C=2PiR = circumference where R=20"/2 (units of inches) Cin miles = Cinches x (1ft/12inches) x (1 mile / 5280 ft) 25mph/circumference(in miles) =rev/hour rev/hour x 1hour/60min = rpm
Better check me, I get 335 RPM at 20mph and 419 RPM at 25 mph 36 volts will get you less torque than 48 volts. Pprobably not a problem with a light bike like a Bike E. It will be quite tricky to lace such a wheel up as the spokes will have to be very short. Consider radial lacing (no crossing spokes). Honestly, I think you would be better off rigging up a mid drive. You might be able to mount a tandem cranks with an additional left side sprocket and run the motor to that. Sling the motor below the center of the frame somehow. This way to maintain the ability to shift gears in the back with both the hub and derailer. THis might make motor selection easier. The small rear wheel rolls out less per rev and most motors are designed for a larger wheel - therefore slower RPM than you want. Also, in my experience you will want to try to keep up pedaling with the motor - the gearing will be handy for this. And you have a useful back up plan if the batteries or motor cease working for some reason. On Sat, Aug 13, 2016 at 5:29 PM, ken via EV <[email protected]> wrote: > I have a Bike E with 20" back wheel . Where can I find a reasonably > priced wheel thats desgined to be effeient for that RPM / 20- 25 mph > and 36 volts. > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Read EVAngel's EV News at http://evdl.org/evln/ > Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/ > group/NEDRA) > > -- To invent, you need a good imagination and a pile of junk. Thomas A. Edison <http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html> A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 585-6737 Land (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Mobile and Google Phone [email protected] <[email protected]> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20160814/e360395d/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
