Boost 11 speed cranks

rockmonkeysc

Having just come back to mountain biking after 5 years away I'm building up a new frame ad I'm baffled by cranks, it used to be simple.
My frame is a large Transition Patrol 2018 with boost rear axle and 73mm bottom bracket. I've got a shimano XTR bottom bracket and running 11 speed, all parts from my old frame.
I cannot find a boost compatible 11 speed crankset and it seems boost cranks aren't compatible with my old 11 speed chainring.
I phoned Tredz and they told me 12 speed chain rings won't work with 11 speed chains.
Am I going to have to change everything to 12 speed? I'd rather not if I can avoid it.
Why are bicycles so complicated?

rockmonkeysc

I used to regularly visit this forum several years ago. Back then I could guarantee an answer to a question like this with in half an hour. After 8 hours there would be at least 10 replies, half of them telling me I'm an idiot 3 telling me I should be riding a rigid single speed, 5 telling me I need a whole new bike and 2 telling me exactly what I need to know.
It's really died. What happened? Did the crappy new format kill it off?

whyamihere

rockmonkeysc said:

Did the crappy new format kill it off?

Yep, pretty much.

It very much depends which cranks you want to run. Shimano did Boost spacing at the crankset/spider, so any chainring mounted to a Boost Shimano crank gets that spacing. For the direct mount cranks used by Sram, Raceface etc, the amount of dish on the chainring itself changed, so you could fit Boost or non-Boost chainrings to the cranks.

Tredz are also talking nonsense, as long as you're running 1x, a 12 speed narrow wide chainring is fine with an 11 speed drivetrain.

Of course, all this would be avoided if you rode a rigid singlespeed like a real mountain biker...

rockmonkeysc

Thanks. If 12 speed rings work then it's easy.

vincesummerskRoxcBTr

Handy post , I have now heard of Boost axles !

JBA

Tredz are talking rubbish.
I have been running a 12 speed chainring on my 11-speed hard tail for the last 18 months with no problems at all.

The Rookie

As above, 12 speed rings work on 11 just fine. Just a 'safe' answer from Tredz from someone who probably has little or no technical knowledge.