Power2Max Rotor 3D installation query

Crashs2k

Just got my Power2Max Type S (powermeter only) last night and installed it on my bike which has been running Rotor 3D crank and Q Rings.

Pretty straightforward apart from the crank installation. The manufacturer's recommended torque for attaching the crank to the spider is 40 - 50nm. Given that the lockring is installed using a specific 32mm hex tool on the inboard side which threads over the crank axle, I can't for the life of me work out how to use a torque wrench to tighten the lockring to the recommended settings without investing in a crowfoot spanner!? Anyone have any ideas?

I have emailed Power2Max support and the only response I have received so far has been confirming the torque values and that it is important. I am continuing to follow-up with them.

Anyone have any experience installing a Power2Max to Rotor cranks care to comment?

I'm not worried about it becoming loose as I tightened it as much as I could (using an adjustable wrench) and loctite. I just have a niggling doubt as to whether the accuracy of the power readings will be affected if the crank isn't attached to the P2M within the 40 - 50nm torque range.

TIA.

Crashs2k

Just heard back from Nicholas and apparently readings aren't affected - as you were...

xavierdisley

It's not important, don't worry. I've tested the spider and chainring bolt torques with a P2M and it's pretty insensitive to torque settings (even if you lose a chainring bolt!). Just ram it up fairly tight and it'll be fine. If you're using Q Rings and want to swap them on and off between round and Q Rings (don't train on the Q Rings all the time) then best idea is to put a load of grease around the locknut as well.

Xav

Crashs2k

Thanks Xav. Are you suggesting not to train on Q Rings all the time? If so why?

xavierdisley

Yes, don't do it. They mess up your pedal stroke if you train on them all the time, and are designed around making best use of a pedal stroke that has been honed on round rings. The more you ride them, the less benefit you'll get - so reserve them for racing, hard rides or familiarisation rides only

Xav

ollie51

xavierdisley wrote:

Yes, don't do it. They mess up your pedal stroke if you train on them all the time, and are designed around making best use of a pedal stroke that has been honed on round rings. The more you ride them, the less benefit you'll get - so reserve them for racing, hard rides or familiarisation rides only

Xav

Aye, they're designed to use the natural quad dominance that many cyclists have and use it positively to generate more power. Although many studies say that it makes an inconsequential change to power output, and use will only promote further quad dominance. Basically the real solution is to reduce the quad dominance of your pedal stroke by working on activating your glutes, not chuck Q rings on. Kind of like having a sports massage to deal with a tight ITB instead of attacking it with a foam roller day in day out. Pretty much every bike fitter or physio I ever spoken thinks they're terrible things, only good things I've heard about them are from salesmen...

xavierdisley

The science is sound, testing them is difficult for a number of reasons though. Of course people have natural "quad dominance", the human body is designed for knee and hip extension and you definitely want to make use of that rather than reduce it!

Xav

devildawg

P2M are another example of internet direct sales cowboys who will not honour their warranty obligations when their badly made devices fail. I found out the hard way and will now stick to known brands like Quarq/SRAM.