Chainset Compatibility

[simont]

I am attempting to upgrade/liven up my 20 year old Dawes Super Galaxy. I've got Shimano 8 spd bar end shifters (front non indexed), HG70 11-28 cassette, sram chain and ultegra (double)front and (long) rear mechs. I want to fit a compact chainset but all those of similar quality to the other components (Centaur, Ultegra, 105) are 10spd. I have been given conflicting advice (from reputable shops) about what will work. I've been told:
1. Any 10 spd chainset (campag, shimano) will work ok
2. Shimano will but campag won't
3. 10spd chainset won't work with 8 spd (because of the chain/chainset incompatibility)

I don't want either to upgrade to 9/10 spd because of expense or to fit a new triple chainset. My first choice would be the Campag Centaur Compact if it will work ok. Can anyone help please?

Simont
[/list]

[PW]

Phone Spa Cycles in Harrogate. (01423) 887003. or look on their website www.spacycles.co.uk They'll give you good advice & there's almost certainly a Stronglight chainset to fit. The Impact model will probably fit the bill.
(Usual disclaimer, I'm just a long standing customer).

[Steve]

I have similarly combined a 10speed compact chainset with 8 speed cassette & chain and although it works I have encountered problems. The chainrings are fatter than on an 8 speed chainset so the chain rubs on the big ring, when running on the small ring and the outer sprockets, a combination which I need to use because the 34/50 rings mean there is little overlap in gearing. I think a bit of tinkering with a longer bottom bracket & packing out the chainring bolts ever so slightly will alleviate this though, when I get round to it. The indexing at the rear works fine though & there are no problems with front shifting (using a Sora mech for 8 speed chain) - I think 9 or 10 speed front mechs might be too narrow so went for a wider one. But now I think Sora is going to 9 in 2008.

[leftpoole]

I am attempting to upgrade/liven up my 20 year old Dawes Super Galaxy. I've got Shimano 8 spd bar end shifters (front non indexed), HG70 11-28 cassette, sram chain and ultegra (double)front and (long) rear mechs. I want to fit a compact chainset but all those of similar quality to the other components (Centaur, Ultegra, 105) are 10spd. I have been given conflicting advice (from reputable shops) about what will work. I've been told:
1. Any 10 spd chainset (campag, shimano) will work ok
2. Shimano will but campag won't
3. 10spd chainset won't work with 8 spd (because of the chain/chainset incompatibility)

I don't want either to upgrade to 9/10 spd because of expense or to fit a new triple chainset. My first choice would be the Campag Centaur Compact if it will work ok. Can anyone help please?

Simont
[/list]

Hello,
ANY chainset will work with your setup. Just go for what YOU want but if going for a compact (which to my thinking is daft as you should go for a triple) make sure that you have the correct (suitable) front gear mech.
John.

[ddddddd]

make sure that you have the correct (suitable) front gear mech.

Ah, no, because ...

I've got Shimano 8 spd bar end shifters (front non indexed)

I expect you would have no problems using the existing (ultegra double) front mech. (So long as it currently works okay.)

Looking back in time, people used doubles with small inner rings, successfully. I mean, way before anyone thought of selling them another front mech specially made to go with it.

As far as I can tell, it's only with front indexing and/or triples that it can become critical to match up the front mech to the rest of the set up. (And hence the chainline also.)
[Caveat for anyone moving towards much smaller rings - What you will need is enough room in the front derailleur cage for the chain to drop a little lower. Read the article ... ]

[url=http://www.ctc.org.uk/DesktopDefault.aspx?TabID=%204068]Here's the relevant CTC Technical Section:
Home/Bikes & Bits/Bicycle Bits/Derailleur Gears/Front Shifting[/url]*
Wade through and become an expert, or just skip to the bits titled:

• Front mech
• Inner chainring size
• Compact road
• Adjustment

*Note to editor: What about Campag QS, do you have any info?

[simont]

Thanks for the advice. I know (john28july) that a triple is more versatile but I've hardly used the small chainring for years (because of the type of cycling I do rather than my fitness) and compacts do look nice!