The Torque Arm V7 is a unique design that actively clamps the axle with tremendous force so that there is no play even with motors that do regen and have alternating torque. Hub motor systems with regenerative braking have been notoriously prone to nuts getting loose and axle spinout, even with a torque arm is present.
This V7 arm design works on both front forks and rear dropouts, and is compatible with motors that have M12 and M14 axles and 10mm flats to prevent rotation. It is the culmination of extensive lab testing at Grin and uses specially hardened 174 stainless steel and Grade 12 bolts right at their strength limit.
[Of course, the best solution is a motor that has the torque arm fully integrated with the axle and not as an afterthought. But if you've already got a Chinese hub motor that relies just on axle flats for torque transmission, this arm is as good as it gets.]
Here is Grin's general torque arm info page:
https://ebikes.ca/productinfo/grinp...
Here is the .pdf user manual:
https://ebikes.ca/amfile/file/downloa...
Here is where you can buy them from Grin directly:
https://ebikes.ca/shop/electricbicyc...
And we also have an amazon listing for those who like to deal with the devil:
https://www.amazon.com/dp/B0D1LX21BP
Shot and Edited by Aaron Enevoldsen