[table]

[tr][th]rider height[/th][th]optimal crank length (mm)[/th][/tr]

[tr][td]6’0" (1828mm)[/td][td]177.5[/td][/tr]

[tr][td]5’11" (1803mm)[/td][td]175[/td][/tr]

[tr][td]5’10" (1778mm)[/td][td]172.5[/td][/tr]

[tr][td]5’9" (1753mm)[/td][td]170[/td][/tr]

[tr][td]5’7" (1702mm)[/td][td]165[/td][/tr]

[tr][td]5’5" (1651mm)[/td][td]160[/td][/tr]

[/table]

Most vendors don't state the length of the crank arms. After some probing, a vendor (I think Luna Cycle) told me Bafang crank arms are all 175mm. I need 165mm. Is it true that all kits are 175mm or are there exceptions? Does anyone sell smaller cranks that are compatible with Bafang?

I'm not necessarily fixated on Bafang. And I noticed that there exists 165mm crank arms for Bosch. I'd like to find a mid-drive kit for a 100mm bottom bracket (fat bike), and I guess I'd rather not have a seperate chain like a Cyclone has.

**update:**

I've decided to favor the Tongsheng TSDZ2 motor over the Bafang. The Bafang is heavier, draws more power, and wears out chains and sprockets faster. I just want some light assistance on climbs, so I think the TSDZ2 is better suited. I've consequently changed the subject line of this thread:

*original subject:*Bafang Tongsheng crank arms are for riders of height 5'11" - where can we get smaller cranks?

*new subject:*Tongsheng crank arms are for riders of height 5'9" - where can we get smaller cranks?

Since the TSDZ2 also has oversized cranks from the factory, I would prefer to find a kit that excludes the cranks so I buy the correct cranks separately without being wasteful.