do GP4000IIs 28's fit under normal brakes?

[bicycletricycle]

Continental GP4000IIs in 700x28 are my preferred go fast tire these days. Most of the time they end up measuring something like 30 millimeters wide depending on the rim width. I think this is a bit of a stretch for normal short reach (49 millimeter) brakes but I am not sure. I don't have a bike that has short reach brakes on it anymore. I am trying to decide what brakes to spec on my new Zanc Max. I have been going back and forth which is probably really annoying for Mr. Zanconato. On the one hand a short reach set up will allow me to run super cool lightweight wiz bang brakes and also make this bike stand out more from my others, on the other hand medium reach brakes will allow me to run a few other nice tires (700x30 cypress, jack browns, stampede pass, etc) and those Velo Orange medium reach brakes are great.

So, do 30 millimeter wide GP4000IIs fit under normal road brakes?


* for everyone saying it depends on the frame you are right, however, this is a custom frame and it can be built with the brakes at the bottom of the slots with plenty of room at the stays.

[weisan]

So, do 30 millimeter wide GP4000IIs fit under normal road brakes?

no

[Davist]

My buddy has zipp 303s and tried to use GP4k 28s. The brakes are ultegra 6800, the tire rubbed the chainstay of his cannondale supersix evo (which is "supposed" to clear 28s) but not the "knuckles" of the brake pivots.

[Mark McM]

That depends largely on the frame & fork (and the position of the the brake mounting holes).

I haven't tried the 700x28c GP4000IIs, but 700x28c Grand Prix 4-Seasons fit fine on my steel Nobillette with Campagnolo Centaur dual pivot brakes.

[Ed-B]

I'm running the GP 4000IIs tires in the 28mm width on a few bikes with short reach brakes. These tires measure about 29mm-30mm on my rims.

The key factor is the depth of the pads in the caliper arms. If this adjustment has the brake pads near the bottom of the slot then it will likely work. You may need to use the brake's barrel adjuster in addition to the quick release to get the caliper open enough to clear an inflated tire. But, yes, bikes with short reach brakes can accept these larger tires if the frame is built with the brake reach at or about the max reach of the caliper, 49mm. A custom builder can do this.

Personally, I'd play it safe and go with a 57mm reach brake. I'd have the frame built with the reach set to about 55mm to give more clearance in the caliper and in the frame. You won't have to worry about picking up a stick, or sharp bit of gravel, and having it grind through the minimal clearance you'd have with the short reach brakes. And you can get a caliper with a wide tire quick release for simple wheel swaps.

[yinzerniner]

Originally Posted by Davist

My buddy has zipp 303s and tried to use GP4k 28s. The brakes are ultegra 6800, the tire rubbed the chainstay of his cannondale supersix evo (which is "supposed" to clear 28s) but not the "knuckles" of the brake pivots.

Does your buddy have the 2017 or later evo, or the 2016 or later hi-mod? The previous gens of both could barely fit a real 28mm width tire on the rear with roughly 1mm clearance on each side. Know this from real-world experience.

As to the OP, it's really dependent on the frame, fork, brake and what he means by "clear." Some frames mount the brakes higher than others, while some brakes have larger openings when in the closed/open position, and does the OP mean "clear" when installing and removing the wheel while inflated, or is deflated OK?

Here's a couple points as to how theoretically similar bikes are very different when it comes to brake/tire/wheel clearance.

2012 CAAD10 54cm
25mm GP4Ks
Easton R90SL Rims (19.5mm ID)
Force brakes / 6800 brakes

Everything fits pretty well with 2mm clearance at chainstays and 3-4mm to brake, tire has to be deflated for installation with the Force brakes. Same with the Ultegras.

2013 Supersix Hi Mod 54cm
Same tires, wheels and brakes as above wheels install with deflated tires, but wheel doesn't even turn when tire inflated. Stuck at chainstays and there's roughly 1mm of clearance to brake on the Force with about 2mm with the Ultegras.

So to the OP, with any modern-width rims (more than 17mm ID) the larger GP4ks most likely won't work very well if at all with short-reach brakes.

[prototoast]

If this is a custom bike, he should be able to build it with the brake bridge at the maximum height for "normal" reach brakes, and they will be fine.

[biker72]

The GP 4000II's 700X28's measure 29.5mm on my Ultegra wheelset. Standard Ultegra brakeset has ample reach. Looks like about 2+mm clearance best I can measure.

[bicycletricycle]

Obviously it depends on a lot of things, I am wondering if people have had it work on their actual bicycles. 4 seasons are really narrow

Originally Posted by Mark McM

That depends largely on the frame & fork (and the position of the the brake mounting holes).

I haven't tried the 700x28c GP4000IIs, but 700x28c Grand Prix 4-Seasons fit fine on my steel Nobillette with Campagnolo Centaur dual pivot brakes.

[donevwil]

I tried GP4000IIs 28s mounted to Hed (not +) wheels on my wife's Hampsten GPTi with Record skeletons DPs, cleared the rear fine but not the Enve fork crown. Have not tried them on her Kirk with steel fork, but can if it matters.

[dddd]

The model year of the caliper (7800 vs. 8000, 9000 vs. 9100) can make a difference.
I'm less familiar with Campy's or SRAM's calipers, but suspect their newest ones might also be more versatile.

It will be best to use such high-quality calipers such as these or other higher-end offerings, because their modulation performance is better for various technical reasons, not to mention their lighter weight.

I agree with the others that rim width and especially the height of the frame/fork's mounting holes can make a critical difference when wanting to use tires up near 30mm in actual width.

[jemdet]

No problems using them with 7403 and 7700 brakes.

That was with 4000s in 28 mounted on an MA40 front and TB14 rear. The sizes were in line with what others have posted. A little wider on the TB14.

This was on a frame that I built myself; I maximized the brake bridge height and ATC (well, axle-to-brake-hole).

[Davist]

Originally Posted by yinzerniner

Does your buddy have the 2017 or later evo, or the 2016 or later hi-mod? The previous gens of both could barely fit a real 28mm width tire on the rear with roughly 1mm clearance on each side. Know this from real-world experience.Here's a couple points as to how theoretically similar bikes are very different when it comes to brake/tire/wheel clearance.

2012 CAAD10 54cm
25mm GP4Ks
Easton R90SL Rims (19.5mm ID)
Force brakes / 6800 brakes

Everything fits pretty well with 2mm clearance at chainstays and 3-4mm to brake, tire has to be deflated for installation with the Force brakes. Same with the Ultegras.

2013 Supersix Hi Mod 54cm
Same tires, wheels and brakes as above wheels install with deflated tires, but wheel doesn't even turn when tire inflated. Stuck at chainstays and there's roughly 1mm of clearance to brake on the Force with about 2mm with the Ultegras.

So to the OP, with any modern-width rims (more than 17mm ID) the larger GP4ks most likely won't work very well if at all with short-reach brakes.

He has the '17 supersix evo standard which was "supposed" to fit, probably would have on a narrow rim, but not a zipp..

I fit 32s on my CAAD 10 with archetypes, had a '16 supersix evo, couldn't fit some 25s (Michelins) with archetypes, 25s fit on narrow (DA C24) rim though.

My GP4kS2 28s puff out to around 33 on a 25mm wide OD rim. The GP4 season 32s measure the same on a 23mm rim (somewhat OT as I use disc brakes now, but some data points)

[merckx]

Mike built a frame that was designed for 49mm calipers with the pads resting in the bottom of the slots. I was able to shoehorn 32mm tires on that frame. However, I prefer mid-reach brakes (57s), and the breathing room that they offer. My current Zank is mid-reach with the pads very close to the bottom of the slots. I can shoehorn 40mm Clement MSOs on this frame.

[Mike Bryant]

I run GP4KS2s on Zipp 202s under Shimano Ultegra BR-6800 without problems. Bottom of slot on rear. Didn’t work with an Edge (Enve) fork up front, too tall. Though fine with an Ouzo Pro.


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