I am trying to replace the non drive side arm of my XTR crank. It looks pretty straightforward and the manual says all you need to do is us an 8mm allen and loosen the bolt. Mine seems to be really tight and when i put a cheater bar on it I am getting some popping noises but the bolt doesn’t turn.
Am i missing something? I dont really want to break something if there is a trick i am missing.
Any chance you can snap a pic so we are sure which exact model you have?
OK, I have not handled that Shimano style, but have plenty of experience with the SRAM version that is similar. For SRAM at least, it can take a HUGE effort to “break” the bolt and crank loose. I end up placing a pedal on a step or firm support, and then actually push down on a long 8mm wrench with my foot to get enough force.
I won’t say that is right or necessary for the Shimano, but this type of crank removal problem is seen elsewhere.
Thanks. I have had similar experience with others.
The part I find a bit unnerving is the popping sound when I put a cheater bar on it. It sounds feels like the Allen key is turning inside the bolt. I don’t want to round out the bolt.
Yeah, I get the concern about stripping the screw head and/or threads.
Popping noises are not uncommon when doing this type of removal, but can be a precursor to failure. Hard to know which it is until something “gives”… 
Well someone’s mangled that Stages arm getting it off, so I’d imagine it’ll take a fair bit of force (and use a decent allen key/bit)
Great point. From the looks of your “new” power meter arm, it’s been removed with similar effort and force you are experiencing with what I am guessing is a non-power meter version on your bike. To be honest, I’d consider replacing that crank screw on your new one before installing it. And even when that’s done, take the proper steps to grease the crank, screw head, threads and such to make future removal as easy as possible.
I noticed that as well. The existing Powermeter threw craps so they sent me this as a replacement.
This is a dual sided Powermeter and have not been impressed with its reliability.
You mean XTR 9100 single bolt crank removal. Is it on a M9100 crank? Is it a reverse thread( Lefty tighty, righty loosy)
https://www.reddit.com/r/MTB/comments/nton1k/remove_xtr_m9120_crank/ this indicates the friction is actually pushing the arm off the splines rather than just loosening the bolt. There should be friction. Try hitting the arm sideways at the pedal a few times. Maybe using some bolt loosening compound on the splines. Shimano says this is a 45nm install, so thats about a 90nm (70ft/lb) release - that would be standing on a normal allen key.
Try penetrating oil (wd40 if you have it on hand or Penetrating oil test | The Garage Journal ) a long wrench, and a smooth push.
Reinstall with some grease or anti-seize. I suggest a proper long 3/8 tq wrench and a 8mm socket
I believe it’s a standard thread. The Shimano manual didn’t state otherwise but also didn’t provide a lot of detail.
To bring this to some closure took the bike to the LBS and it’s swapped.
Need to talk to them about what they did or found.
I routinely take mine off once or twice a year as part of my mid and post race season maintenance ritual.
I’ve tried a few different techniques but found that the most reliable is to make this a 2 person process.
I will remove the chain and then while I hold a socket wrench on the non drive crank arm, my son will step/stand on the drive side crank arm to loosen the bolt. Works like a charm every time.
