Shimano Alfine 8 vs 3 speed Sturmey Archer for mid-drive?

Rykmann

New Member
Region
Canada
I have a 1000w Bafang G510 48v mid-drive, with a Gates CDX belt drive, 26” x 4.8” fat bike. The bike came with a 5 speed Sturmey Archer RSX-RK5 which lasted about 2 minutes into my first ride.

The company I purchased the bike from Suzhou Ansbern Sports Co., Ltd. did not honour their warranty so I am looking for a replacement IGH.

The bike shop recommended the Shimano Alfine 8 (which is back-ordered to March 2021). However in this interesting article written by Ron/spinningmagnets https://www.electricbike.com/mid-drive-kit-igh/ he suggests that if you are looking for a “bulletproof” IGH for an axel length greater than 135mm the 3 speed SX-RK3 is the way to go.

Sturmey Archer says that their IGH’s are not designed for mid-drive motors, so my question is, has anyone had experience using either of these IGH’s with a mid-drive motor?
 

E-Wheels

Well-Known Member
The Shimano SG-C7000-5D IGH is designed for ebikes
 

Rykmann

New Member
Region
Canada
At 135 mm I think the axel will be too short for a Fat Bike. My current axel is 185 mm.
 

Ravi Kempaiah

Well-Known Member
Region
Canada
City
Halifax
@Angela M. and @ebikemom ,
Could we please move this thread to parts and accessories?
Thanks

Sturmey Archer says that their IGH’s are not designed for mid-drive motors

This is true.

he suggests that if you are looking for a “bulletproof” IGH for an axel length greater than 135mm the 3 speed SX-RK3 is the way to go.
Because if you are in the second gear, then you are using a 1:1 gear ratio and you could pass quite a bit of power through it.
I believe it comes in 170mm fat bike sizes as well.

If you have the means, you should just go for Rohloff.
check this out:
https://www.cyclemonkey.com/blog/su...e-rohloff-speedhub-50014-and-gates-belt-drive

1608515429363.png


A 3-speed Sturmey archer hub may not have enough gear range but some people have had luck using it with high Bafang mid-drives.
Not sure if the 3-speed sturmey archer can take Gates belt drive sprocket. So, you need to research that aspect as well.
 

greeno

Well-Known Member
Region
USA
City
San Diego
I have been running a SX RK3 Sturmy Archer IGH for a little over a year and love it. Bike is a Surly Wednesday with a BBSHD motor. 36t chainring on the front and a 20t cog on the rear. Rear dropout is 170mm. Funny size rear axle as I needed to get some 12/10 reducers from surly because the dropouts were to big and the axle would pop off sometimes. I ended up making a rear axle bracket that bolted to the frame to keep it secure and all has been good.
IMG_1174.JPG
 

Antonella

Member
Region
USA
City
New York
How about a 250 watt mid motor with a vintage AW S/A rear thre speed hub on a classic Raleigh for the sixties?
 

Attachments

  • E676267D-2D0A-41B3-9260-C1E0C6A4E1FA.jpeg
    E676267D-2D0A-41B3-9260-C1E0C6A4E1FA.jpeg
    501.2 KB · Views: 114
  • 48EE5F3E-5D58-41F6-854F-FC360BA4A844.jpeg
    48EE5F3E-5D58-41F6-854F-FC360BA4A844.jpeg
    476.3 KB · Views: 107