Weird freehub problem

[jefmcg]

I cycled home no problem on Thursday night and parked my bike. When I got it out on Friday morning and tried to pedal and nothing happened. I pedalled and the pedals spun freely, but didn't move. I thought the chain had come off, but no.

So I took the wheel off, and found I could hold the cassette and spin the wheel in either direction - my free hub was really free. So I removed the cassette, and held the splines, and everything seemed fine. So I put the cassette back on and everything was working correctly again!

Anyone have any clue what happened? I am committed to leading a group tomorrow, and have to take this bike. No time to get to a bike shop today, but I can poke around this evening or tomorrow morning if it may help. I can't understand what happened, or whether it will happen again. The fault occurred while it was sitting unmolested in the corner of my kitchen.

Anyone have experience of something like this? Suggestions are welcome.

Thanks

(if I do have a problem on the ride, it's not a complete disaster: I'll be able to limp home and they will manage without me, but obviously this is not desirable. Oh, and if the fix is a new build or rebuild, that means I will want to look at IGH, so that's a big project.)

 

[accountantpete]

It's down to the pawls. When the wheel turns one way they fold down on top of a spring to allow free movement.

When the wheel turns the other way they spring up and engage with the hub.

What has happened is either gunk has gotten into the works and is stopping them springing back up or the spring has gone.

Here's a pic -some freehubs just have one spring for the 3 pawl others have cloiled springs - but it's the same principle.

 

[PpPete]

Pawls....
Problem more often seen in cold weather on old freewheels. The grease would get hard and stop the movement of the pawls. Old school road-side fix was to piss on the freewheel. Not likely to work on modern freehub though.

 

[jefmcg]

Brilliant! A "lump" of something fell out, so that explains the fix.

Skip the pods solution for obvious reason.

Thanks

Joan