Rim brakes with biggest tyre clearance?

PMark

I am looking to get enough clearance around the brakes to fit 32mm GP5000s front and back. At the moment, 30mm tyres is probably the max I can use. So far I have tried AXIS 1.0, which are wide enough, but don't have a lot of clearance at the top (on the front brakes), so I got rub with just a 28mm GP4000 (which is closer to 31mm). The rears are OK (I could have probably got a 34mm in there), but the stopping power is noticeably worse than Shimano, so don't use anymore (probably because the dual pivot mechanism is at the top).

Then you have the Shimano 105 (have 5800 front and 7000 rear), which have more space at the top, but because of where the silver pivots are, a 32mm tyre would be a bit tight on the sides.


So I was wondering if anyone knows of any of dual pivot brakes that give similar stopping power to Shimano, but are a bit wider? I have tried searching around for precise dimensions of SRAM and campy brakes, but haven't had much luck (are they even comparable to Shimano as seem to be similar design to the AXIS brakes?). When I measured the front 105 5800 brakes, I get 34mm inside the brakes, between both pivot bolts.

trevor.hall12

You can get upto 32mm with Shimano R451s ,they do have a longer drop though

DeVlaeminck

Velo Orange Grand Cru - not cheap though (I've never used them just read reviews)

akh

trevor.hall12 said:

You can get upto 32mm with Shimano R451s ,they do have a longer drop though

The same with Shimano BR650s. I have those on one bike and they're easily wide enough to accommodate a 28mm GP4000s II with bags of room to spare.

Braking performance isn't nearly as good as 5800 brakes when paired with an 11 speed lever though. Some of this might be down to the longer arms, but Shimano's own website points out that all their long drop brakes perform less well with current levers. I heard this is due to the long drop brakes being from the 10 speed era (or earlier) and having a different pull ratio, but unsure.

https://productinfo.shimano.com/#/com?cid=C-737&acid=C-456

davebradswmb

The greater the distance of the pads from the pivot point the less pressure you will be able to exert on the pads = less friction = lower braking performance. It is this reason why alternative types of brakes were developed for mountain bikes before the advent of disc brakes.

I have the same issue with the Tektro brakes on my winter/commuter bike, same pads as on my best bike but much less braking power. I've seen a lot of negative comments about the Tektro brakes but from my observations they are just as well made as the cheaper Shimano brakes and the lower performance is only due to the fact that they are often used when the standard Shimano brakes are too short.

simon_e

akh said:

The same with Shimano BR650s. I have those on one bike and they're easily wide enough to accommodate a 28mm GP4000s II with bags of room to spare.

Braking performance isn't nearly as good as 5800 brakes when paired with an 11 speed lever though. Some of this might be down to the longer arms, but Shimano's own website points out that all their long drop brakes perform less well with current levers. I heard this is due to the long drop brakes being from the 10 speed era (or earlier) and having a different pull ratio, but unsure.

The R451 are longer drop than 105, Tiagra etc but have a different pull ratio to the older R450 and R650 long-drop caliper models. From SJS Cycles' product page:

Must be used in conjunction with ST-4600, ST-4603, ST-5700, ST-5703, ST-6700 or ST-7900 STIs for correct leverage ratio

PMark

Thanks, will keep an eye on eBay for a deal on those Velo brakes, as the reviews seem to rate them over the Shimano ones.

rwoofer

TRP 957s are the best long drop brakes I've found. Substantially better than R451s, but not as good as Ultegra/Dura Ace.