Rotor aero chainring and Power2Max

Help please
Purchased a P2M power meter and my LBS says that the power meter can’t be fitted to a rotor aero chainring
Any suggestions?
Just a matter of buying a non aero Rotor outer chainring?
Jonboy

Check the P2M website. From what I recall, an aero chain ring could not fit on a 110BCD crankset, but could work on a 130BCD.

I just did this with my P5. Dremel a small chunk of the aero chainring out. Took me about 20 minutes going slow and continuously checking the fit. Turned out great. I think it was a 110.

I ordered the Aero Q rings 110 BCD with my P2M. Michael was kind enough to dremel it for me and fit the spider to the crank. Works perfectly.

Here’s the mod I made:

http://i43.tinypic.com/qq3d41.jpg

and

http://i44.tinypic.com/2qte528.jpg

Dave
.

I run Rotor 54/42 aero Q rings on my P2M (130mm BCD) with no problems. Derailleur required minor adjustments, that was all. But, as others said, 110mm BCD is a little different - may require trimming down the back of your battery compartment.

Hi there,

Nicolas from power2max here.

It’s right, 130BCD aero rings don’t pose any problems, 110BCD can be dremeled, which we don’t recommend, but it’s possible.

Please, under no circumstances, trim the battery compartment! It will damage the battery compartment, compromise the water proofing, and void warranty.

Wishing you a great summer,

Best
Nicolas

Hi Nicolas,

quoting from my Power2Max product manual:

aCAUTION! If you want to mount power2max powermeter with a 130 mm BCD aero chainring,
you must shorten the chain catcher at the battery cover by 1 to 2 mm to avoid its collision with
the chainring. Then, the distance between chainring and chain catcher in mounting position
should be about 1 mm. For shortening by grinding, we recommend the use of abrasive paper.

Maybe it’s been updated since then?

Hi Wickert,

the chain catcher is the little metal bolt that sticks out of the chain ring. That you can sand down if needed. However, please don’t trim the battery compartment itself. Thanks for the heads up, I will reread our product manual carefully.

Best
Nicolas

The manual I have definitely says you can trim the chain catcher on the battery compartment:

“If you want to mount power2max powermeter with a 130 mm BCD aero chainring, you must shorten the chain catcher at the battery cover by 1 to 2 mm to avoid its collision with the chainring.”

You wouldn’t achieve anything by trimming the chain catcher (metal bolt) on the chain ring - it’s on the opposite side of the problem area.

Uuups, embarassing, I got things wrong in my head. Yes, there is a little “nose” on the back of the battery compartment that can be trimmed very gently. Please don’t trim the the battery compartment in another way though.

Best
Nicolas

The manual I have definitely says you can trim the chain catcher on the battery compartment:

“If you want to mount power2max powermeter with a 130 mm BCD aero chainring, you must shorten the chain catcher at the battery cover by 1 to 2 mm to avoid its collision with the chainring.”

You wouldn’t achieve anything by trimming the chain catcher (metal bolt) on the chain ring - it’s on the opposite side of the problem area.

yes it says that and I was prepared to do it but found I didn’t have too. 54 Q-ring aero fit just fine. Now I have a 55 tooth SRAM aero and it fit just fine also.

Hi djmercer
Looks good, no problems with chainring when you modified it?
Did you have to do anything to the power meter itself.
Jonboy

Zero issues. I thought I had slightly caused a bit of runout doing my mod, but I was mistaken. It’s dead flat. I’m going to do my Q-Rings probably tonight now that I’m happy with Position 4 on the MAS system mated to my P5.

The PM just bolted on. No mods done to the P2M at all.

FYI, I used a standard non-aero chain ring to model the inner section of the cutout, and the Mark I eyeball for the outer section, rounding all corners, deburring as appropriate to avoid the possibility of stress fractures. There is ~1 mm clearance all around. I used a Dremel to do the rough cuts, then for the finer detail work, varying width flat hand files and rat tailed files, plus a fair bit of patience. In all, I think I spent 3 hours from start to finish. I do encourage anyone to NOT apply a lot of force or rush the process by cutting with a lot of pressure, as heat and pressure will risk warping the chain ring. Take your time and all will be fine.

Dave

Hi Dave
Thanks for info
About to tackle chainring
Was wondering if you have any photos of the reverse side of chainring both with power meter installed and just chainring.?
Cheers
Jono

Hi there,

Nicolas from power2max here.

It’s right, 130BCD aero rings don’t pose any problems, 110BCD can be dremeled, which we don’t recommend, but it’s possible.

Please, under no circumstances, trim the battery compartment! It will damage the battery compartment, compromise the water proofing, and void warranty.

Wishing you a great summer,

Best
Nicolas

Has anyone tried mounting a Vision Aero Chainring 52T/110mm BCD on power2max? It seems to have a bit more room so I was curious if it would fit without cutting. I know it is not a rotor, but I was impressed with the shifting of my Vision TriMax Carbon Cranks with the aero TT rings prior to swapping in a Quarq, and the rings are reasonably priced.

http://www.bikewagon.com/vision-aero-chainring-52t-110mm