Hello From the Antipodes

[ausGeoff]

G'day from downunder...

I live in rural South Gippsland in the state of Victoria, right down
on the southernmost tip of the Aussie mainland, next to Bass Strait.

I've owned three two-wheelers, and now have a tricycle. I was,
I guess, happier riding those, but I'd fallen off a couple of times
on two of those bikes, which led me to this trike.

I do have a couple of questions about the drive train. The trike has 3-speed internal
twist-shift gears, mid-drive motor, and 5# PAS selector. So... I ride primarily on smooth
flat gravelled trails and sealed roads, and I'm a bit confused about the gears v. PAS
settings and/or their ideal combos. I'm a lazy bloke LOL so I tend to nearly always stay
in PAS #2 and 2nd gear.

I don't really understand the power/torque figures for the various PAS/gears combo,
or if I'm treating the trike kindly.

The trike weighs 35kg and I weigh 99kg, with the motor being a Bafang 250 watt (max
legal here). Should I be utilising the gear ratios more, and or different PAS settings as
I ride on gentle grades or against the wind etc? Or is my lazy man's way good enough?
It doesn't have a throttle (again, illegal here) other than a 6km/h walk assist.

Any thoughts much appreciated.

 

[Jeremy McCreary]

Mid-drive motors tend to be most efficient at higher cadences (pedaling rates) — say, above 70 rpm. More efficient here means that more of the applied electrical power goes to forward propulsion and less to heating the motor. So for given ground speed and conditions, more efficient also means greater battery range.

Every rider has their own preferred cadence as well — usually in the 60-100 rpm range. Pedaling at your preferred cadence is generally more powerful and less tiring. Also easier on the joints.

On mid-drives, the gears are largely there to help you pedal at the best cadence compromise between the motor's happy place and your own. If you maintain a fixed speed of, say, 10 mph, changing gears changes only your cadence. Why not make it one you and your motor both like?

So one approach to try: Start out in a lower gear to limit the load on your drivetrain. (Same idea as not lugging a car engine.) Then coordinate the gears and assist levels to keep a good cadence as conditions change.

With the focus on cadence, you'll soon figure out how to play the game. I tend to ride at low assist and use first the gears and then assist level to keep my cadence. But the other way around also works. Matter of taste at that point.

 

[ausGeoff]

Thanks so much for this informative—and timely!—response Jeremy. I'd never
thought about any relationship with cadence, so I'll give it a go tomorrow.

 

[DaveMatthews]

Welcome from Vancouver Canada mate!