free hub issues again

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mattsccm
Posts: 3415
Joined: 28 Nov 2009, 9:44pm

free hub issues again

Postby mattsccm » 13 Sep 2020, 10:02pm

:roll: This hub has made an appearance here before. Its a Chosen thing with a freehub that pops off in your hand once the end cap is unscrewed. 3 pawls running in a very fine toothed steel insert in hub. It sticks occasionally .Tried it slathered in grease to just about greasy enough to mark your best white shirt. Makes no difference. Put up with it until it wrapped the chain around the mech and snapped the mech hanger so to teach it a lesson I popped as new hub in the wheel.
But why does it do it? Immaculate inside. Pawls held in by a wire ring around them with a hooked end that fits one of 3 holes. Maybe this is the issue. Do you reckon the hook end should lead or follow? Other end just is an end.

gregoryoftours
Posts: 1286
Joined: 22 May 2011, 7:14pm

Re: free hub issues again

Postby gregoryoftours » 13 Sep 2020, 11:21pm

A collegue looked at a rear wheel for a customer the other day, the freehub felt completely free out of the frame. It turned out to be a slightly displaced seal on the back of the freehub that was causing the binding when clamped in the dropouts. Could be this, or perhaps a cartridge bearing in the freehub that is damaged inside such that it jams up sometimes, or is ill-fitted, causing it to bind when clamped? From your description it doesn't sound like the ratchet is necessarily the cause.

mattsccm
Posts: 3415
Joined: 28 Nov 2009, 9:44pm

Re: free hub issues again

Postby mattsccm » 14 Sep 2020, 7:11am

Tried it without a seal. Same thing. I'll have a close look at the bearings, all look good though. Thanks

Brucey
Posts: 40650
Joined: 4 Jan 2012, 6:25pm

Re: free hub issues again

Postby Brucey » 14 Sep 2020, 10:52am

IME thick grease can 'drag' the pawls out of their seats when freewheeling and this will cause a jam. The spring tension needs to be exactly right too.

IMHO an arrangement like that can more easily go wrong when there are three or more pawls on one spring than if there are just two (as in a shimano or shimano-esque freehub). The reason is I think that when three pawls are depressed, the spring is more likely to lose contact with one of the pawls altogether, which can lead to dragging and jamming.

So I suggest a new spring and thinner lube in the pawl mechanism as things to try.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

mattsccm
Posts: 3415
Joined: 28 Nov 2009, 9:44pm

Re: free hub issues again

Postby mattsccm » 14 Sep 2020, 12:30pm

Good point. Not considered that outer spring thing.