Brake caliper out of position?

[Yellow Saddle]

Why not start off by finding out where the movement happens. Carefully mark the position of the mounting pillar against the frame once you have it all adjusted. Ride and then see if the two positions are still together or not. That will tells us a bunch of things to suggest.

Secondly, anyone that told you not to brake so hard is stupid.

 

[jonny jeez]

Is the wheel properly seated in the dropouts?

 

[boydj]

Where does the brake sit naturally when the nut is loose? This should let you see if the cable outer is the right length.

 

[RoubaixCube]

Heres a few pics if it helps

cable on triban for comparison:

I think ive left plenty of space. between the rims and the pads.

I do like having my brakes set up pretty close to the rims as it means i dont have to apply much pressure to the brakes to before i start slowing down - This wouldnt be a problem at all if the caliper wouldnt stop being pulled out of position.

Ive already reseated the wheel just to make sure that it wasnt the problem.

 

[raleighnut]

Heres a few pics if it helps

cable on triban for comparison:

I think ive left plenty of space. between the rims and the pads.

I do like having my brakes set up pretty close to the rims as it means i dont have to apply much pressure to the brakes to before i start slowing down - This wouldnt be a problem at all if the caliper wouldnt stop being pulled out of position.

Ive already reseated the wheel just to make sure that it wasnt the problem.

Outer is clearly too long (only by a few mm though)

 

[RoubaixCube]

Outer is clearly too long (only by a few mm though)

I thought so too. Im not working this friday so i guess i'll swing by my LBS and see if they could give it the snip (hurrhurr) rear derailleur needs a little indexing too and im not great at that yet so i'll hit two birds with one stone.

The first guy at CRC did say he would take about 5mm off the outer when i first took the bike in.

I wonder if anyone else can second raleighnut's opinion?

 

[Ajax Bay]

Seconded: it's too long - should not bend up and then down. See my previous post: "The cable outer ('black sleeve') should display a shallow arc to the locking nut on the brake without bending 'up' first." Note that Triban has to, to get the angle right, because the top tube /seat tube is comparitively lower.
But I do not think this will necessarily solve the problem, which I reckon is probably caused by the through bolt/nut not tight enough.
Edit: I'd also have the bottle screw ('Cable adjusting bolt unit') unscrewed half way, so you have adjustment both ways. At the moment it's right 'in'.

 

[sight-pin]

The cable is definitely not entering straight as raleighnut suggest, the Triban looks straight in comparison.

 

[Tojo]

I would say the same, the outer cable is too long between the top tube and the caliper, shorten it enough to let the outer rest against the extended part of the seat tube and give it a straighter run, basically give that section of outer the shortest run you can when you have re-centred your caliper.

 

[Broadside]

The OP States it is the right pad that makes contact not the left. While the outer cable may not be the perfect length with it being a touch long, this would have the effect of pushing on the caliper and forcing the left pad on to the rim, not the right.

If the cable was too short you might argue it could have the opposite effect and pull the caliper however the cable end has no purchase on the caliper because the cable just loosely sits in the caliper. I think the cable length is a red herring.

 

[RoubaixCube]

The OP States it is the right pad that makes contact not the left. While the outer cable may not be the perfect length with it being a touch long, this would have the effect of pushing on the caliper and forcing the left pad on to the rim, not the right.

If the cable was too short you might argue it could have the opposite effect and pull the caliper however the cable end has no purchase on the caliper because the cable just loosely sits in the caliper. I think the cable length is a red herring.

With that said, what do you think it could be thats causing the issue?

 

[Broadside]

See my earlier post. It is almost certainly the bolt that attaches it to the frame that needs to be tightened, but how much you want to tighten it yourself is another matter. I wasn't comfortable tightening so much on a carbon frame so let the shop do it.

My wife's bike had this problem from new. We tried trimming the sleeve which made no difference.

I posted the problem on here and was told to keep on tightening the 6mm hex socket on to the frame, but estimated it was already at about 10nm so didn't want to go further as its a carbon frame etc.

We kept taking it back to the shop where we bought it and they were puzzled by it but kept tightening it a little more and it seems to have stopped now. I'm guessing it must be torqued up to around 15nm, much tighter than I would have been happy doing myself on a carbon frame, but it seems fine now.

 

[Ajax Bay]

@RoubaixCube - when the right caliper starts fouling, after you've ridden for a bit (and used the brake several times), on examination, has the left caliper moved away from the rim. This is effectively the same suggestion as @Yellow Saddle made, but may be easier to do. If so this would confirm the calipers are rotating in the frame. I assume, on the road, you just twist the calipers back into a non-fouling position and carry on.
Would the insertion of a serrated washer between the brake calipers and the carbon frame and tightening to specification risk damaging the carbon? If this is the solution to your issue (and thanks to @Broadside for reiterating my early suggestion of just tightening it till it doesn't move), you have to increase the friction by either this or just tightening it till it doesn't move. At the same time, reduction in the outer's length may reduce the (small) force which may be rotating the calipers if, as @mjray has mooted, there's a bit of a sticky pivot in there too. Quick squirt of oil for all the pivots perhaps, anyway.