Freewheel locks up when skewer is tightened?!

[Fatal Swan]

I haven't come across this issue before but it must be something obvious... I've had this bike working for a couple of short rides and when I've come to use it today I noticed that it wouldn't back-pedal at all when I went to oil the drivetrain. Also really rough moving it forwards. Upon inspection it all seems to be working nicely until I tighten the skewer, at which point the freehub stops turning backwards altogether with loads of friction turning forwards. The setup is:

Novatec CXD wheels that are <50 miles old, bought new in January. 11s Shimano freehub
10 speed XT 11-32 cassette, with the spacer fitted at the back
Wheels set up for 135mm QR (same issue regardless of the QR I use, including an allen bolt type)
Disc brakes, but they're spinning fine with no rubbing so it's definitely ot that

I can't think what else to try - once I get the chance I'll see if I can swap some wheels/cassettes around, but anything I'm missing? Am I right to suspect a freehub which is virtually new?

Cheers!

 

[Woz]

Cassette / chain hitting the inside of the DS drop-out would be an obvious one.

In all honesty though, your set-up is too modern for my competence. It's like Space X compared to what I am wrenching on.

 

[d8mok]

Have you tried it without the spacer?

 

[Fatal Swan]

Cheers! Doesn't seem to be a clearance issue with the dropout, but I will confirm...

And I'm almost certain I've fitted the 10s cassette without the spacer when it arrived and it wouldn't tighten without play, but there's two things for me to check in the morning, thanks!

 

[Woz]

What can happen sometimes, but it is a different symptom really is that depending on the freehub and depth of the lockring, the lockring can be inserted too far in the freehub and foul with the dust seal. You only notice this though free-wheeling; the freehub want to always turn with the wheel.

Finally, broken axles can be weird - sometimes you only notice when the QR skewer is completely removed.

 

[Fatal Swan]

Right, some progress (in a way), I think I've managed to rule out a few things. What happens is that once the axle clamps against the inside of the dropout, the fixing of the axle in position in the dropout stops the freehub from turning. So when you turn the cranks backwards, the cassette doesn't move and the chain just jams...

Firstly, it's definitely not a lockring/sprocket clearance issue. Nothing external is rubbing where it shouldn't.

It doesn't seem to be a quirk of the cassette. I've replaced the Shimano 10 speed one with a SRAM 8 speed model and it's exactly the same.

It doesn't seem to be the frame, or my hapless attempts at installing a rear wheel. I've stuck on the only spare 135mm wheel I have to hand, tightened it up and the freehub works just like it should with the above cassettes - turning the cranks backwards makes the cassette spin backwards.

So as far as I can tell that means it has to be the freehub on the wheel. Which is certainly odd as it's a £400+ wheelset that's had <50 miles of use on the road. Last thing to try is to remove the 8/9/10 speed spacer just to make sure.

 

[Woz]

Nothing external is rubbing where it shouldn't.

After some wine and intense lateral thought, I think your hub / free-hub is sadly FUBAR too.

Worth getting the vendor to sort it out if under warranty, let them have the head-ache.

Sadly, price paid is no real measure of quality in the cycle industry. Sometimes designs are flawed but the product still hits the market place.

 

[drystonepaul]

Sounds like the axle spacer between the drive side hub body bearing and the freehub body could be missing or damaged.
Could be a damaged or dislodged pawl in the freehub mechanism.
Could also be to do with the seal between the freehub body and hub.
I've seen all these things cause the symptoms you describe on Novatec and other similar hubs before.

Difficult to determine without seeing the hub.

 

[Fatal Swan]

Thanks everyone - looking like hub internals is the culprit so a return under warranty - not a great sign for wheel that's 2 short rides old...

 

[Fatal Swan]

I've been dismantling the axle/hub assembly with the retailer's blessing to see if I can make any headway myself before it goes back (as a wheel/freehub/axle/etc). It's basically like this hub:

So what happens is that when you turn the axle, the freehub just turns with it, like they're locked together. When you dismantle it there's really not much to see going wrong. It all looks clean, in good order, factory grease still fresh etc.

When the non-drive side end cap is loosened off, then the axle and freehub turn independently again, just as they should. But tightening up the end cap to not-even-finger-tight (let alone with the allen key) and the axle and freehub just lock up again. While the warranty claim is being processed I might try fitting the other axle/end caps for different diameters and see if that makes any difference, out of curiosity.