Freewheel Snapped-in-Two after servicing

[buddha]

Pulling away from junction (on a 1 in 5 incline) my single-speed freewheel snapped in two! The bit that snapped was the ring containing the teeth. I didn't bother retrieving it from the road as it then went under the wheels of a lorry and other traffic.

Anyway. The freewheel is (was) a cheapo one, like this though only 1 year old and looked strong and well made. In fact I serviced it, for the 3rd time, on Saturday - cleaned and greased. It looked to be in good condition. So I am stumped as to why it snapped.

The only thing I did differently was to use white lithium grease, rather than the blue Park grease I normally use.

Was it a fluke, or is lithium grease a no-no?

 

[tyred]

Very strange but I have found cheap SS freewheels to be poor quality in general.

Grease should have very little to do with it. These things shouldn't even need serviced in normal circumstances. The freewheel bearing carries no load and only turns when the bike is freewheeling.

 

[gbb]

Not the grease Budhha just the cheap quality of the freewheel.
Its not unknown...colleague of mine brought a sub £50 bike from a shopping channel ...the freewheel snapped on his FIRST ride.

 

[Zoiders]

Cheapies have cast teeth and not machined.

They break, the grease you used has no mechanical effect on the material of the teeth.

 

[screenman]

At that price I am suprised it lasted a year, you definitely got your value out of it.

 

[buddha]

Looking at what's left, the chain has stretched by over 1/2 an inch - since Saturday, and the pawls are still in place, though one is a little damaged! Which leads me to think that the freewheel 'jammed' internally > chain stretched > whatever was jamming the freewheel overstressed the sprocket-ring from the inside.

Looking at a similar freewheel, I wonder if I managed dislodge a bearing-ball when I serviced it , which caught under a pawl resulting in a stress point?

I know it's just a cheapo freewheel. But I am still surprised as the quality of the steel looked good (from what I remember in metallurgy lectures). Though I think I'll replace it with something better


I was cursing myself on the long walk home, having removed the fixed gear sprocket on the other side of the hub just last week! (it's a flip/flop hub on my pompino)

 

[buddha]

Cheapies have cast teeth and not machined.

They break, the grease you used has no mechanical effect on the material of the teeth.

The teeth didn't break, the whole sprocket snapped in two.

 

[Zoiders]

The teeth didn't break, the whole sprocket snapped in two.

The teeth are part of a ring that sits on the freehwheel body.

That ring includes the teeth.

It's a cheap one piece casting, castings are known to break.

 

[fossyant]

Cheap rubbish. Should have been riding FIXED anyway

 

[screenman]

Chain has stretched 1/2 inch in a couple of days, never heard that before. Never knew that a chain could stretch that far at all ,learn something new everyday.

 

[mattsccm]

Chains don't stretch they wear. Just a small chance that the total wear in say 110 link might add up to 1/2 " if they all suddenly were lubed up and the crud came out.
Anyway the solution is simple. Replace freewheel and chain. Freewheels such as Dicta's etc are rubbish and won't last long. I had one that was shafted in 500 miles and thats with lots of lube etc.
Bare minimum standard is a Shimano DX which can be found for 15 quid , maybe less. SS chains are cheap, under a tenner. Get hefty one. BMX chains are 1/8th " not 3/32nd and tend to last longer as everything is heavier.
They work perfectly well on SS. Chainwheel might be worn as well but I get 3 freewheels to a chain wheel so maybe not.