rear discs working but wheel moves extra inch

chocolatetiger1

Hi im new here. Really grateful for any advice.
Just bought husband a diamondback apex. Nice 29er. I know v little about bikes but v good w cars/prac stuff. Rear hydraulic discs are stopping the wheel and the bike fine but then the wheel moves about another inch with the brakes on okwith a clunk cracking sound, padsok and not moving checked and tightened all mounts etc. Any ideas would b v v grateful. Husband moaning doing my head in.
Cheers ct

cooldad

Something is loose. Checked the rotor(s)?

The Rookie

Is it really an inch?
1/ Pad moving in calliper, 1" (genuine) at the tyre will be about 5mm at the pad
2/ Rotor bolts loose (that would give at most 1mm or about 5mm at the tyre)
3/ Axle moving in dropout, try tightening the QR

jimothy78

The Rookie wrote:

Is it really an inch?...

I agree with you that the real movement is probably less than it feels like.
However:

2/ Rotor bolts loose (that would give at most 1mm or about 5mm at the tyre)

not sure about this, if the rotor bolts are (I think) about 1" from the axle, then every 1mm of rotational movement there is going to be translated into 14.5mm of movement at the tyre/floor. (as the radius of the wheel is going to be (hopefully) 14.5" on a 29er)

chocolatetiger1

Thanks for the replies!

Oxoman - I've centralised the calipers already front and back and it solved the problem of the front one 'catching' but this is different on the rear. I think the QR is OK - will recheck it.

cooldad, rooky and jimothy - going to recheck QR and axel bolts

Other than just tightening it is there a specific check I should be doing on the QR to know I've got it right/tight enough - this was set up by the factory as rear wheel was in place when it arrived so ? if it's OK. I'm a bit unsure about the quality of the set up of this bike as they even managed to get the tread pattern on the rear tyre facing the wrong way - an easy mistake I suppose - but on a brand new bike of RRP 800 not good enough.

I am a novice (and a girl ) but really keen to learn but removing the rear wheel to sort out the tread pattern when the bike is brand new I can't be bothered.

I phoned Parker's of Bolton where I bought it from who were really off hand (they'd been really nice when I phoned before buying the bike) and said just take it to a LBS. Basically weren't interested and OH eventually got them to agree to collect and refund - but I don't want rid of the bike - that's the daft part - if this is a servicable problem it would be better fixed but no help from them so if I can't sort it in the next 24h back to the shop it goes.

Thanks for all your help - CT

cooldad

Read 'Read this first' below - useful stuff.
I think it has centrelock hubs so you'll need a cassette tools to check the rotors.

thelonegroover

Shimano centre lock disks may need tightning, in fact all the bikes I've had with these disks have had a bit of play after being ridden a couple of times. Any local bike shop should be able to do it free or for a very small charge.

chocolatetiger1

Chhers for helpful replies!

I've tightened the centre locking discs (Super helpful guys at Merlin bikes), checked the QR, tightened the axels, still massive play in both wheels and no joy at all.

Giving up now.

cobba

The brake pads will have a little bit of forwards/backwards play when they're in the brake caliper, they aren't an exact fit. Some brakes will have more movement then others.

If you engage the brake and try to rotate the wheel forwards and then try to rotate it backwards there will be some movement with the wheel, it's nothing to worry about.

A millimeter or two of play with the pads in the brake caliper will give a lot more movement at the outer edge of the tyre.

When you're riding the bike the wheel only rotates one way so you won't notice or get the forwards/backwards play with the pads.

I think that you might be worrying about a problem that isn't there.

thelonegroover

chocolatetiger1 wrote:

Chhers for helpful replies!

I've tightened the centre locking discs (Super helpful guys at Merlin bikes), checked the QR, tightened the axels, still massive play in both wheels and no joy at all.

Giving up now.

If theres so much play, surely you can tell where it's coming from.