clyte 3548 or 9c 2805 in a 20" rim

[izeman]

i'm considering doing a 26" mtb conversion into something with 20" wheels. setup should be 72v20ah and a dd motor.
so i have looked at the crystalyte 3548 or an 9continent 2805. both should reach the same speed of nearly 60km/h.
the advantages i see are:

2805
.) lower power consumption
.) no overheat
.) better price

3548
.) higher quality?
.) more space for break caliper

anything else? which one would YOU choose?

 

[dogman dan]

Me? the cheaper one. The watt limits of a pushed 9c are enough power for me in most cases.

Clyte is supposed to tolerate a bit more though, so that should be your real decision point. Much above 2000w, the 9c is in a zone where it can be melted if the ride is long enough.

In a 20" rim though, either motor should tolerate a lot more than in 26" rim.

 

[Drunkskunk]

I pulled them both up on http://www.ebikes.ca/simulator/
it took a 35A controller to hit 59kph, but both motors are so closely matched that it essentualy makes no diffrence. both would be running at ~2250watts, and Justin's simulator predicts neither would ever overheat at that level on flat ground. Stick in a 10% grade, and the 9c hits overheat in 11 minutes to the Clyte's 17.

sorry, can't post a screen shot from work, but its worth plotting both at the same time on your own.

If it was me, I'd pick the 9C over the Clyte, for weight savings and cost.

 

[izeman]

@drunkskunk: i did the very same thing that's why i'm not sure if it's worth buying the more expensive one as they seems to be quite equal (on the power side).
a definite plus is the more space you have for the disc caliper with the clyte. on the other hand i could invest those some $100 more into a better/smaller brake and go for the 9c.
questions over questions ...

 

[dogman dan]

The question would then be, do you need to climb that hill? If yes, then get the clyte so it can climb it longer.

Bear in mind that the sim doesn't include your pedaling, which can significantly increase the time to overheat by lowering the load and increasing motor speed. So if you'll get to the top of that hill in 10 min, you should still be ok with the cheap motor if you pedal hard for that 10 min.

 

[electr0n]

One of the things that swayed me towards the Crystalyte was the way wires exit the axle. It makes it easier to upgrade the phase wires, add a thermometer or repair hall wires etc. If you want to go much above 4kw peaks later on and push the limits of continuous power it's something to consider.

 

[izeman]

ok. that, together with the wider brake mount tosses me into the clyte direction.
thanks guys!
now i only have to see where to buy those a123 20ah pouch cells ...