A new rear wheel, which would also need to be standard quick release for your frame (no thru-axle). You really just need a hub that can accommodate a 12 speed cassette, but buying or building a new rear wheel will likely be an easier path than disassembling your current wheel and lacing a new hub to the old rim. Depending if you go SRAM or Shimano on the new drivetrain, there are specific freehub requirements to run a 12-speed cassette. For SRAM, you need an XD driver to run their Eagle groupset, and with Shimano you need their Microspline freehub.

If you do replace the front wheel so that they match, the front hub width is 100mm. I also noticed you originally suggested 2×12. As far as I know, the current 12 speed mountain setups are all made for 1x, and the 12 speed derailleurs likely cannot handle the amount of chain slack you would get with a 2x. The move toward larger cassettes is mostly to avoid the need for multiple chainrings, thereby simplifying shifting, reducing chain drop, reducing weight, etc. The current 1×12 setups can provide a 500% gear range which should be plenty!

Would that be a new rear or front wheel? and if I need to replace both, do both need to be 135mm?

Hi Jonathan. You can certainly put a new crankset on your Paratrooper, either single or double chainring, as long as it uses a 68mm english threaded bottom bracket. Installing a 12 speed cassette would require a new wheel, but it could be done. The new hub just needs an overlocknut dimension (hub width) of 135mm.

Is it possible to swap out the entire groupset to 2×12? as much as I’ll lament the loss of my 3rd gear, alot of high-tier industry parts are going towards 2x groupsets, and I really want to soup up my paratrooper. Also, the new Shimano XTR is looking pretty appetizing. I’m aware that it woukd take alot of part-swapping and probably a couple visits to a good bike shop, but if it’s possible I’d like to know, because I’d like to try.

The crank arm length is 175 and uses 38 and 24 tooth chainrings. The bottom bracket shell is 68mm english threaded and uses 113mm spindle length. The stock setup is an Octalink splined spindle (Shimano BB-ES300), but if you’re changing the crank as well then you could use a different interface.

I own a 2016 Highline, very pleased with it!

Thinking about replacing the crankset, what size is the crank arm and bottom bracket? My guess is 175mm with an 83mm BB – how close am I?

Thanks!

Hey Cullen. You can certainly get just a chainring without replacing the whole crankset. A five bolt ring with a Bolt Circle Diameter of 130mm should be perfect.

I can see from the web site it’s a 42t and I can see from photos and my bike it as 5 bolts, but what are the exact dimensions? And can I just replace the gear without having to replace the whole crankset?

Thanks in advance,

Cullen