I was going to buy the new XT 28t/40t cranks for racing on next year and converting my Anthem to a 2×10 rather than the tired 3×9 I have on it now.

But I was wondering is there anything to stop me sticking a 28t granny on my SLX and a 40t middle ring?

Currently I have a 26t and 36t and haven’t noticed either being tight on chainstay clearances or anything so I assume there is no big deal about making the change?

Who sells nice big chainrings then???

Nothing stopping you doing that at all, assuming you have the clearance.

You’ll need narrow chainring bolts and you may find that a double specific front mech is more reliable at stopping chaindrop though.

If you stick with 9 speed just use your current front mech, if you go 2×10 then a 10 speed XT double one may be marginally better, I personally never had problems with that combination and a normal triple front mech.

TA Chinook chainrings get my vote, Starbike.com are generally much better value than the UK sellers, and have better stock.

I was just about to post about narrow chainring bolts but was beaten to it!

As for chainrings, check out Middleburn.

If you stick with 9 speed just use your current front mech

Not my experience unfortunately – I found that no matter how I set up my front mech (using 24/36 and an XTR 9speed triple front mech), the chain would come off 5-10 times per ride. An SLX double front mech stopped the problem immediately.

velosolo for chainring bolts,
i can personally vouch for middleburn rings, they last ages and are reasonably priced.

I already have narrow bolts, used to run these as a double on the trail bike.

Cheers for the chainring advice, can only see 4 bolt middleburns up to 26t on the granny, will check out those other options.

Not my experience unfortunately – I found that no matter how I set up my front mech (using 24/36 and an XTR 9speed triple front mech), the chain would come off 5-10 times per ride. An SLX double front mech stopped the problem immediately.

That’s because the SLX double front mech has a ‘tighter’ curve to suit smaller rings – which you were using. If you’re using larger rings the curve on the SLX mech is too small, you’re better off with a normal triple front mech.

I ran a normal triple one for 3 years, never once dropped the chain.

I run 28/40 Specialites TA rings on my M970 XTR canks, no problems. I also use an M950 (triple) XTR front mech with no issues.

If you’re using larger rings the curve on the SLX mech is too small, you’re better off with a normal triple front mech.

I think this is correct – pretty sure I read the SLX double is only designed to go up to 36 teeth as the largest.

Middleburn ring compatible with 10 speed? or is that a whole different flame war?