Rear wheel bearings?

[eldudino]

Hi All, first post for me!
I've got a Trek SU200 that I use for commuting and I recently replaced the brake pads. Whilst doing this I clamped up the rear wheel but as I put it back on and folded over the quick release tab, the wheel became really hard to turn. If I release the pressure on the wheel, it turns freely but as soon as I clamp it up it becomes hard to pedal.

Im unsure if there are bearings in the hub or what the mechanicals are in there, I thought I'd see if anyone knew if this was a common problem/easy fix before I asked the bike shop to look at it.

Anyone got any ideas?!

Cheers,

Sam

 

[Fiona N]

Apologies if you've checked this already but could it be that when you clamp the wheel, you move it out of alignment so that the rim rubs on the brake blocks. That's often a problem apparently with brake alignment. You need to pull the wheel axle back into the drop-outs firmly as you close the clamp up otherwise there's a tendency for the force applied to slip the axle slightly out of the clamp side of the drop-outs which means the wheel doesn't spin precisely in the plane of the bike frame and impinges on the brakes blocks to a greater or lesser degree.

 

[eldudino]

Hi Fiona,
The brake definitely isn't binding. Having just put new pads in, I wound the calliper out fully, pushed the wheel all the way into the drop-outs, did it up tightly and tried spinning the wheel. It does spin but comes to a halt very rapidly. It's almost as if the drop-outs are applying pressure on the axle and causing a bearing carrier to clamp up.
S

 

[PpPete]

Sam
Did you service the hubs or adjust the cones at all? Q/R will squeeze them a little tighter, so what was good off the bike may be too tight when back on bike.

 

[eldudino]

Pete, I didn't touch the hubs. Just took the wheel out and put it back in. It was a problem that pre-existed. I've never stripped a bicycle hub before, might it be worth taking the thing apart and checking I've not knackered anything inside? I'm fairly heft so could it be a weight issue?!

 

[RedBike]

In theory (If the wheels correctly adjusted) then no matter how hard you tighten the quick release it shouldn't really have any noticable effect on how the wheel spins.

Although designs of wheels differ there's normaly two locking nuts on each end of the axle. Inside of these nuts is a a few seals to stop the water getting in then a cone that applies pressure on the bearings.

When you tighten the quick release it pushes the frame tight up against these outer locking nuts. It doesn't push up directly against the cone nuts or the bearings.

Because of the large forces involved it's normal for the axle to be compressed slightly / these nuts to move ever so slightly. We're only talking fractions of a mm but thats all it takes for the bearings to go from perfectly adjusted to being over-tight.

Check that the nuts on either side of your hub are tight and there's no play in the axle (you can't wobble the wheel). If everything seems right then it's reasonable to assume that nothings moved and everything is still correctly adjusted.

Have a look at this.
http://steveukmtb.wordpress.com/shimano-hub-overhaul-cup-and-cone/

 

[eldudino]

Thanks Redbike, I took the wheel off and there was plenty of play in the axle so I tightened up the locking nuts so that they pinched the bearings then unwound by a couple of degrees to release the pressure off them and it's made the world of difference. The bike's currently freewheeling fantastically and I also noticed that the rear derailleur was rubbing on the chain. I'm not happy with the rear derailleur as it seems to lose its settings really easily. It's an Alivio and I'm wondering whether a better model would be more robust?

 

[RedBike]

I took the wheel off and there was plenty of play in the axle so I tightened up the locking nuts so that they pinched the bearings then unwound by a couple of degrees to release the pressure off them

Make sure you loosen the inside nut while tightening the outside nut so that they 'lock' together and will not come loose.
If you've been riding your bike around with the cone nuts loose there's a chance you've damaged the bearings. If the wheel starts to feel rough /notchy then get the bearings changed and the hub re-packed with grease before anymore damage is done.

I'm not happy with the rear derailleur as it seems to lose its settings really easily

At this time of year your gear cables are probably clogged up with muck which wont be helping. A new gear inner cable is only £2/ £3 so it's worth taking a punt on fitting a new one to see if this helps before splashing out a new rear mech.

 

[mickle]

A wee trick for assessing bearing condition; hang the bike up or put it in a workstand, spin a wheel and then press your temple onto the saddle. You'll actually hear the bearings as the noise travels through the frame and passes into your skull. Scary sometimes because what appears to be a freely spinning wheel can be making the most godawful grinding noises if the bearing surfaces are shot. It works on the BB too but you have to unhook the chain and also on the headset to an extent.

 

[mickle]

Unhooking the chain from the cassette removes the freewheel mechanism from the equation so you can hear the wheel bearings btw.

 

[eldudino]

Cheers for the replies guys. I'm going to strip the hub and check for signs of wear, re-grease and re-assemble.

Redbike, my hub seems only to have one nut, not two with one to lock to as I would normally expect to see. I'll check it out when I strip it at the weekend.

 

[fossyant]

It will have one lock nut, but that tightens, with spacers onto the cone - you'll need cone spanners - (thin spanners) one on the cone, and a standard spanner on the lock nut

 

[RedBike]

Redbike, my hub seems only to have one nut, not two with one to lock to as I would normally expect to see. I'll check it out when I strip it at the weekend.

As Fossyant pointed out there are two. Your hub uses the cone itself as a 'lock nut'. You'll need a narrow spanner (cone spanner) to get at it though.

 

[andrew_s]

A QR will push hard enough to cause bearings to go out of adjustment - the axle gets compressed slightly. One of the problems with adjusting standard cup and cone hub bearings is judging how loose to leave them to allow for the tightening as you do up the QR.
It's quite likely they have been tight for a while - you might find you've suddenly got fitter once they are properly adjusted.

 

[Mr Pig]

One of the problems with adjusting standard cup and cone hub bearings is judging how loose to leave them to allow for the tightening as you do up the QR.

Yip. Sometimes takes a couple of goes to get it right. Just leave a tiny bit of play in the bearings for the QR pressure to take up.