Rear hub tightening

This is probably the wrong forum to ak on, given it's a question about a geared hub, but it's the only one I frequent so I'll give it a go :)

I've got a dt swiss 370 rear hub (MTB / cartridge bearings). Once it's put in a frame and tightened in with the QR, the whole hub appears to tighten so much that the freehub / cassette can't move that freely and as a result doesn't take up chain slack when you try to freewheel - loads of tension gets put in the chain until it overcomes the freehub tension and 'snaps back'.

You can loosen the axle nuts, so that the QR doesn't tighten up the whole hub, but this doesn't sound good and will presumably make the wheel wobble around and interfere with the disc brakes.

I assume the freehub / bearings are screwed. Does anyone recognise these symptons?

Many thanks,

Chris

Maybe your cones are too tight? http://www.sheldonbrown.com/cone-adjustment.html

Thanks Stu - it's a cartridge hub, so no cones - there's a limited amount that could be wrong though and I imagine it must be something to do with the bearings being knackered. I'm off to the Alps on Wednesday, so I've left it a bit late to poke around / rebuild without having an idea of whats causing the symptoms!

Does the cassette freewheel OK on the axle when it's not in the frame, or if you attempt to make it freewheel by stopping the cassette does it still lock up? Have you tried removing the cassette & inserting the wheel into the frame & tightening to see if the freehub is still jamming?

Internet is suggesting a couple of potential causes:

Seized bearing inside the freehub boy, jamming the axle and freehub together [ame="http://forums.mtbr.com/showthread.php?t=472919"]DT Swiss 370 Info - Mountain Bike Review[/ame]

Crushing an aluminium spacer (if it's similar construction to other DT Swiss Hubs) [ame="http://www.ridemonkey.com/forums/showthread.php?t=237147#post3535222"]DT Swiss rear hub not free wheeling. - Ridemonkey.com[/ame]

There are a few things other things I can think of that might cause it, but none of them are particularly common.

Dirt/contamination/nasty broken stuff in the freehub body that is somehow stopping the pawls from retracting

Something jammed/wrapped around the freehub between the cassette and the spokes, which might be fouling them (hence the suggestion to take off the cassette)

Finally, a really bizarre one might be a broken axle? Sounds weird, but I was checking over a guy's bike who had a wobbly rear wheel, and the axle had actually snapped right in the middle. Only the QR skewer was keeping the cones (in his case) and everything in place. In your case the QR might be compressing everything up so much it's exerting lateral pressure, clamping down on the bearings. The wheel itself wouldn't spin well in that case, though.

Regardless, if you suspect the wheel might spontaneously and randomly convert itself into a fixed, rather than a free, wheel, I wouldn't ride it. That could get pretty nasty.

Thanks Mike, that's a very helpful post.

The cassette freewheels ok, then as you tighten the QR more and more the pressure on the hub gradually tightens until eventually the cassette will stop freewheeling. It's a bit of an odd one, it seems like the width of the hub is slightly (<1mm) too short so gets all squashed together; yet they've been on another bike previously (I bought them second hand, so I guess it's looking like they were knackered by the previous owner).

A bike shop mechanic reckoned it could be a cracked axle - seemed unlikely but I checked and it's not that.

I imagine something in the freehub must be messing it up; I took a quick look but it looks a little intimidating and I think life is too short to go trawling over a second hand, broken £40 wheel the day before hitting the Alps! Look like a paypal dispute and new wheel might be the easiest way out.

Thanks again for taking the trouble to reply.

No worries, if I were you I'd cut my losses and just get a new wheel at this point! Last thing you want is it crapping out on you halfway up (or down) a mountain.