Caliper brakes that can accommodate a 28c tyre

[destry]

I want to run 28c tyres on my Roberts frame. There is plenty of room between the stays, but the brake bridge is low and the 105 calipers I have are within a whisker of fouling the tyre at about 10 and 2 0'clock. Does anyone know if there is a caliper that mounts higher on the bridge, or has a slimmer profile, than the 105? The bridge itself has a good 7 or 8mm of clearance.

Thanks!

[reohn2]

You need 57mm drop calipers,the 105's are most likely 49mm.
I run two bikes with 28c tyres one (Thorn Audax Mk3) has generous clearances and will possibly take 32mm tyres, both bikes have RX100 57mm drop DP calipers.
Shimano don't do RX100's these days but they do an alternative R650's,also Avid and other less well known manufacturers do them too.

[pedalsheep]

My Roberts has Shimano R600 calipers that fit comfortably round 28mm tyres.

[cadseen]

Bit confused here, the drop of the calipers has nothing to do with clearing the 28c tyres when fitting the wheel.
Sounds a bit simple but do your brakes have the cam thingy to open the brakes out temporarily ?

[reohn2]

Bit confused here, the drop of the calipers has nothing to do with clearing the 28c tyres when fitting the wheel.
Sounds a bit simple but do your brakes have the cam thingy to open the brakes out temporarily ?

I think you'll find that depends on rim width not caliper width.If you have a narrow rim and a wide tyre with the cam in the open position it may not open quit wide enough to allow the tyre to pass between the brake pads,with a wider rim the "starting" point could be as much as 5mm wider for the pads than a narrow rim with the same tyre fitted(say the two extremes of the rim's tyre capacity).
With a wide rim the same tyre would pass between the brake pads with cam open easily.This has nothing to with if the brake caliper is 49 or 57mm drop and everything to do with rim width.
Another factor is how close you run with you're brake pads to rim personally I like between 2and3mm between braking surface so a wider starting point still.
If someone has Campag or Tektro dropbar levers they also have an extra brake release on the lever itself in the form of a button thats pushed to allow the lever to open the caliper wider still.

If mudguards are fitted 57mm drop brakes are better on the appropiate frame clearances,with some frames you may juuuusssst get away with 49mm drop brakes but clearances may be starting to get close.

[CREPELLO]

Am I right in thinking the point has been missed here? The OP says the calipers are close to fouling the 28mm tyre at 10 and 2 o'clock. I take it that that means looking at the callipers in line with the tyre. So a longer reach caliper isn't going to help matters.

The original Shimano dual pivot might fit better - but what year or model number are these brakes? They seem to have recast the caliper profile for the newer DP's (changed around 2005?). My old RX100's look like they'd have more space around the tyre than the R650's. So the same may apply between old and newer short drop series brakes as well.

[CREPELLO]

The other thing is perhaps to change the model of trye.

[reohn2]

Am I right in thinking the point has been missed here? The OP says the calipers are close to fouling the 28mm tyre at 10 and 2 o'clock. I take it that that means looking at the callipers in line with the tyre. So a longer reach caliper isn't going to help matters.

The original Shimano dual pivot might fit better - but what year or model number are these brakes? They seem to have recast the caliper profile for the newer DP's (changed around 2005?). My old RX100's look like they'd have more space around the tyre than the R650's. So the same may apply between old and newer short drop series brakes as well.

After rereading the OP I think you're right Jerry

[PeterBL]

Sram Apex are standard reach brakes but should provide clearance for 28mm tyres, so maybe try those?

[Hypocacculus]

It's probably not terribly helpful but I've just had a look at my 105 DP short reach brakes which were new about a year ago. They don't protrude much below the bridge of my frame (a Mercian) - certainly not 7 to 8 mm. They are at their maximum extension (49mm) and are comfortably accommodating 25mm Schwalbe Marathons and mudguards. It looks like the first thing that would interfere with a wider tyre is the spring of the brake (although it has no problems with my mudguard), and my frame bridge which bulges a bit where the mudguard screws on, not the bridge of the brake. They look like they'd accommodate a 28 without mudguards (there is substantially more than 3mm clearance) if 28mm means 28mm but I doubt they would with mudguards in place. They definitely, definitely won't accomodate a 32.

[destry]

Many thanks for all your suggestions! As Jerry says, the problem is not with the brake drop, but with the low position of the brake bridge. It is the upper/horizontal part of the caliper arms that fouls the tyre -- especially on the r/h side when looking at it from the rear (as I have done for far too long over the last few days!). I know that these 105 brakes will easily accommodate a 28c tyre when fitted to a bridge that isn't so low. The bike is an Audax rather than a tourer and doesn't have mudguard clearance, but I must say I think it is a design weakness in a frame that is built for long distance riding and can clearly accommodate much bigger tyres between the stays. That said, it does make for powerful braking.

The problem is that I don't have a row of brake calipers sitting waiting to be experimented with... But maybe I should try and borrow an older Shimano dual pivot brake and try it out. As it happens, my son's Casati has a lovely Shimano 600 groupset, but he has seen what I'm up to and declared it out of bounds!

If anyone knows of any other DP brakes that are lean around the upper arms, let me know!

Thanks again.

[samsbike]

Sorry to dig this up but other using an older single pivot design is there a solution to this (other than narrower tires)?

[samsbike]

Sorry to dig this up but other using an older single pivot design is there a solution to this (other than narrower tires)?

[Brucey]

brake model? Brake drop? Photo?

cheers

[samsbike]

Actually reading the web I think the bridge issue is resolved by getting some older single pivot brakes. My problem is then finding brake pads that fit the older style single pivot brakes- I cant find anything reasonably priced.

Sam