Apologies in advance if this question has an obvious answer:

I bought a 2nd hand bike which has an XTR race chainset, being weak and feeble I am struggling with the gearing on really steep climbs, so want the change the chainrings to make the range of gearing a bit more similar to what I am used to (happy with the 2×10 idea though, which is new to me to)

At the moment it has 42 and 30 chainrings, a trail XTR double has 38 and 26, but has different BCD. I can’t seem to easily find 26 chainring with a BCD of 88 which is what current chainset is.

If I could find one, could I just change the small chainring or would this make the difference between the small and the large chainring a bit strange? And is it just the 26, BCD 88 and the number of bolts that defines the ring I want or do they come in different widths, etc?

Or I could just shift down to at 28 ring instead which is quite easy to get hold of?

Or am I better off just selling the whole chainset and buying a new one (it is in good condition (2011) so could probably get reasonablish money for it?)

Sorry if these are dumb questions, have spent the last 4 years spending no money on bikes and doing not enough riding due to having kids and am feeling a bit confused 😕 (Even 2×10 is a new concept to me)

Thanks!

There is as you say a 28 that fits but to go to 26 you need a whole new crank. Mental eh.

Bah. Indeed mental. And expensive!

M985 chainrings are specific to that chainset, and are indeed the 88 BCD which can’t be found anywhere.

You certainly can’t stick M980 on there, as it’s 104bcd (I think).

Frankly mental, and the only place that you can get aftermarket rings is that american dude who take 3 years to make them…

May just have to change for a 28 and toughen up!! Thanks.

Can you swap the cassette out for something with a bigger top cog or are you maxed out there already? What size cassette do you have now?

11-36 I think.