Installing PAS Sensor/magnets on hollowtech crank

[buchhla]

Hi all, I am in the process of trying to install a Q128C based system from BMS Battery on my road bike. I have been going back and forth with BMS Battery and have kind of hit a wall. My bike uses 2006 era Shimano 105 Hollowtech cranks and matching bottom bracket. I enlarged the center hold on the magnet disk so it would fit on the 25mm shaft, but I don't have the clearance between the crank and the bottom bracket itself for the magnet disc.

ie, when I install the crank, the disc is deformed from the crank pressing on the disk the the pedals don't want to turn. I see a few other companies sell discs that attach to the small chain ring on the other side, which looks like it might work, but I don't see a source for these in the US, just china or the UK/DE so I want to know this will actually work before I spend time and money trying it.

I didn't take a photo with the disc installed, but I have some of the general area showing the lack of clearance. Am I missing something, or do I need a different setup?

 

[Marin]

Grin has pas rings for the crank side. Mine is a two piece that uses the magnets to fasten it.

 

[buchhla]

Do you have a link? I see two split ring sensors on ebikes.ca, but the one for the crank side specifies it is only for square taper bottom brackets. The one for the chain ring side might work though... I see the same products at Dillenger, but that is about it.

Thanks!

 

[Marin]

This is what I'm using on the small chain ring, PAS_12P_Chr from grin, without the mount, just the 2 piece magnet ring affixed by the magnets,

seems to work well,

 

[buchhla]

Awesome, thanks!

 

[irq]

Had the same Problem, gone the Ghetto Way of solving this. Removed all Plastic Holders on the PAS Disc, mixed some of my loved Epoxy and glued it onto the small Chainring (2 Chainrings in my case). Fits perfect, and i bet the Epoxy will last longer than the Chainring. So far, about 2000km without any sign of issues.

 

[Marin]

You can see it on the small ring. It's 2 piece so just clean ring and install.