Front disc break rubs when steering left or right?

[WhiteEagle197]

See if it settles down, how is it under hard cornering ?

Once it's beyond 5° or so, it doesn't matter, it does the rubbing sound. Turning 10° or 15° or even more doesn't make a difference, i.e. the rubbing doesn't get worse that at 5°.

 

[WhiteEagle197]

Also, is the disc securely/properly fitted to the wheel hub? I'd imagine the fitting is the 6-bolt type where there are 6 hex bolts attaching the disc to the hub... check all are (approx) equally firm. If the disc isn't sitting properly it might be twisting and forcing air flow while cornering causing a hiss.
TBH it could be nothing to do with the wheel or disc. People have been known to discover that a creaking bottom bracket turned out to be their helmet strap when they turned their head a certain way!
bb

It's definitely the front brake. The screws seem okay. I will have the wheel hub checked. Maybe ask them to true the disc further or put up a new one. But it might be that the fork itself bends/flexes a bit - I guess nothing can be done with that? (Yeah, it was "only" a £500 bike, maybe I should have bought a £1500 one? I thought this one would be more than enough as I'm not a racer.)

 

[bonsaibilly]

£500 is more than enough to expect a bike to work properly

A simple brake adjustment is to loosen the two caliper bolts slightly (I'm surprised if you cannot get them at all loose - they must be resolveable) then depress the brake lever hard and keep it depressed, then re-tighten the caliper bolts. Release the lever... This should have the effect of centring the brake pads position around the disc.

 

[Levo-Lon]

It could very well be a little flex in the fork

my thoughts too...
sounds like thread lock on the caliper bolts is well set..
pop the bike to the shop to get the bolts checked ..if you cant move them as sheared or rounded out bolts are not funny.

 

[Yellow Saddle]

Don't worry. It is pretty common and all bikes do it albeit most without the noise. A bicycle is not infinitely rigid and when you turn or pedal hard, things flex. Going around corners cause a bit of flex too and if your brakes are very close to start off with, they will touch. The solution is to fiddle with the brakes until you get enough clearance to not cause the noise when cornering. The pads themselves will wear but that won't increase clearance since the pads automatically advance as they wear, keeping clearance constant. Pad roughness could be an issue and if you inspect them and they're not perfectly flat, a bit of sandpaper will help. A disc that's not perfectly true will also cause rub but then you would have reported a cyclical rub rather than what I perceive to be a constant one as you corner.
It happens on road bikes too, especially in the wet where grit in the water on the rim sidewall effectively reduces clearance and amplifies the noise from touching.
I've had similar issues on a bike with a high-end fork and wheels that I built myself. It isn't a component quality issue but just....life.

 

[WhiteEagle197]

Thank you all for all the answers. I'll take it back to the shop, and will see what happens.

 

[WhiteEagle197]

Solved. Took it back to the shop. They had to true the disc and adjust the callipers. No it works perfect, nor rubbing whatsoever. Thanks for all the help.

 

[bonsaibilly]

What, so they loosened the 6 bolt on the disc then centred it and retightened them; then loosened the two caliper bolts, squeezed the brake and then retightened the bolts; and used force of hand to reform any lateral distortion a fraction of a mm on the disc...

BB

 

[fossyant]

All just slightly out of alignment.

 

[WhiteEagle197]

What, so they loosened the 6 bolt on the disc then centred it and retightened them; then loosened the two caliper bolts, squeezed the brake and then retightened the bolts; and used force of hand to reform any lateral distortion a fraction of a mm on the disc...
BB

I didn't see the process, as no customers allowed in the workshop...

 

[bonsaibilly]

All just slightly out of alignment.

Domino effwct

 

[mickle]

Woah! Stop! Take it back to the shop. No not pass go. Do not attempt to fix it yourself. It's covered under warranty. You have consumer rights which disappear the instant you start to fark about with it. End of thread.

 

[Tim Hall]

Woah! Stop! Take it back to the shop. No not pass go. Do not attempt to fix it yourself. It's covered under warranty. You have consumer rights which disappear the instant you start to fark about with it. End of thread.

Keep up there mickle. He's done exactly that and they've fixed it.

 

[keithmac]

Sometimes taking the disk off and turning it on its mounting face to clean the mating surfaces is enough to true the disk.