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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 Marathon 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.)

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  • 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, 2011 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, 2011 at 1:35
  • From the picture it looks like the pads are not sufficiently curved to match the curvature of your wheel diameter. This could be half your problem. Find pads that are more curved.
    – Kaz
    Oct 29, 2014 at 22:27
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    @Criggie Oddly enough, I'm still working with this problem. I got a flat and couldn't afford another Kojak, so I put the bike aside for a few years. Recently, I got a pair of Marathon Racers, which demonstrated that my rear brake needs to be replaced. Googling the problem brought me to this question! (continued)
    – Goodbye Stack Exchange
    Apr 4, 2019 at 13:11
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    ...As I indicated below, I stuck with skinny tires in 2011 but now am revisiting the problem. My shop is investigating brakes with better clearance (since my rear brake needs to be swapped out anyway). I'll update more fully once we have this worked out.
    – Goodbye Stack Exchange
    Apr 4, 2019 at 13:11

4 Answers 4

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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...

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  • 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?
    – Goodbye Stack Exchange
    Oct 10, 2011 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, 2011 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!
    – Goodbye Stack Exchange
    Oct 11, 2011 at 17:25
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    It's also worth noting that, after some years passed, my shop was able to find a newer brake that solved the problem. Clearance is still tight but I can now run Schwalbe marathon racers.
    – Goodbye Stack Exchange
    Sep 5, 2019 at 3:38
2

Very late post here, but I had a similar issue on my Specialized Roubaix with Campy Dual Pivot Chorus Skeleton brakes. Simply go to a Shimano 6800 Ultegra or 9000 Dura Ace - or even 7800 Dura Ace, tons of clearance. I have a 700x28 on bike now, as much clearance as 700x25 with Campy brakes. IMO, as much as I love Campy, their brakes aren't the best, either in modulation or fit (as this thread indicates)!

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  • Dura Ace 7800 brakes are really tight for 28s - depending on the actual size of the tire, width of the rim, the exact location of the mounting boss on the frame, and even inflation pressure, 28s may or may not fit.
    – Andrew Henle
    Apr 3, 2019 at 12:26
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I've had a similar issue with 28mm tyres on an early 90s road bike. The frame was designed for 23mm, and 25mm fitted well-enough.

However I owned brand new 28mm tyres and wanted to fit them. After careful measuring, I used a woodworking file to take the mould line and sprues off the center of the tyre's tread.

That got it rolling, but there was still rub. I carefully filed the underside of the brake caliper to remove the paint and about half a millimetre of metal.

Then I used some red marker pen, fitted it all, and went for a short test ride. The points that were worn through the marker pen were high spots that rubbed on wheel/frame flex and I filed them a bit too.

Why did I buy too-big a tyre? Because I had 28mm on there already but they were 99% worn with a large flat spot in the middle which cleared the brake caliper.

One of the upshots is that I cannot mount the rear wheel if the tube is inflated because it won't fit through the brake blocks even with the tension released. And I cannot mount the rear wheel if the rear brake cable is released, because the rear caliper droops too much and interferes with the top of the tyre.

UPSHOT - check visually and see how close you are to fitting. Make a judgement call about whether removing the obstruction is safe or not. In my case, its the rear brake and it was quite beefy already.

I did not make any changes to the front brake and simply put up with a 25mm tyre there.

Separately - you may be able to get a small amount of extra room in the "shoulder" area by packing out the brake pads from the brake arms with a washer, and adjust the cable tension/position. Downside of this is the brake pads will be further out and may have more flex meaning worse braking.

Final option - does the frame support a disk brake caliper? Removing the rim brake altogether avoids the problem.

If you're feeling flush you could look for a coaster brake, but that loses the ability to have derailleur gears. A wheel with a Band brake or Drum brake might be a solution too, or an Internally Geared Hub with an integrated brake could do the job as well.

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    The problem is now a little different - the tires I want to fit are narrow enough but are rubbing against the caliper arms. My shop is looking into caliper brakes with more clearance, but if they can't find any I'll suggest a disk brake in the rear. I don't know if this would interfere with the fold (the bike has 16" wheels) but it's definitely a good idea!
    – Goodbye Stack Exchange
    Apr 4, 2019 at 13:24
  • A coaster brake hub could solve a lot of problems for you, or an IGH with a roller hub/band brake hub. Downside, cost and rebuilding wheel onto hub, and no front derailleur. Upside, cleaner, and brakes and better tyre choices.
    – Criggie ♦
    Apr 4, 2019 at 18:35
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    I can think of downsides to both disk brakes and coaster brakes, but it's good to have options. This all reminds me - I had a cruiser some years ago that had a rim brake on the front and a coaster on the back - it was strange at first but I got used to it pretty quickly.
    – Goodbye Stack Exchange
    Apr 5, 2019 at 1:49
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The universal solution to this problem is to add an additional quick-release (QR) somewhere in the brake cable route. The idea is to multiply QRs to release enough cable to the point where there is no cable tension at all. Once this is achieved a larger tire will fit. After the wheel is installed as you normally would, engage the two or three QRs to bring the pads back close to the rims for proper operation. I have completed this operation myself for brazed-on center pull Dia-Comp 610g calipers on my 1976 Centurion Pro-Tour. Also, I've used this method on my 2017 Trek Domane' SLR with Bontrager Speed Stop direct mount brakes using Shimano SM-CB90 in-line brake cable quick release.

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  • 1
    Thank you for contributing, but this addresses a similar-but-different question from what was asked. OP is asking about tyre clearance between the brake's caliper arms when set up for use, not about when adding/removing the wheel. Tyre/caliper rub while riding is the problem. Are you please able to review your answer? You obviously have relevant experience. Do take a moment to read the tour and learn how SE is a little different in its Q&A format.
    – Criggie ♦
    May 10, 2020 at 20:21

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