Hi all,
I'm considering converting a 135mm dropout CX frame to an ebike using the G310 motor. The current drivetrain is a 10 speed shimano road cassette in the back.
I'm not sure what to make of this blurb from the Grin info page for the motor: https://www.ebikes.ca/product-info/geared.html#bicycle-fitment
If you look at the bottom half of this diagram:
https://bikerumor-wpengine.netdna-ssl.com/wp-content/uploads/2012/05/DT-Swiss-Shimano-11-speed-hub-diagram2.gif
you can see that the 10 speed shimano road cassette has a 35mm freehub body which hasn't changed in decades; in fact that same freehub body is also used for 7 (with spacer), 8, 9, 10, and 11 speed Shimano MTB cassettes.
The G310 has the exact same 35mm freehub body, specifically marked as a Shimano 7-10:
https://www.ebikes.ca/documents/MG310.pdf
You can see here that 8/9/10 speed MTB all have the same width of cassette (11 speed mtb is the same, road is not):
https://www.bikeman.com/bicycle-repair-tech-info/bikeman-tech-info/1640-how-many-gears-can-i-put-on-this-thing
So my questions then:
I'm considering converting a 135mm dropout CX frame to an ebike using the G310 motor. The current drivetrain is a 10 speed shimano road cassette in the back.
I'm not sure what to make of this blurb from the Grin info page for the motor: https://www.ebikes.ca/product-info/geared.html#bicycle-fitment
Cassette Stack Height: With a 9 or 10 speed freehub, an additional 12mm washer is sometimes needed on the right side to accommodate the larger gear stack and have the chain clear the dropout. This will increase the OLD to 139mm.
If you look at the bottom half of this diagram:
https://bikerumor-wpengine.netdna-ssl.com/wp-content/uploads/2012/05/DT-Swiss-Shimano-11-speed-hub-diagram2.gif
you can see that the 10 speed shimano road cassette has a 35mm freehub body which hasn't changed in decades; in fact that same freehub body is also used for 7 (with spacer), 8, 9, 10, and 11 speed Shimano MTB cassettes.
The G310 has the exact same 35mm freehub body, specifically marked as a Shimano 7-10:
https://www.ebikes.ca/documents/MG310.pdf
You can see here that 8/9/10 speed MTB all have the same width of cassette (11 speed mtb is the same, road is not):
https://www.bikeman.com/bicycle-repair-tech-info/bikeman-tech-info/1640-how-many-gears-can-i-put-on-this-thing
So my questions then:
- Why would I ever need a spacer? The furthest-right cog (smallest) is always the same size at 11T and always in the same place regardless of the cassette.
- Why a 12mm spacer? That's huge!!! (did they mean 1.2mm?)
- Can I expect my existing 10x road cassette to work without spacer?
- If I ever do a flatbar conversion and move to a MTB 1x11 drivetrain, can I expect an 11spd MTB cassette to work without spacer?
- Thoughts on stretching aluminum 135mm dropouts to 138mm?