Rear hub motor with 11 speed cassette...

[Rob Gorman]

First off, I am new and still trying to figure things out so bear with me...

I have Specialized Crosstrail Expert ((Link Removed - No Longer Exists)) that I would like to convert to an eBike. I was (and potentially may still) thinking of going with a front hub motor to keep things simple but after doing some reading, I do think my PREFERENCE is to go with a rear hub motor since they blend in to the bike a bit better but ideally I would like to continue to use my existing drive train.

So my question is, are there any 500w freewheel capable motors that would work with my 11 gear cassette? I see a lot of kits with 7 - 9 gears but none with 11 and none explicitly stating that I can use my existing cassette. I also don't want a motor that adds drag when I am wanting to just pedal normally while recreational riding as opposed to commuting to work.

I would appreciate some insight if someone else has done something similar.

 

[Dunbar]

Shimano mountain bike 11sp cassettes like on your Crosstrail are no wider than 10sp cassettes. As long as motor will fit an 8/9/10sp cassette you are fine. The road bike 11sp cassettes are wider and require a wider freehub body.

 

[Shoestring]

re: 11spd cassette, you must also have a hub motor that has a standard cassette freehub body to accept your cassette. Most hub motors have a thread on freewheel style cassette, although some hub motors are available with the freehub. I have not seen anything above a 10spd tread on style cassette, they may exist, but I've never seen one.

 

[Douglas Ruby]

I am using an 11-speed cassette on my Specialized Turbo. It came with a 10 speed. Any hub motor that claims to support 10-speed (Shimano or SRAM) "should" also work with Shimano XT or Ultegra/11-speed cassette in mountain bike or roadbike ratios. These cassettes fit in the same width as a 10 speed SRAM or Shimano casette. HOWEVER, the SRAM 11 speed cassette is slightly wider and due to supporting a 10 tooth small sprocket requires a different freewheel mechanism so it will not work.

Some hub motors are designed for earlier "7 speed" freewheel widths and are limited to no more than 9 speeds total. I have a bike at home (non e-bike) that is an old Specialized hybrid that came with a evil shifting narrow 7-speed freewheel, cassette, and derailleur. I took the 7-speed (13-30) cassette off and was able to mount my 10 speed SRAM (11-36) cassette, minus the 11 tooth small sprocket to provide a 9 speed 13-36 ratio. The cassette tightening nut holds the 13 tooth 2nd sprocket and all of the other cassette sprockets just fine. I am using my SRAM X7 derailleur, 10 speed shifter, and 10 speed chain and just block out one gear using the adjustment screws on the derailleur. The gear-to-gear spacing works fine and I just get a double click at one end or the other.

 

[Rob Gorman]

Thanks for your replies. I will check for some hub motors that support 10 speed cassettes.