Chain slipping when shifting

[nishikibike]

My old nishiki bike was having some troubles with the chain, when I pedaled hard it would slip and gear shifting was rough so I inspected it and found a seized link and replaced the chain. When shifting (non indexed shifter) sometimes if I'm not being careful the chain will go between 2 gears and spin freely when shifting to a lower gear. My assumption is that my rear freewheel/cassette needs to be replaced, is this the case or is it possible that I did a poor job adjusting the derailleur?

[DaveM]

The "going between" could be a sign that you got too narrow a chain. If you have a 6 speed cluster and got a chain made for 9 speed for instance, it would be very narrow.

If you have non-index shifting, most likely you have a freewheel. These tend to last a lot longer than cassettes. But if it still slips when you put a heavy load on the pedals, I'd change that too.

Freewheel or cassette?
http://sheldonbrown.com/free-k7.html

The slipping under heavy pedaling though is often a sign that the chain and cassette are both worn. It's often advised to change both at the same time unless you know one is quite new (especially on cassettes). So it may make sense to replace the cluster regardless.

[nishikibike]

(09-05-2014, 05:17 PM)DaveM Wrote:  The "going between" could be a sign that you got too narrow a chain. If you have a 6 speed cluster and got a chain made for 9 speed for instance, it would be very narrow.

If you have non-index shifting, most likely you have a freewheel. These tend to last a lot longer than cassettes. But if it still slips when you put a heavy load on the pedals, I'd change that too.

Freewheel or cassette?
http://sheldonbrown.com/free-k7.html

The slipping under heavy pedaling though is often a sign that the chain and cassette are both worn. It's often advised to change both at the same time unless you know one is quite new (especially on cassettes). So it may make sense to replace the cluster regardless.

I put a 7/8 speed chain on my 6 speed cassette, the person at mec said it should be fine, is it?

[DaveM]

(09-05-2014, 05:30 PM)nishikibike Wrote:  I put a 7/8 speed chain on my 6 speed cassette, the person at mec said it should be fine, is it?

I think technically it is yes. You might look at how the chain sits on the gear teeth. If it doesn't drop completely into the valley of every tooth equally and rides up on the side of some teeth, that could be a sign the cluster is very worn and a new one would improve things.

Different freewheels also have different gaps between cogs. Could be you have one with wider gaps and that it would work better with a 5-speed chain.

If you post the exact make (and model if known) of everything you have, someone might have more specific advice. Sorry I can't give you a firmer answer.

[cny-man]

Going between gears has nothing to do with derailleur adjustment on a friction shift, as the only adjustment is at the two ends (an b-tension). You should check to make sure the cable is running freely, especially if the slipping occurs when going to smaller cogs - the derailleur spring does the shifting, and must be able to easily pull the cable through the housing. If there's binding you may be caught between gears.