Has anyone gone from 6800 brakes to R8000?
I've installed 28mm GP4000s tyres on my bike and I'm getting a squeak from the tyre rubbing on the caliper every now and then.
There's plenty of frame clearance, but the caliper is very close.
I was going to purchase the R8000 brakeset hoping that would remedy the problem.
6800 to R8000 brakes
Moderator: robbosmans
You can put a thicker (or multiple) washer(s) on the caliper bolt to get the caliper a tiny bit further away from the wheel. See if that fixes it.
Just make sure you got enough turns on the caliper nut before it tightens. You don't wanna be holding it by just 1-2 turns. You need a longer recessed nut in that case.
Also when you tighten the nut to the calipers you can try and use whatever space there is in the mounting hole to your advantage by just putting some pressure away from the wheel when tightening.
/a
Just make sure you got enough turns on the caliper nut before it tightens. You don't wanna be holding it by just 1-2 turns. You need a longer recessed nut in that case.
Also when you tighten the nut to the calipers you can try and use whatever space there is in the mounting hole to your advantage by just putting some pressure away from the wheel when tightening.
/a
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Do try to keep the 6800 brake washer on the carbon side. It is friendlier to carbon and won't chew it up like the toothed washers supplied on older brakes.
[14lb(6.35kg) of no carbon fiber]
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Those are some great tips for squeezing out a little more clearance on a standard sidepull frame.alcatraz wrote: ↑Sat Apr 28, 2018 1:25 pmYou can put a thicker (or multiple) washer(s) on the caliper bolt to get the caliper a tiny bit further away from the wheel. See if that fixes it.
Just make sure you got enough turns on the caliper nut before it tightens. You don't wanna be holding it by just 1-2 turns. You need a longer recessed nut in that case.
Also when you tighten the nut to the calipers you can try and use whatever space there is in the mounting hole to your advantage by just putting some pressure away from the wheel when tightening.
/a
With the increasing popularity of wider tires in general and in particular for gravel riding, there are a lot of people who are playing a game of millimeters trying to get a little more cushion to fit on their existing bike, which was likely designed around 23-25mm originally. I'd found it surprising that noone offers a kind of offset caliper where the brake caliper is offset upwards vs. the mounting bolt, so that the frame/fork clearance then becomes the only limiting factor, rather than the caliper itself. To the OP, on the Shimano topic, if you get the opportunity, you may also want to check out the new 105 calipers. I had heard that they were designed to allow more clearance, however it is unclear to me if that simply means that it is a trickle down of the 8000 design or if the 105 calipers actually have more clearance than 8000, due to the design being a year newer and therefore giving the Shimano engineers more time to take into account current trends. If anyone has the opportunity to check them out side by side, please report back, as I'd like more room for 28mm or even 30mm tires on my current ride.
There are also some smaller manufacturer calipers, like certain TRP models, that offer more tire space, but I don't have any specific suggestions other than if you have a friend or friendly shop that has some laying around, then give them a try. Depending on the design of brake, on some calipers the clearance increases at the top of the tire as the brake is squeezed. If you run a thinner pad, you can then tighten the cable, such that the default position offers more clearance but with the same amount of lever throw required to activate the brake. The same goes for narrower rims, however that kind of goes contrary to the current wider tire trend.
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Bigger Gear
- Posts: 560
- Joined: Fri Mar 27, 2009 6:58 pm
- Location: Wet coast, Canada
I know in the case of friend of mine running a DA9000 group on a Cannondale SuperSix EVO, with Conti GP4000 28s, he had some problems with small debris getting caught in the brake. The clearance was super tight. He swapped to the 9100 calipers and got just a bit more clearance and seems to have much less problems. The 9000 calipers have a bit of a knuckle on the left pivot that is a little less pronounced on the 9100. The 6800 to 8000 might also be the same, but I can't say for certain.
I have this when riding over newly laid chip-seal. Stones stick to the tyre and then jam the rear tyre against the calliper. There is plenty of clearance normally. Bloody annoying it is too. Not sure that it's worth getting 9100 callipers tho as the marginal improvement won't stop many larger stones from continuing to get stuck.Bigger Gear wrote: ↑Tue May 01, 2018 7:02 amI know in the case of friend of mine running a DA9000 group on a Cannondale SuperSix EVO, with Conti GP4000 28s, he had some problems with small debris getting caught in the brake. The clearance was super tight. He swapped to the 9100 calipers and got just a bit more clearance and seems to have much less problems. The 9000 calipers have a bit of a knuckle on the left pivot that is a little less pronounced on the 9100. The 6800 to 8000 might also be the same, but I can't say for certain.
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pinkertonpunk
- Posts: 10
- Joined: Tue Jun 05, 2018 7:34 pm
Anyone ever actually try this out? My wife and I are running GP4000SIIs in 28c on our Emondas (SL 6 and ALR 6) with Ultegra R6800 and in the dry there is no rubbing. As soon as it gets wet you get small debris that starts rubbing on the tire that is stuck in the caliper. There is so little clearance so I was hoping to get R8000 calipers and call it a day.
Hi, I purchased the R8000 brakes and fitted them on my ALR.pinkertonpunk wrote: ↑Sat Nov 24, 2018 5:52 amAnyone ever actually try this out? My wife and I are running GP4000SIIs in 28c on our Emondas (SL 6 and ALR 6) with Ultegra R6800 and in the dry there is no rubbing. As soon as it gets wet you get small debris that starts rubbing on the tire that is stuck in the caliper. There is so little clearance so I was hoping to get R8000 calipers and call it a day.
There's more clearance but not as much as I was hoping.
The GP4ks in 28mm measure 31mm when inflated so I've gone back to 25mm which are also oversized.
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Hi! I'm in a similar pickle right now.hlvd wrote: ↑Sat Nov 24, 2018 8:05 amHi, I purchased the R8000 brakes and fitted them on my ALR.pinkertonpunk wrote: ↑Sat Nov 24, 2018 5:52 amAnyone ever actually try this out? My wife and I are running GP4000SIIs in 28c on our Emondas (SL 6 and ALR 6) with Ultegra R6800 and in the dry there is no rubbing. As soon as it gets wet you get small debris that starts rubbing on the tire that is stuck in the caliper. There is so little clearance so I was hoping to get R8000 calipers and call it a day.
There's more clearance but not as much as I was hoping.
The GP4ks in 28mm measure 31mm when inflated so I've gone back to 25mm which are also oversized.
How much more clearance would you say you gained going from 6800 to r8000 (in the rear)? 1mm? Upwards aswell as sideways equally?
