New Carrera Fury brake problem?

z1ppyuk

Hi all

Let me start by saying I'm a total newbie and so know next to nothing about bikes. Today I have just picked up a new Carrera fury from Halfords as I want to get into cycling and attempting off road a bit later.

The problem I have is that upon getting the bike home I have noticed a scraping/rubbing sound coming from the rear brake system when the rear wheel spins. What concerns me is that the sound only happens for part of the rotation, possibly suggesting the disc is slightly warped?! I certainly hope not, but not knowing enough about the bike I thought it would be wise to get the opinions of those more knowledgeable! I will be going back tomorrow (Friday) but don't want to be fobbed off with a botch fix or anything.

Anyway, I'd be really grateful if anyone could shed some light on what may be wrong and what may need attention/fixing.

Andy

nicklouse

let the brakes bed in.

Ie go use but dont get them too hot for the first bit.

delta5

Its common for rotors to get a bit warped - the gap to the pads is very small so even a slight bash can set them rubbing. Usually nothing to worry about, just fix it.

To solve it, find out where on the rotor it's scraping:

take an imaginary index line from the axle through the disk pads to the rim spin the wheel, but not too fast, and listen for when the disk scrapes at this point in the rotation, mark the position on the tyre where the index line crosses now do the same while looking carefully through the gap between the pads and rotor - you will see the rotor touch the pads as the position marked on the wheel crosses the index line. Check whether its the inner or outer pad that's catching. If it's badly warped it might alternate rubbing on both sides!

Now you know where its scraping, you can fix it by either

gently bending the rotor to correct the warp. No need to remove the wheel or rotor - just grip it with a clean dry cloth or clean gloves to avoid getting any grease on it, and flex it with your thumbs, or adjusting the position of the caliper relative to the rotor (Note: this will only work if the warp is very slight). Slightly loosen the hex bolts holding the

caliper to the adaptor (not the adaptor to the frame) then gently tap the caliper in the required direction, spinning the wheel to check when the scraping stops, then tighten the hex bolts. Don't overtighten them!

You'll probably be doing this every so often - although it might seem tricky a first it becomes much easier with practice.

Then one day your front rotor will start randomly making a high ssssring! noise. Now solving that is another story . . (and one which I'm still working on )

kaytronika

Delta5 wrote:

Then one day your front rotor will start randomly making a high ssssring! noise. Now solving that is another story . . (and one which I'm still working on )

I see that happening quite a lot on the trails... i thought cantilever squeal was annoying!

chedabob

kaytronika wrote:

Delta5 wrote:

Then one day your front rotor will start randomly making a high ssssring! noise. Now solving that is another story . . (and one which I'm still working on )

I see that happening quite a lot on the trails... i thought cantilever squeal was annoying!

Apparently it's the retaining spring on the Juicy 3s. It could also just be dirt in the caliper. Mine make so much noise when they get the slightest bit of mud in them, and they make a deafening sound if they get wet.

kaytronika

chedabob wrote:

Apparently it's the retaining spring on the Juicy 3s. It could also just be dirt in the caliper. Mine make so much noise when they get the slightest bit of mud in them, and they make a deafening sound if they get wet.

Here's me thinking replacing my V-Brakes with discs would solve all my braking problems.

XCITEYORKSHIRE

My advice would be to just take it back and see what Halfords says at first...

Have you actually knocked it though? If so, and they won't replace the rotor for you then DO NOT try to repair it by bending it here and beinding there, marking up your tyres, etc...

It's just a waste of time and a cause of unecessary frustration...

Instead -

...and for how much they cost just buy a new one from Superstar - http://superstar.tibolts.co.uk/product_ ... cts_id=197

or for a posh one

http://superstar.tibolts.co.uk/product_ ... cts_id=202

chedabob

XCITEYORKSHIRE wrote:

My advice would be to just take it back and see what Halfords says at first...

Have you actually knocked it though? If so, and they won't replace the rotor for you then DO NOT try to repair it by bending it here and beinding there, marking up your tyres, etc...

It's just a waste of time and a cause of unecessary frustration...

Instead -

...and for how much they cost just buy a new one from Superstar - http://superstar.tibolts.co.uk/product_ ... cts_id=197

or for a posh one

http://superstar.tibolts.co.uk/product_ ... cts_id=202

It's not a defect. As Nicklouse said, bed them in first. Disc rotors are stamped, so they don't always come out perfectly flat. If you go to Halfords, they'll tell you to bed them in, and then straighten them out by hand. If they were properly warped, the wheel wouldn't move at all.

z1ppyuk

Thanks guys that's some really useful advice, and of course I'm relieved as I can now relax and start enjoying the bike!

You're right chedabob and nicklouse - I called Halfords this morning and that's exactly what the guy told me to do!

Nice to know it's not an expensive part anyway if it ever does get warped. I'm so new to this bike malarkey that I was a bit disappointed it wasn't 'perfect' when I picked it up!

Thanks again, really appreciate the help.

delta5

just take it back and see what Halfords says

. . if you are looking for a waste of time and a cause of unnecessary frustration.

DO NOT try to repair it by bending it here and beinding there, marking up your tyres, etc...
It's just a waste of time and a cause of unecessary frustration..

It takes less than 10 minutes. And defeating an annoyance is very satisfying. I've done it five or six times on my Fury in the last few years. I'm still using my original rotors.

just buy a new one

Follow that bs and you'll be buying a lot of new rotors.
Its doesn't take a hard knock to upset them - even just taking the wheel off to change a tyre, or letting them get very hot, can get them scraping a little. Although the discs are very hard and the braking area does not bend easily, the rotor spokes have some flex in them which you can exploit by pushing on the rim of the disc to get it running true again. The warp, and thus the remedial flexing required, is usually very small - in the range of about 0.1 - 0.3 mm. Just don't use too much force - be patient, applying lots of little pushes rather than a few a big ones, and checking the clearance after each attempt.