Confusion with new chainrings

[chris667]

Hello

I have been out of the loop a very long time with cycling bits. There is one good bike shop near me, but I tend to buy lots of things I need in one go when they go out of fashion.

I am on my last chainset though (I should have bought more of the 7 speedXT ones when Chain reaction were selling them for £5 each!), and I'm thinking about its replacement.

Can someone tell me - what's the deal with 10 speed chainrings and compatability with 7 speed cassettes and chains? They didn't exist when I last bought new bike parts. I see there are lots of far eastern sounding names and credible looking chainsets and I'd consider buying one next time. The price of the old ones is going a bit silly. I see Spa is doing some nice 8 speed ones, but these are about 1/3 of the price and as a consumable, it's hard to ignore that.

 

[byegad]

SPA Cycles of Harrogate are your friend, give them a call and they are very helpful as to what goes with what.
Their mail order is excellent.

 

[T4tomo]

10 speed chains are narrower and hence so are chainrings, so whilst your 7 speed chain will fit over it (note it wouldn't work the other way round) you will get play and noise and its not a good idea. Get a 7/8spd one.

 

[Cycleops]

One of my local bike shops is selling a double SqT alloy chainset for less than a fiver. Look Okay but you takes your chance on longevity and quality.

 

[Sharky]

I thought the internal width of the chains were the same. It's only the external width that is narrower for 10 speed chains?

 

[Ming the Merciless]

Why not just buy 7 speed parts. They are still available

 

[T4tomo]

I thought the internal width of the chains were the same. It's only the external width that is narrower for 10 speed chains?

you are correct (all still 3/32nds), but there is still a issue as for double (or triple) the chainrings are set marginally closer together (to compensate for the narrower outside width of chain, so shifting will still be a bit iffy / noise but fora different reason