Freehub disengages and then rengages — what is the issue?

Question

I have a Hope Pro hub and shimano freehub body with 11 speed cassette on my MTB. Recently when pedalling on occasion the resistance in the pedals disappears (like the chain has come off). It seems as through the freehub has disengaged. When I stop the freehub and pedals re-engage and I can continue for another few miles or so. It has only started happening recently ... never had this before.

Any idea what is happening. Do I need a new freehub body or do you reckon a service will do the trick?

Thanks all. I'll take the freehub off and take a look.

The thing that is odd (to me) is that I'll be pedalling and suddenly it will freewheel. There is no sound -- it is like the pawls suddenly retract ... i would have thought when pedalling it would have been hard / impossible to retract?

Go their site, they have video that shows how to remove the freehub so that you're able to inspect the pawls. Looks quite easy. — Carel, Jun 16 '20 at 09:10

score 4 · Answer 1 · answered Jun 16 '20 at 05:51

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Most likely pawls or other parts of freehub's engagement mechanism have become sticky. Opening it, cleaning it up and applying light grease (if at all) should help.

Much less likely but not impossible is that the pawls have become worn. Replacing them is then in order. In any case, servicing the freehub is the first thing to do.

answered Jun 16 '20 at 05:51

Grigory Rechistov

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I’ve heard that wear is much more likely if one continues to ride with slipping pawls since the slightly abrade and deform each time they slip under load. – Michael Jun 16 '20 at 06:05
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@Michael correct - it gets worse as time goes on. There's a certain adrenaline rush that comes when you're crossing an intersection from a dead-stop, and the pawls loose it, so you're drifting through the intersection on the momentum of your foot-pushoff. And there's traffic coming.... – Criggie Jun 16 '20 at 07:25
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Same on a big incline uphill and pushing hard on the pedals! – Carel Jun 16 '20 at 09:06

score 2 · Accepted Answer · answered Jun 19 '20 at 20:58

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Turns out that the freehub body had come loose from the rear hub when the cassette was changed. So it engaged most of the time but when it slipped out it was able to free wheel.

Took it off and gave a good clean and regrease and now all good

answered Jun 19 '20 at 20:58

John

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Freehub disengages and then rengages — what is the issue?

2 Answers2