occasional chain slip on 2 new setups

chatlow

Recently rebuilt two bikes with an almost identical setup and ever since finishing them, I've noticed they both, occasional slip. Most of the time it happens when i've just changed gear or been freewheeling a while and then start pedalling.

Just finding a bit weird that both are doing it, so assume it could be down to the new but similar components:

1st bike: Tiagra 10 speed chain, Tiagra 4700 11-28 cassette, 4700 RD and shifters.
2nd bike: KMC x10 speed chain, Tiagra 4700 11-28 cassette, 105 RD and shifters.

Chain is a perfect fit so only thing I can think of is the Tiagra cassette.

This likely to be a new thing?

keef66

Can't imagine what's wrong with either bike unless there's a stiff link in the chain. Was it joined using a Shimano snap-off joining pin? Or a KMC Missing Link? Is the pin properly installed? Is the link the correct speed? Is the chain the right way round?

dee4life2005

If the rear derailleurs aren't new ... a possibly sticky jockey wheel cage pivot spring?
Although you'd be unlucky to get both with symptoms at the same time.

chatlow

keef66 wrote:

Can't imagine what's wrong with either bike unless there's a stiff link in the chain. Was it joined using a Shimano snap-off joining pin? Or a KMC Missing Link? Is the pin properly installed? Is the link the correct speed? Is the chain the right way round?

Well 1 has KMC which use a missing link and the other is shining which use a joining pin. All links seem good though.

Oh and KMC isn't directional but yes the shims no chain is correct way around.

To be clear, this isn't a full slip that I get, it's more a clink and feels like one ore two teeth slip into place

bbrap

Are you sure it is actually the chain slipping? I know its unlikely as both bikes are doing it but could it be the freewheels? As you have re-built both bikes did you use grease or light oil in them? I'm thinking if you used a heavy grease that after freewheeling it may take a second or so for the pawls to drop back and engage making you think the chain is slipping. I'd redo one of the freewheels and then see if it improves things on that bike.

Bobbinogs

^^^ Sounds like a very good suggestion, particularly given the nature of when the slips occur.

chatlow

bbrap wrote:

Are you sure it is actually the chain slipping? I know its unlikely as both bikes are doing it but could it be the freewheels? As you have re-built both bikes did you use grease or light oil in them? I'm thinking if you used a heavy grease that after freewheeling it may take a second or so for the pawls to drop back and engage making you think the chain is slipping. I'd redo one of the freewheels and then see if it improves things on that bike.

forgot to mention.. both bikes have bran new wheelsets! One has Campag Zonda's, the other Fulcrum quattro.

The mystery continues...

bbrap

OK, lets have another think. Happens on both bikes which have been re-built. New (but different) wheels, chain, mech etc all seem OK. How about something stupid like one of your cleats being a tad loose and moving back into position once you put the pressure down? I'm thinking that maybe its something which is transferred to each bike (eg, shoes, cleats). Probably bonkers but as you say "the mystery continues".

dinyull

Are you sure it's chain slip?

I've just built up a bike using Tiagra 4700 and having a similar problem - although I'm pretty sure it's the gear indexing. The screws are set correct on the inner and outer cogs but in the middle the indexing is slightly out meaning a bit of jumping about on the cogs that feels like slip.

Because it wasn't a brand new rear mech I'm assuming there's a bit of crap stuck in the spring so gonna wash it out this weekend and see where that gets me.