Hi,

I considering to upgrade my hybrid 2014 Boardman MX Sport to 1x. I would love the simplicity of 1x, as I switch to 1 or 3rd cog on my front derailleur only in very rare circumstances. Plus Id like to have clutch derailleur too.

I have to replace crankset too, because I want it shorter than 175 (170 or even 165).

However I found that MTB 1x cranksets are mostly go around 34T and even if 38T is listed on manufacturer site it is very hard to source, from the other hand the road/cx crankset are easy to get and 42T would be just perfect for me.

The problem that I am not sure if that will work, and if so would I need long rear derailleur to make it work with 11-42T rear and 42T front, or medium would be fine and how to calculate that? All formulas I could find are supposed you have 2/3 x front cogs, and simply do not work 1x…

I plan to use SRAM NX/GX and probably Force for crankset.

I have a 42t alfine front, 11-36 xt cassette, SLX med cage 10spd mech. Medium cage will be fine as it’s just the difference between top and bottom of the cassette for 1x drivetrain.

For 1x setups, the size of the front chainring doesn’t matter, as it doesn’t change – so calculating capacity is just (biggest cog on the cassette) – (smallest cog on the cassette)

Is the spindle the same length on road and MTB chain sets?

As I recall, it isn’t, which would be an issue.

Thanks a lot!

Is the spindle the same length on road and MTB chain sets?

I think I will need to replace BB as well and may be use some spacers, I hope that will be enough.

igm – Member
Is the spindle the same length on road and MTB chain sets?

As I recall, it isn’t, which would be an issue.

Not a big one for an external BB. Road designed for 68mm BB, MCTB ususally 68/73 compatible – just a question of using spacers for an MTB crank or not for a Road one.

The Boardman MX Sport 2014 have

Your bike takes a square taper bottom bracket, where as the groupset that you wish to fit requires a PF30/gxp style bracket. Your frame can fit one, so doing this swap is possible.

That was commented regards SRAM NX Crankset.

So I think everything should be fine.