Centre lock brakes question

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Scunnered
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Joined: 11 Apr 2014, 11:23am

Centre lock brakes question

Postby Scunnered » 21 Feb 2020, 1:36pm

I have some new DT Swiss wheels which take centre lock disc rotors. The rotors fit on the hub easily but when I finger tighten the lockring, the rotor is still loose. I know the lockring is supposed to be tightened further, but it seems to me that the thread on the lockring is deeper than the thread on the hub.
Is this normal?
Should I just tighten the lockring until the rotor is tight, or will that just damage the threads?

thx

reohn2
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Joined: 26 Jun 2009, 8:21pm

Re: Centre lock brakes question

Postby reohn2 » 21 Feb 2020, 1:38pm

Is the lock ring tightening or bottoming out on the threads with the rotor still with excessive play?
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Scunnered
Posts: 224
Joined: 11 Apr 2014, 11:23am

Re: Centre lock brakes question

Postby Scunnered » 21 Feb 2020, 1:49pm

reohn2 wrote:Is the lock ring tightening or bottoming out on the threads with the rotor still with excessive play?


That is what I think is happening.

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RickH
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Joined: 5 Mar 2012, 6:39pm
Location: Horwich, Lancs.

Re: Centre lock brakes question

Postby RickH » 21 Feb 2020, 2:13pm

I think (it's been several years since I removed the discs on my Circe which has centerlock discs) there are ridges & grooves, the same as with a Shimano cassette & lockring. By my reckoning, you will never manage to get the lockring anywhere tight enough just with your fingers. I would suggest trying to do it up properly (but without excessive force) with a lockring tool & seeing if it seats properly.

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Centre lock brakes question

Postby Brucey » 21 Feb 2020, 7:44pm

suggestion; fit the lockring without the disc and see how far it goes. Compare the remaining gap between the lockring flange and the hub shoulder with the corresponding thickness of the disc hub.

I suspect that because the lockring and the disc centre are serrated, you won't get the disc held securely by finger tightening the lockring, and that simply tightening the lockring will resolve the problem. However if you do the suggested check first, you can be certain that you are not making a problem for yourself.

cheers
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Scunnered
Posts: 224
Joined: 11 Apr 2014, 11:23am

Re: Centre lock brakes question

Postby Scunnered » 24 Feb 2020, 12:56pm

I was just being over-cautious, not wanting to damage my new wheels!
The measured depth of the thread on the lockring was a few mm less than the recess in the hub, so the problem existed only in my imagination.
With the lockring tool connected to a 1/4" handle, there was no problem tightening the lockring.
Thanks for all the advice.