Wileyrat

I'm looking at a couple of Bikes Direct hardtails and my decision has come down to a Sram NX 11sp vs NX Eagle 12sp for a hundred bucks more. I do a lot of flatish desert riding, and just don't bother with a lot of climbing.....I leave that for my roadie.

I'm a kind of Sram fan (Force 22 on the roadie), so it's between those two.

What say you?

Kapusta

If the 11 speed has the range and spacing you like, not sure I see the need for the 12. I do ride in mountains. I recently went 11 speed on two bikes. 28 x 11-42 on a fat bike and 32 x 11-46 on the full suspension AM bike. Both have all I need.

But only you can know if the added range or tighter gear spacing is worth it. What are the specific gearings on these (ring and cassette size)?

Wileyrat

11x42 and 11x50 cassette with a 32 chainring, the cassettes are the same spacing until the 50. Right now I'm on a 11x36 10sp Deore with a triple, and I never go off my middle ring, which is 34.

I think "today" I'm leaning towards the 12sp, but we'll see.

Kapusta

You may have already figured this out, but the 11 speed looks like it gives you a range just a little bigger on each end compared to your current middle ring.

Something else to consider is whether the 11 sp NX derailleur can clear a bigger range cassette (like 11-46) in case you decide you do want more range. If not, the 12 may make more sense just for the flexibility.

Wileyrat

I thought about the 11x46 idea, but didn't find anything in a short search. My thinking now is if I never use the 50, oh well, but if I need the fifty and was too cheap to go for it, I will not be happy.

HerrKaLeun

If you ride in deep snow or sand etc. you want low gearing because you go quite slow against high resistance.
My fatbike came with a 30T chainring and 11-42 cassette. I switched to a 26T oval chainring. then to a 11-46 cassette. Perfect range for me. On asphalt i barely use the 11T cog and alos use the 46T cog quite a bit without needing even lower gearing. If i had a 50t cog, i probably would use it, though.

I'm not really strong or fast, but this gives you an idea that a fatbike needs some low gearing depending on conditions. When i bought mine 2 years ago they didn't come with a 12 speed option. Today, i'd go with the 12 speed. For the extra $100 you don't need to upgrade drivetrain parts. YMMV.

Bicycle Gear Calculator

Darth Lefty 

I like my 11-42. I think I’d like a 10-42 or 11-46 better but not enough to buy one before it wears out. I think 11-50 would be nice too. Don’t get hung up on this.