Wisper 905 resists change.

[Vikki]

Don't know whether it's my imagination but I've noticed something rather good about my Wisper. My old Powabyke Euro 6 had a brushed motor and when riding into a stron head wind the speed used to drop quite dramatically to about 12mph or less and I had to pedal quite hard to maintain a slightly higher speed (13.5mph). If I stopped pedalling the speed would plummet. This is understandable.

Bikey, however, seems to resist the speed change. Sure, it drops but even with moderate pedalling I can maintain about 13.5mph. If I put in the effort I had to on the Powabkye I can achieve 14.5 to 15.5. Can't keep that up for long, though. It seems that brushless motors attempt to maintain their speed against the odds. Different technology, I know. Is this attempt to (almost) maintain speed inherent in the design or is it the controller that attempts this? OR... am I imagining it?

But, the Powabyke is still an impressive beast, I wouldn't want to take anything away from Old Faithful. There's room in this world for all the little beauties

Best regards.

Vikki.

 

[flecc]

It's in the design Vikki. The Powabyke motor has it's coincidence of maximum torque and power at about 7 mph, so speed drops quite a bit towards that under high loadings. Its that lowish speed that makes them such good climbers for such heavy bikes.

The Wisper's motor has it's coincidence of maximum torque and power at more like 10 mph, so the drop in speed under that wind load is less.
.

 

[Vikki]

Many thanks, Flecc. So I'm not dropping the odd marble here and there then

I must admit to helping my bikes out quite a bit if I can because I don't like stressing the poor things. I supect they can punch more out than I think they can. For instances, if I'm holding the throttle flat out and wind resistance drops the speed noticeably I tend to think the poor critter might be working too hard and I give it more of a hand, but (other than battery drainage) do I really need to worry about that? Am I being kind to my bike rather than my bike being kind to me? Is the bike happy punching through a head wind at 11 or 12mph or would that be torturing it?

Best regards.

Vikki.

 

[Mussels]

Many thanks, Flecc. So I'm not dropping the odd marble here and there then

I must admit to helping my bikes out quite a bit if I can because I don't like stressing the poor things. I supect they can punch more out than I think they can. For instances, if I'm holding the throttle flat out and wind resistance drops the speed noticeably I tend to think the poor critter might be working too hard and I give it more of a hand, but (other than battery drainage) do I really need to worry about that? Am I being kind to my bike rather than my bike being kind to me? Is the bike happy punching through a head wind at 11 or 12mph or would that be torturing it?

Best regards.

Vikki.

Since I got my bike I have gone almost everywhere with the throttle pinned, I have only broken the spokes so far so I don't think you will stress the motor too much.

 

[flecc]

No, you don't need to worry Vikki, the only ill effect of punching into head wind is shorter range, the battery's BMS looks after it and protects it from harm.

P.S. Crossed with Mussels reply.
.

 

[Vikki]

Thanks guys. I'll feel more comfortable now knowing I can let Bikey work a bit harder in those winds because my left knee has been complaining about the effort I'm putting in to spare Bikey. I can afford the power since when I get home the battery is indicating half full (probably a bit over half full). Loads left over.

Old faithful did require additional help otherwise the battery would be flat before before getting home.

I like the pedalling action where I'm comfortably assisting with no real pressure on my knee. In other words - just slightly above legs idleing. Almost no effort, an easy action. I would like to keep that easy action into the head winds and you've both given me the confidence to try it. Doesn't matter if the speed drops a little.

Funnily enough, I find riding easier when I'm pedaling than when not. When I don't pedal it seems I'm more conscious of steering the bike and a teensy-weensy bit less stable. I also tend to put weight on one straighened leg and ease my rump slightly off the saddle. Gives my rump a breather.

Best regards.

Vikki.

 

[torrent99]

Funnily enough, I find riding easier when I'm pedaling than when not. When I don't pedal it seems I'm more conscious of steering the bike and a teensy-weensy bit less stable.

Yes it's concept we call "dynamic stability" in kayaking. Essentially each pedal/paddle stroke gives you the opportunity to correct your balance. By continuously moving you are continuously correcting your balance...

 

[john]

A brushless motor (all else being equal) will typically maintain speed better than a brushed motor due to it's lower internal resistance. This means that for a given drop in speed, more current is drawn.