MTB Double Chainsets with high tooth counts?

[User84300]

I need to buy a new Shimano compatible chainset for a bikepacking/mountain bike, either a double, or maybe a triple set that I can convert into a double. My problem is, I want a main large ring of 40t or 42t, and a small ring of 30t or 32t. A 38/28 is not enough for the ratios I need

I am surprised to find myself having real problems finding such rings, or even a 30t or 32t ring with BCD of 64mm to fit to an old SLX crankset.

Any chainset suggestions folks?

I nearly bought the new M6000 Deore double set, but learnt that the ring bolt pattern is unique and not symmetrical, meaning nothing larger than 38/28 is possible

 

[fossyant]

You won't find an MTB chainset. A 38 vs a 40 is minimal - you just won't quite go as quick. Pedal faster.

 

[fossyant]

I run 2 x 10 on my full suspension - not keen on 11/12 gears as it's used on the flat and hills, so I need tighter gaps. Mine is 38/28, and yes I run out at the fast end...

 

[mickle]

Can you find an old 110 chainset on ebay and buy new rings for it?

 

[TheDoctor]

Something like this one?
https://www.decathlon.co.uk/7-to-9-speed-triple-chainset-175mm-42x32x22-id_8003052.html

 

[cyberknight]

would a sub compact chainset or something off a hybrid work?
my subway has a double with a 48 outer .

 

[biggs682]

@User84300 have a look at the own brand one from Sjs Cycles and or Spa sure they offer just what you want

 

[User84300]

Success!! Or, partly at least
Thank you folks for your messages. I have bought a Shimano Deore M617 double chainset at a bargain price
It now has the correct main outer 40t ring fitted to it (104BCD).
All I need to do now, is find a 64BCD inner ring (4 arm) with either 30t or 32t, and I will have perfect gear ratios at my fingertips I am assuming that for a inner ring, I can use any brand I like.

Any suggestions?

The only one I can find, is a "9 speed" but a good quality ring. Would that work ok with my KMC X10 chain and 10 speed train?

 

[fossyant]

9 speed will work

 

[User84300]

9 speed will work

Thanks Fossyant
I've now successfully calculated and sorted out my perfect gears I've managed to find and fit, a good quality 30t ring to my crankset, and although it's technically 9 speed, it is running and shifting up and down as sweet as a nut I have also fitted a new 10 speed cassette (11t-28t), but will keep my newish 11-34 one as a spare.
The result is finally, perfect gear rations, with plenty of 4.5+ ratios to give plenty of road speed when needed, without needing to run to the end of my cassette and crossing my chainline awkwardly. Perfekkt! Now I'm ready for all round bikepacking touring action while still having three hillclimbing ratios for those gradients. My philosophy is, for touring, if a hill is too steep for a tough hillclimb, save energy and don't struggle...just walk

 

[I like Skol]

Similar situation here. Was just browsing the net for a new chainset for my MTB as I fitted a pretty basic chainset last time I rebuilt it and the middle ring is getting worn.
I currently run an M442 triple as a double (the two big ones, dropped the granny ring as I don't use it) with 32/44T rings and the ridiculously small current chainsets just won't do. I did want to 'upgrade' to something XT to match the rest of the bike but in the end just bought a couple of genuine 32T chainrings for my existing set-up, just under £9 each

 

[User84300]

Similar situation here. Was just browsing the net for a new chainset for my MTB as I fitted a pretty basic chainset last time I rebuilt it and the middle ring is getting worn.
I currently run an M442 triple as a double (the two big ones, dropped the granny ring as I don't use it) with 32/44T rings and the ridiculously small current chainsets just won't do. I did want to 'upgrade' to something XT to match the rest of the bike but in the end just bought a couple of genuine 32T chainrings for my existing set-up, just under £9 each

Well done for finding those 32t chainrings, they are becoming rare.