Ultegra BR8070 caliper and Ultegra Ice Tech Rotors clipping/ rubbing

MikeeiJD7zA8

Morning all,

I have recently just replaced my front and rear rotors on my Road Bike.

I have a set of Mavic wheels and fitted the Ultegra Ice Tech Rotors (160mm) to them.

I have noticed that no matter how far inwards I push the caliper the inside (closest to the hub) is catching ever to slightly on the caliper. I know its the caliper and not the pads as it makes the ting or rubbing noise when they are out.

Now my question is. Can you get spacers to pad out the rotor (center lock) from the wheel hub. Or is there something else I should be doing?

Mike

katani

Are the mounting brackets attached to the caliper the correct way round? If you look on the side of the mounting bracket it should have an arrow marker on it to indicate which way up the bracket should be for either a 140mm or a 160mm rotor. Page 104 in the attached manual. Or are the brackets already in the setting for a 160mm rotor?

First.Aspect

Welcome to the world of disc brakes. Almost no clearance, so they rub. All the time, pretty much.

For this issue, retract the pistons, loosen the bolts holding caliper to frame, apply the brake (to centre the caliper) and tighten the bolts with the brakes applied.

MikeeiJD7zA8

First.Aspect said:

Welcome to the world of disc brakes. Almost no clearance, so they rub. All the time, pretty much.

For this issue, retract the pistons, loosen the bolts holding caliper to frame, apply the brake (to centre the caliper) and tighten the bolts with the brakes applied.

Pretty much what I done.....

But it still rubs like crazy. Hence the reason I was wondering if packing it out would fix it.

Guess I will just need to live with it until it wears down

i.bhamra

Is the noise continuous or at certain points of the disc rotation? Rotor may need truing? Mounting brackets the right way round and seated correctly as mentioned above is the first thing that comes to mind though.

MikeeiJD7zA8

i.bhamra said:

Is the noise continuous or at certain points of the disc rotation? Rotor may need truing? Mounting brackets the right way round and seated correctly as mentioned above is the first thing that comes to mind though.

Constant (i think). And the mount bracket only goes on one way for the 160mm caliper (not like the front one 140 vs 160)

I can move the caliper inwards slightly, but when tightening the bolts to 6nm

I will maybe see if gently bending the rotor slightly will fix it.

Mike

akh

I assume these are the same wheels and there was no rubbing before?

The rotor could be bent, or something could not be sitting square. Check over everything again.

I've heard of new rotors being very slightly bent. You won't see it with the naked eye off the bike. Get a bright light and watch the rotor between the pads as you rotate the wheel.

Push the pistons in with an appropriate tool before you try re-centring the calliper.

Try and ensure you torque the calliper, rotor lockring, and bike thru axle correctly and as consistently as possible. It won't make a huge difference, but tolerance can stack and the difference between rubbing and not can be <1mm.

First.Aspect

Try just turning the barrel adjuster a half turn to widen the blocks.

Oh, wait....

First.Aspect

akh said:

I assume these are the same wheels and there was no rubbing before?

The rotor could be bent, or something could not be sitting square. Check over everything again.

I've heard of new rotors being very slightly bent. You won't see it with the naked eye off the bike. Get a bright light and watch the rotor between the pads as you rotate the wheel.

Push the pistons in with an appropriate tool before you try re-centring the calliper.

Try and ensure you torque the calliper, rotor lockring, and bike thru axle correctly and as consistently as possible. It won't make a huge difference, but tolerance can stack and the difference between rubbing and not can be <1mm.</p>

Could try swapping the rotors front to back. That would tell you of it's the rotor itself or just a totally unnecessary technical development that's been rammed down our throats by the manufacturers.

MikeeiJD7zA8

Thanks, I will give this a bash tomorrow night after the kids go down

wongataa

You can get shims for the brake discs.

ed1973

I know this might sound daft but I had the same issue on Mtb bike. Turned out there was too much oil in the system meaning the piston couldn’t retract fully so was constantly rubbing. Solution, remove the pads, open bleed valve on lever, push piston back, clear up the mess of the small amount of oil from lever, close valve, replace pads, ride bike.
Hope it helps

pilot_pete

Remove the bleed screw in the shifter. Push the pads apart with the appropriate tool (so as not to damage them). If any fluid has welled out of the shifter bleed port there was too much fluid in the system preventing the pads from retracting fully. Wil up any excess and refit the bleed screw.

Ensure the rotor is not bent - use either the pads or something to act as a dial gauge if you don’t own one, to check for trueness. Gently bend the rotor as required in either direction to true it.

Now centre the calliper. Place a white sheet of paper or something similar below the bike in your eye line whilst viewing the pads/ rotor as you spin the wheel. If the gal isn’t even both sides, undo the calliper bolts just enough to be able to move the calliper. Nip one up - I usually to the lower one first, then the other. As you tighten them make sure the calliper doesn’t move with the tightening motion. Check again for equal gaps either side of the pads.

And that’s it. If this doesn’t solve your issue it may be that the calliper mounts need refacing to ensure they are true and square - you can get the appropriate tool, but they are quite expensive so probably best to get a cycle shop to do that for you.

I’m sure First.Aspect has his reasons, but I’ve never had problems with disc brakes that I couldn’t solve and the reliability and performance has been second to none. Plus I love the fact that they don’t chew my carbon rims up nor overheat them, and their performance is entirely predictable both in the dry and the wet.

First.Aspect

I was an early adopter, actually. I had a disc cross bike with road tyres on it as early as 2007, so avoid chewing through wheel rims over a longish winter commute. Great for that application.

But the engineering compromises to achieve better braking on a vehicle where the brakes aren't the limiting factor are hugely understated.

The braking load path now goes down the fork and via the spokes. In early days, there used to be a problem with brake chatter - a resonance in the front forks.

So now the forks are much stiffer and the wheels are also higher tensioned. The angle of the spokes from the hub to the rim is smaller, requiring still higher spoke tensions to compensate.

The end result is that the front end of every disc bike I've ridden is harsh and wooden. To compensate we are told to use ever wider (and heavier) tyres and lower pressures. But past a point, you lose information on the road surface. Also, the bikes feel skittish, a bit like a car with a too short wheelbase. Compliance with softer tyres isn't the same as the lost springiness through the rest of the bike.

Disc setups are more expensive as well, so have pushed prices up massively.

I do like the simplicity of mechanical cables - although I run Di2 - but I agree PP that disc brakes rarely go wrong and provide better braking. My main gripe is they are unnecessary in the first place and ruin most of the rest of the bike.