My commuter (CX) currently runs 2 * 9 but I find myself always in the big ring at the front, and at the low to middle end of the cassette. It’s due for a new drivetrain anyway so I am considering going one by nine.

I started by looking at narow wide chainrings, but they all seem to be for four arm spiders. The current crankset is tiagra which is five arm. I also have a par of middleburn RS7s I could use, again though the spider I have for them is 5 arm. Does anyone do a five arm narrow/wide chaninring? If not then I’ll need either a four arm spider for the RS7s, a direct mount ring for the RS7s, or a new four arm crankset.

I also need to consider BB and axle width. At the moment, the chain is often going big-big so it’s quite angled. Ideally then I’d like to use a narrower axle. If I use the RS7s that’s easy enough, I can get a new square taper BB with a shorter axle. As the Hub is 135mm, any suggestions as to the axle size? I normally use a 113 on the SS MTB but the hub OLN is wider

I I stay with tiagra and the external BB, how do you adjust axle length on those? Can’t figure it out except by moving spacers from the drive side to the none drive side, but surely that just pushes the cranks over to one side?

ta

THis?

http://www.chainreactioncycles.com/ie/en/sram-force-cx1-chainset/rp-prod120578

Why do you care about narrow/wide? I’ve got 1*9 using unramped Middleburn rings on a similar type bike and the chain’s never dropped.

Actually, I am looking to strip the bike and sell the bits…

You could just go to Spa Cycles and buy an own-brand ring at the size of your choice and bolt it onto the small ring position of your current chainset. You may need some spacers or single speed chainring bolts too.

Then worry about keeping the chain on if it keeps falling off?

nettles, speak to me my friend 🙂

It’s a 44 tooth (I think) hardcoat. Plus there’s the 9spd cassette if you want it, 12-32 (again, I think). And a medium cage XT mech. And some retro-esque RF sq.taper crank arms.

It’s all attached to a Bonty Privateer frame with retro-fitted disc tabs for that n+1 goodness 😉

Warhawk make ’em: http://www.warhawkindustries.com/chainrings/5-bolt-110mm-bcd-chainring.html