A friend has a pair of SRAM s1000 gxp cranks fitted on his bike. It’s a double ring setup using 42t and 28t rings. He wants to convert 1×10 but the outer ring is 120bcd and the inner is 80bcd.
He wants to fit a 32t narrow wide ring on but he can’t find one in the larger 120bcd size. He has found one that comes in the 80bcd size but that would mean mounting it to the inner ring tabs on the crank when he would prefer it to go on the outer ring tabs.
Using the inner ring mounts also means the cranks look a bit ugly with the outer tabs exposed so he’d need to cover them up with a bash ring.
Does anyone have any suggestions as to where he can get a suitable 32t ring in a 120bcd size?
He’s looked online and doing this would cost around £100 for the parts.
His other option is to change the cranks for some with a more normal bcd measurement. With the bottom bracket being a gxp unit what are his options with regards to replacing the cranks?
The bike in question is a 2015 Boardman pro
Muchos gracias!

gonzy – Member

With the bottom bracket being a gxp unit what are his options with regards to replacing the cranks?

GXP would restrict him to SRAM. But tbh it’d make more sense to replace both at the same time since sram bbs are pish.

So what bottom bracket would he need? I’m assuming it’s a pf30 that’s in there at the moment.

You won’t get 32 in a 120 pcd. Wolf do a 36t in 120, better than trying to use the inner ring the chain line will be horrible at the top of the block. Has he measured the actual crank pcd or checked the markings? I thought most of the OEM sram s1000 cranks were 104, worth checking in case.

For £100 if you hunt about you’ll probably find a suitable sram crank – you could put a shimano crank and narrow wide on there for less but if it’s a pf30 BB supply and fit a new one to suit will probably cost north of £50 on its own.

Wiggle have the correct gx1000 crank in gxp with 32t narrow wide chain ring for £85 if any good? Cheapest is tweeks at £71 but 10 days delivery.. http://www.wiggle.co.uk/sram-gx-1000-1x-gxp-chainset-with-32t-chainring/?lang=en&curr=GBP&dest=1&sku=5360710902&ci_src=18615224&ci_sku=5360710902uk&utm_source=google&utm_term&utm_campaign=UK_PLA_Components&utm_medium=base&utm_content=sJXeGKCsr_dt%7Cpcrid%7C67090789502%7Cpkw%7C%7Cpmt%7C%7Cprd%7C5360710902uk

I’ve got some SRAM S1000 crankarms, brand new, GXP fitment, but crucially they’ve got the normal 104BCD spider… They came on my new Hardtail, but I changed them for my old Raceface Turbine’s immediately.

The other option would be to ditch SRAM, and fit a Shimano HT2 crank setup and a 32T middle ring, but this will work out slightly more expensive in the short term as I don’t need much for these cranks anyway.

Happy to sell just the arms without rings, or can do with a 32T narrow/wide too if required. My email is in my profile…

Has he measured the actual crank pcd or checked the markings? I thought most of the OEM sram s1000 cranks were 104, worth checking in case.

yes he measured them and the outer was 120 and the inner was 80. the markings on the chainrings confirmed this.

I’ve got some SRAM S1000 crankarms, brand new, GXP fitment, but crucially they’ve got the normal 104BCD spider… They came on my new Hardtail, but I changed them for my old Raceface Turbine’s immediately.

The other option would be to ditch SRAM, and fit a Shimano HT2 crank setup and a 32T middle ring, but this will work out slightly more expensive in the short term as I don’t need much for these cranks anyway.

Happy to sell just the arms without rings, or can do with a 32T narrow/wide too if required. My email is in my profile..

he’s got the chainring already so the crank arms would be perfect. i’ll send you an email.