Weird freehub behaviour

[winjim]

On my ride today I had my freehub jam up. I had just ridden through a particularly dirty bit of road where there had been some logging going on (which may of course be coincidence) when suddenly my foot was unclipped and I was toppling from the bike. A bit of investigation revealed that the cassette/freehub was stuck fast and wouldn't freewheel at all.

I managed to get most of the way home riding pseudo-fixed, meaning some hilarious high cadence descents, then I went over a bump, felt something go clunk, and my freewheeling ability returned!

When I have time I will be stripping the hub down completely but I just wondered has anyone had had this happen, and any provisional ideas what the problem could be?

 

[Yellow Saddle]

It is very common. The opposite is when it doesn't engage at all. That way you don't fall, but you still walk home.

 

[fatboy123cycling]

The pawls inside the cassette will have ' stuck' in the open position - there are two pawls - which are normally 'open' to give you drive. When you freewheel they run freely against the spring pressure. It needs flushing out and a re - lube

 

[zacklaws]

If its a Mavic, they are renowned for it......but when they go they squeal

 

[winjim]

It's Bianchi branded so made by Miche maybe?

 

[winjim]

I've got the wheel apart, and the freehub appears to have disintegrated. These three bits of metal have broken off from just behind one of the pawls.

Is that common? Because although the bike is four or five years old, it was in storage for most of that time so has only really been in use for a year, and not very heavy use at that.

I guess it's new wheels time

 

[Andy_R]

Not new wheels time, just new hub. Get your LBS to replace the hub for a fraction of the price of a wheel (unless they are cheap as chips wheels)...or even take the opportunity to practise the black art of wheel building - you aren't going to make anything more broken than it already is and you could learn a new skill and become a wheel building guru for the rest of us to bow down to.

 

[Yellow Saddle]

I've got the wheel apart, and the freehub appears to have disintegrated. These three bits of metal have broken off from just behind one of the pawls. View attachment 80366 View attachment 80367

Is that common? Because although the bike is four or five years old, it was in storage for most of that time so has only really been in use for a year, and not very heavy use at that.

I guess it's new wheels time

Not common at all. Usually the pawl recess (that bit where the pawls live and which on your photo broke in half) wears to become larger and causes sloppy engagement but I've never seen them break out like that.
Here's a photo of a typical freehub that's worn. The old one on the left, new one on the right. You'll see that the cavity wears backwards, as you would expect.

The way I see it, the only way it can break as in your photo, is for the pawl to actually open beyond it's engagement point, which could indicate that the ratchet ring on yours is broken or cracked.

 

[winjim]

Not new wheels time, just new hub. Get your LBS to replace the hub for a fraction of the price of a wheel (unless they are cheap as chips wheels)...or even take the opportunity to practise the black art of wheel building - you aren't going to make anything more broken than it already is and you could learn a new skill and become a wheel building guru for the rest of us to bow down to.

Well I have been meaning to get into wheel building, but family situation means I have very little time for riding, let alone learning a new skill. Maybe it's time to start.

The way I see it, the only way it can break as in your photo, is for the pawl to actually open beyond it's engagement point, which could indicate that the ratchet ring on yours is broken or cracked.

I didn't properly check the ratchet ring before I reassembled the hub (for tidyness, I don't intend to ride it) but that makes sense. I'll take it apart again and have a proper check some time.
I have to say I'm a bit disappointed. It's not a top of the range hub or anything but it is a stock wheel on a reasonably high end bike and it can't have done more than about 1500 miles, although as I say it is 5 years old and I am not the original owner so I don't think I can claim on warranty or anything. Oh well, I shan't be buying any more Miche products.

 

[Yellow Saddle]

Well I have been meaning to get into wheel building, but family situation means I have very little time for riding, let alone learning a new skill. Maybe it's time to start.

I didn't properly check the ratchet ring before I reassembled the hub (for tidyness, I don't intend to ride it) but that makes sense. I'll take it apart again and have a proper check some time.
I have to say I'm a bit disappointed. It's not a top of the range hub or anything but it is a stock wheel on a reasonably high end bike and it can't have done more than about 1500 miles, although as I say it is 5 years old and I am not the original owner so I don't think I can claim on warranty or anything. Oh well, I shan't be buying any more Miche products.

It is not only Miche. Those pictures I showed you was from a PowerTap hub which is a pretty expensive power meter hub. The wear was also premature and in spite of all my evidence, measurements and careful photography, the distributed claimed it was due to abuse of sorts. How do you abuse a freehub by using it for what it was intended. Later on, I found the same problem on another hub but this time it was branded Novatek but exactly as the ones on the photo. Powertap thus uses a Novatek hub, so I avoid those as well.

 

[MattEllis]

I have just come across the same problem only mine was after fixing a puncture.
I left it a few days after a muddy ride home from work & the chain rusted a n
Bit.
I have given it a good clean and lube but can rust cause the freewheel to stop working?
I'm giving it a bit of time to settle before I try it again.