Rear mech for 12 speed bike

[RobThompson1]

I have broken the rear mech on my bike. It's a 1990s Peugeot Performance 100 (cheap racer). It's only a 12 speed bike, so 6 speeds at the back.

Sorry for being thick, but my question is this. 6 speed rear mechs don't seem to be available any more. All the rear mechs currently on sale are 8, 9 or 10 speed. Would that work with 6 speed? Or not?

Thanks,

Rob

[PW]

You can't get 6 speed chains either. The manufacturers expect 6 speed users to use the 8 speed chain, so I'd assume the 8 speed mech will go with it. If it has downtube friction levers there shouldn't be any indexing compatibility problems.

[RobThompson1]

Ok, thanks for your help. They are downtube shifters but it is indexed. Does that make a difference?

[drossall]

Try the Shimergo page. Covers what works with what pretty comprehensively.

Not sure what you mean by does it make a difference. It's not relevant that they are down-tube shifters - not sure you could get 6-speed STIs, but for the same number of speeds (and manufacturer) any lever type has to pull the same amount of cable. Non-indexed will work with any mechanism of course because you just move the lever till the gear is in the right place relative to the sprockets - but your gears are indexed.

[RobThompson1]

Ok, that's very helpful. Thanks.

[gaz]

.

[bigjim]

My lbs replaced the original campag 6 speed rear mech on my raleigh for a shimano 6 speed with a better granny. no problem. So they must be available.

jim

[drossall]

If you're talking 6 speed, it's probably non-indexed. So any gear mechanism would do within reason, including those designed for indexed, except perhaps the latest 10-speed that won't take a wide enough chain.

[djnotts]

The rear mech doesn't know how many sprockets it is operating (in almost all cases indexing is in the shifters, not the mech). I suppose the cage/jockey wheels on a 10 speed rear mech might not accept a 5 speed chain because of the thicker side plates, but apart from that usually the stops will sort any 5/6/7/8/9 problems.

[byegad]

To avoid indexing problems a seven speed mech will work on a six speed cassette. Eight speed MAY work but getting a decent change at both ends, 1st and sixth gears, may be a problem

[PW]

If it's a Shimano mech the geometry is the same for all bar some very old Dura Ace which you won't find anymore. The compatibility problem arises from the shifters and the sprocket spacing. If the chain goes through the cage plates the mech will work fine.

[dewi1]

Try this. Note it has no hanger.

http://www.ukbikestore.co.uk/product/pr ... p=0&gclid=

[wheelsmith]

how about the shimano rd-2200 in short cage, then fine tune it with tacx jockey wheels (adjustable spacers)

[Oldman]

On the same subject: I have a 1987 6-spd Maillard block and a much more modern (short cage) Chorus 9spd mech which I'd like to use together (giving 12 speeds). The Chorus is modern enough to be used normally in an indexing setup but I have the kind of shifting levers that can be used as friction or indexing to choice. If I use the levers in friction mode, will the mech simply clunk happily from sprocket to sprocket without indexing? ie, is it only the lever that makes the difference rather than the design of the mech?