BBS02 Crank Speed

What is the crank speed of a BBS02 on a 16 cell LiFePO4 Battery.
(LVC: 38.4 volts, Nominal: 52 Volts, Max Charge: 56.8 volts)

Reason for the question is I want to figure out what size cogs are needed.

The rear hub will be a Sturmey-Archer RXL-RD3 3 Speed IGH which I believe comes stock with a 18 tooth cog. The rear wheel/tire will be 24x2.0 Schwalbe Big Apple with a 24.0 inch outside diameter (and for the record a 1.75 inch width) .

I want to hit 18-20 MPH is second gear (1:1) and about 25 MPH in third (1:1.33) ... flat, level terrain. I figure that means I need about 250-275 RPM on the rear wheel for second gear and around 350 RPM on the rear wheel for third gear.

Feel free to correct my math .... :?

BBS02 AT FULL CHARGE - 80rpm (ish)

Change back sproket
front ring - 46t
Rear Ring - 14t
low gear 16mph, 2nd gear 21.5mph, third gear 28.5mph

Keep standard sproket - (this will be slow as hell to accelerate I think)
front ring -56t!!!!!
rear ring - 18t
low gear 15mph, 2nd gear 20.3mph, third gear 27mph

Grautuefel said:

BBS02 AT FULL CHARGE - 80rpm (ish)

Click to expand...

Thank thee :thumb: :thumb:

LewTwo said:

Grautuefel said:

BBS02 AT FULL CHARGE - 80rpm (ish)

Click to expand...

Thank thee :thumb: :thumb:

Click to expand...

My BBS02 ran way faster than that on 48V. Like 130ish RPM? Faster than I could spin with the stock 170mm cranks. I had an easier time keeping the motor in its happy place once I fitted 152mm cranks.