Hi there all,

Newbie to the forum, although have been peeking through the curtains for a while...

I've got a bit of a conundrum that you might be able to help with; in fact it might be a non-issue.

Currently riding a Trek 1.1 kitted out with Shimano Sora stuff. Changing the 8 speed cassette to an 8 speed Sram cassette with 8 speed chain (Sram).

I didn't really want to bother changing to anything other than 8 speed as I'd then have to change the shifters. Right? (although I did get a bit carried away looking at Ultegra bits...)

It's got some standard Bontrager 5 arm crank arms and a 53/39T double chainring.

I also want to change the chainrings but am struggling to find any 8 speed in the same size (which I'm largely happy with). I can find the right T size in, what the manufacturers call 10 speed. So the question really is whether I can use a 53/39T 10 speed double chain ring (and change the chain to a narrower one?) or I have to persevere with finding an 8 speed set-up?

Sram also provide a (3mm/4mm) measurement which I assume would indicate whether I have to use a narrower chain or not? Right?

Thanks for any help.


Flying Scot [923 posts] 2 years ago

Chain rings will be available, just find out the BCD (bolt circle diameter) (probably 110 or 130mm) and Truvativ, shimano, TA or stronglight will likely do them.

Failing that, 10 speed rings will work, as your 8 speed crank will keep the rings far enough apart to law the 8 speed chain space.

Uncle Boz [1 post] 2 years ago

Thanks FS. Most helpful.