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Re: noise from cassette

Posted: 8 Aug 2019, 2:07pm
by Brucey
if a freewheel mechanism has multiple pawls (some DT hubs don't BTW, they have a different mechanism and I don't remember if yours is like this or not, I'm assuming not) then it is always possible for one pawl only to engage or to have all the pawls other than one engage fully. When this happens badly engaged pawls pop out and there is a huge side load on the parts that shouldn't normally exist. Either (or both) of these things can make a noise.

What normally happens is that after a period of running the parts bed in and (with any luck) the pawls become more likely to engage properly.

Unfortunately the things that folk say they prefer (such as minimal backlash and easy freewheeling) are exactly the same things that mean that inconsistent pawl engagement becomes more likely.

In your case I'd recommend adding some oil mixed with grease (a kind of ersatz SFG (semi fluid grease) if you like) to the pawl mechanism, having examined it for any damage. Improved lube will make for quieter freewheeling and more consistent behaviour during engagement.

cheers

Re: noise from cassette

Posted: 8 Aug 2019, 2:33pm
by Ray
Thanks, Brucey, that sounds a reasonable explanation for the noise.

I'll try and examine the pawl mechanism this weekend (doesn't look like summer bike weather :( ) and add some lube. Any reason not to use yer' actual SFG? I've got a Halfords aerosol can in the garage.

Re: noise from cassette

Posted: 8 Aug 2019, 6:18pm
by Brucey
if it is SFG it will probably work OK, the only thing is that in an enclosed space such as a pawl cavity it may take longer than you expect for the solvent to flash off.

cheers

Re: noise from cassette

Posted: 8 Aug 2019, 8:14pm
by Ray
Thanks again. Will explore it in the next day or two. Having checked in the garage, I find that the Halfords aerosol does not, in fact, specifically claim to be SFG - here it is : https://www.halfords.com/motoring/engin ... ease-500ml

It's useful stuff for hinges, garages doors and the like; easy to apply, not too thick for those purposes, but maybe best 'diluted' with a bit of oil for freewheel pawls ?

Regards

Re: noise from cassette

Posted: 8 Aug 2019, 8:43pm
by Brucey
if it is as I suspect, don't use it; a lot of aerosol greases dry out and leave a chalky deposit after a while, which is worse than useless.

cheers

Re: noise from cassette

Posted: 8 Aug 2019, 8:56pm
by Ray
Thanks, Brucey, will avoid it. Have now found some DT Swiss servicing videos, which make the job look reasonably simple; I hope!

Re: noise from cassette

Posted: 9 Aug 2019, 4:34pm
by Ray
OK, examined the pawl mechanism, which looks fine and robust, and added some oil/grease lube as recommended. A quick spin round the block and all seems fine, including a very worthwhile reduction in noise. I'll need a few hours on it to be absolutely certain the clicks and cracks don't reappear, but it's reassuring to have peered into the innards, and therefore to know what I am dealing with.

Thanks, Brucey.

Re: noise from cassette

Posted: 9 Aug 2019, 8:29pm
by Brucey
let's hope it isn't just a flash in the pan

cheers

Re: noise from cassette

Posted: 9 Aug 2019, 8:52pm
by NATURAL ANKLING
Hi,
Is that with a new wheel?

Re: noise from cassette

Posted: 9 Aug 2019, 8:53pm
by Ray
Yes.

Re: noise from cassette

Posted: 9 Aug 2019, 9:23pm
by NATURAL ANKLING
Hi,
I know sad old git Brucey (his words not mine :lol: ) says he does not rate lube in modern freehubs but I would be very disappointed with a new wheel sounding like that.
I have old never touched freehubs that keep on going, I rarely take the things apart, but have, just normally swap for another better used one, but I do my style means I do not coast much :)

Re: noise from cassette

Posted: 9 Aug 2019, 9:39pm
by Ray
The loud tick of the freewheel is a characteristic some manufacturers make no effort to avoid; indeed it almost seems that they make it a selling point. These wheels came with the bike spec., and I am ready to accept them, even though I generally prefer the blessed silence of Shimano. Adding some grease seems to tone down the noise, which is welcome. As for the clicks and cracks, as long as there is no long-term damage, now that I understand what is (probably) going on, there is no cause for alarm. It will be interesting to see whether the extra lube, plus a 'running-in' period will make for a quieter life.

Heading out east from home I hardly need to freewheel - it's pretty flat, and I glide along in a whisper. Heading west, direction Holmfirth and the hills, is a different matter :)

Re: noise from cassette

Posted: 18 Aug 2019, 5:25pm
by Ray
Ray wrote: I'll need a few hours on it to be absolutely certain the clicks and cracks don't reappear,

Over 100kms up hill and down dale now since lubing the hub. It's certainly a lot quieter and, while I hesitate to speak too soon, there's been no clicking/cracking when starting or when resuming pedalling. Seems like the job's a good'un.

Maybe DT Swiss should have prepped the hub better in the first place?