Chain Slipping

[martint235]

Ok I have asked this question in another place and received some helpful answers so if you have contributed on YACF, please don't think I'm discounting your answers, it's just the more opinions I have the more chance I have of fixing things.

So to the problem. My chain slips. It started last Saturday and seems to happen primarily, although not exclusively, after a period of freewheel. It has happened whilst cruising at about 20mph but has never happened whilst sprinting or climbing (although I haven't done much sprinting in case it does happen). So far the suggested issues regard the chain itself or the freehub (Shimano 105). Over the weekend I'm going to:

1. Take the chain off the bike completely and give it a bath in degreaser.
2. Take the wheel off and try spinning it using the freehub to see if it ever slips.

Does anyone have any other ideas? Thankfully this hasn't happened during the busy century riding season as I'm not going any long distance on it until it's sorted. Had a freehub fail before and I had to walk home!!!

TIA

 

[RecordAceFromNew]

Chain slip can mean various things. If it was me the first thing I would do is to lift the back wheel off the ground while trying to simulate the "slip" and try to see what actually happens.

If the chain remains engaged normally on the cassette when it "slips" then it is the freehub not chain slipping. This is quite likely in your case since the pawls are only depressed when freewheeling, then you might have to service/replace your freehub.

 

[martint235]

Chain slip can mean various things. If it was me the first thing I would do is to lift the back wheel off the ground while trying to simulate the "slip" and try to see what actually happens.

If the chain remains engaged normally on the cassette when it "slips" then it is the freehub not chain slipping. This is quite likely in your case since the pawls are only depressed when freewheeling, then you might have to service/replace your freehub.

It's difficult to tell. I can't replicate it on a stand or lifting the wheel off the floor. So unfortunately all I have to go on is the sensation of a judder through the pedals that seems to equate to a slip in the chain. Without being able to see what is actually happening this could be freehub (which I'm now inclined to think) or chain. I'm 99% certain it's not the cassette itself.

Freehub on order.

 

[Broadside]

Slipping after freewheeling will almost certainly be due to a freehub problem with the pawls sticking in the open position.

At this time of year it could be due to temperature drop making the grease more solid and sticking them open, or it could just be general dirt that has got in there contaminating the grease and reducing its effectiveness. Or there might be no lubrication in there and it is starting to corrode.

 

[yumpy]

You could just buy a chain, which could be a spare anyway for future and put that on. If problem goes, then it was the chain, if not its probably the freehub.

That's the 'car-dealer' method. Stick in a new one and if the problem goes away, bill the customer

 

[martint235]

You could just buy a chain, which could be a spare anyway for future and put that on. If problem goes, then it was the chain, if not its probably the freehub.

That's the 'car-dealer' method. Stick in a new one and if the problem goes away, bill the customer

Chain and cassette are only 500 (relatively dry) miles old.