Pretty close to ordering a Grin All-axle. Advice?


1 W
Jul 30, 2023
I’ve gotten intrigued in recent days with a direct drive front hub motor with regen. I live in a pretty hilly area and even my “acoustic” bicycles have had days where the brakes are burning. In my research, the grin all-axle direct drive should have relatively acceptable weight and the improved torque arm innovation should make it good as well.

I’m a road cyclist so I’ll likely install it on a road cycle of mine with front thru axles. The fork is carbon but the torque arm should be fine from the anecdotes I’ve read.

I”m thinking I’ll just order a ready to roll kit. Probably do the wheel build because it’s really cheap at $20, while lacing a rim can take hours in my experience. I’m thinking the 14.5ah 48v battery too, and probably a cadence sensor to be fitted at the bb.
Best get two torque arms from Grin too, because theirs are the tightest fitting ones I've come across yet. I consider Grin arms a crapshoot when used with a plastic fork, but any others almost certain failures.
I have the all-axel on my old k2 crush full suspension mt bike. It is the rear model. I also have a new specialized 29" rock hopper hard tail with the GMAC grin setup. The all axle puts out about the same power as the GMAC it seems to me but it runs much (10-15 deg C) cooler than the GMAC. The regen braking is a real game changer. I was riding the hopper to day down a 6% to 16% grade, it slowed it down to 8 mph on level 2 regen. Level 5 will stop the bike.
I wouldn't personally do the front hub, too many weird handling issues , like spinning the front wheel while leaned over on wet pavement. Something to think about. I had a e-bikeling on the crush front until I sold it and got the all-axel for the back.
Been running a front all axle w regen for the past 2 years in a surly disk trucker. No issues or problems, real nice motor. Is it better than the 9C? Yes but $300+ better?, IDK. Had a front mounted 9 C for 10 years prior to that and it worked fine also. The newer ones (9C) look even better. It is a lot easier to get the all-axle on and off the bike, and its lighter. Did end up damaging the forks on an earlier bike with the 9C due to installation error, couldnt have happened with the all-axle. Steel forks so just pinched them closed in a vise, still unwanted aggravation.
A high power front motor will spin on wet pavement, something to watch out for and maybe a reason to consider a rear motor.I got the "standard" wind which is probably too fast for me, tops out at ~ 33mph. Not really sure what Im giving up with that wind, not low speed torque according to the simulator; but I just dont understand how? More torque would spin easier anyway. Good luck with your build! Hard to go wrong with grin products.