farther out - a bit of a kludgey solution, I think.

While I'm open to simply finding a smaller tire, I would much prefer to run Marthon tires as I'd like to use this bike for some light touring.

My question is: Are there caliper brakes with more tire clearance I could mount on this bike? What should I look for in these brakes? Will new brakes require me to change my brake levers? (I'm using Tektro RX 4.1 reverse levers.)

share|improve this question
    
The most obvious fix would be to get new studs brazed on for cantilever or V brakes. I would assume that one can find side-pull calipers with more width, but you're limited in depth by the position of the existing stud. (Though you could consider the expedient of simply grinding down the existing calipers, or a single-pivot unit might give you a hair more clearance.) –  Daniel R Hicks Oct 9 '11 at 21:04
    
An odd "fix" comes to mind: Get a machine shop to make up a "U" piece with a hole at the base of the "U" to fit the existing stud, and studs on the legs of the "U" to accommodate cantis or Vs. Would take some experimentation, I'm guessing -- not clear, eg, whether the thing would tend to be self-centering or whether you'd have to rigidly fasten it somehow. –  Daniel R Hicks Oct 10 '11 at 1:35
add comment

1 Answer 1

up vote 3 down vote accepted

This is an interesting question, well suited to this site! The problem is a common one for touring cyclists wanting a 25-32mm tyre and mudguard, where the solution is to 'get a bike with cantilever bosses'. You have a compound problem of short reach, a measurement you could do with measuring.

The dual-pivot brake doesn't offer a lot of tyre clearance, but do you need dual pivot anyway? Campagnolo groupsets have the dual pivot on the front but single pivot on the back, here is the affodable-style Veloce option:

enter image description here

A high-end Campagnolo brake may just about work for you and be a classy addition to the bike, giving vastly improved stopping power over the Tektro efforts, but you still might struggle to get a big tyre on there.

You can mitigate against that by using a slightly thinner 16 * 1.35" Marathon Plus tyre - this will give you more puncture protection than the 16 * 1.75 Marathon and would be my preferred option. Note that the 16 * 1.35 Marathon will have a lower profile than the 16 * 1.35 Marathon Plus, so more room can be gained at the expense of puncture protection.

Also worth investigating are late 1980's era Weinmann and Dia-Compe side-pulls of the short-reach flavour. These will not have the stopping power of today's side-pulls, however, how much stopping power do you need to lock up the rear wheel? A bit of flex won't be the end of the world on the back brake, and these early brakes can be had for a good price. The shape of the arms on these brakes did allow for a reasonably fat tyre, the only real problem is getting the recessed allen key rather than bolt attachment. That said, the main bolt on the Weinmann brakes can be interchanged as they were available to suit recessed, Allen key fitting. Here are some Weinmann 500's, from centuries ago,but with compelling tyre clearance:

enter image description here

These were available in black. Another beauty is the 605. This one does not have the hex-bolt exposed to aid centering, but I don't think you can beat the combination of short reach and tyre clearance:

enter image description here

Ebay is going to be your friend here, another option you might want to investigate is center-pull. Sticking with Weinmann, here is the 999, seemingly available in short reach flavour:

enter image description here

You could run it U-brake style with some cable stop for the outer bolted onto the underside of the b/b, or investigate if that sort of thing is possible...

share|improve this answer
    
Bike Friday mentioned single-pivot brakes as a possible option, although only in a general way. If I go for a used single pivot like the Weinmann, will I have any trouble getting replacement brake pads? Do these have any alignment troubles over dual-pivot brakes? –  Neil Fein Oct 10 '11 at 1:55
    
Pads are no problem, the attachment bolt can be with early Weinmann brakes, however these can be mixed and matched as the bolt was the same on the brake side in the middle part that holds the spring and they did do some allen key recessed models. –  ʍǝɥʇɐɯ Oct 10 '11 at 7:07
    
I've spoken to my dealer and the manufacturer, and they feel that I could get more clearance like this, but not enough for comfort. Will be sticking with skinny tires, but this will doubtless help someone else. Thanks for the answer, and the great information! –  Neil Fein Oct 11 '11 at 17:25
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.