Recent content by johnb

Great work Justin! I am curious as to why you don't stock Bafang motors as they are quite well respected, perhaps more in Europe, where power and speed is more restricted, than in America.

I'd be tempted to drill some holes exactly on the seam and then insert some pins to prevent rotation.

Not just intuitive I think. A loose fitting spanner will quickly round off a nut with only a little torque. With a tight fitting spanner you can apply much more torque to the same nut. Why is it not the same with torque plates and axle flats? From a physics point of view, I would say that the...

It was the newer 3/16" type. I only had it a couple of weeks. I think it is important how good the plate fits the axle. As with a good fitting spanner you can apply much more torque. Of course this is difficult if axles are not made to a close tolerance. I also think that pre-loading the...

Justin, your post was just a few hours late for me. This is exactly what happened to my torque plate yesterday (one I got from you). I have a 9C motor running at 38V 12A. I have to admit that I was probably to blame as I noticed the day before that they nuts were loose. Of course I tightened...

A survey of the literature reveals that bicycle models generally include a knife-edge rolling point contact whereas motorcycle models include toroidal wheels. This appears to confirm what I suspected about the relative significance of the tyre profile.

You will have to excuse me for still being sceptical about this. It may be that it is a major factor on a motorbike and a minor factor on a bicycle. As you say, it depends on speed. I think I would need to see some maths to be convinced. Actually this is perfectly possible (if a little...

Perhaps I have misunderstood you here... Are you saying that this is the only turning force on a bike, a major factor or a minor factor? I'm not sure about a motorbike with fat tyres, but I would suggest that it is at most only a minor factor on a bicycle. Lean is obviously necessary to...

To get up that hill you need at least 122 * 15/100 kg of thrust ie 18.3 kg or 179 Newtons. In at 24" wheel, that equates to 55 N-m of torque ( that's at 0 kph :lol: ) With a little more torque you can overcome some rolling and air resistance and go up faster.

Do you mean that both red and green lights are on at the same time? If so, that doesn't sound right. Normally the red light is on when charging and the green light is on when it is not. The red light may come on again for a while (as mine does) while the cells are balancing. I leave mine on...

I guess the reason why water and MOSFETs don't mix is that because their gate current is so low, it doesn't take much of a conduction path (supplied by water) to turn them on at the wrong time.

Totally agree with the rant. I'm in the UK and it rains here a lot. My controller got wet and went crazy before I 'got around to' sealing it. It's not the same controller as yours but probably the same case. Anyway, I fixed the controller and took it out of its case and put it into a cast alloy...

That 80% efficiency figure quoted in the reference is for the capacitor only. My 25% figure was calculated for the motor/generator only. Adding the capacitor figure would give an overall efficiency of 20%. This is for a bike with typical direct drive motor. I can believe that a HEV with a more...

You are right, power MOSFETs do have that feature. So you are expecting to recover 70% of the acceleration energy when braking. I don't see any way of getting more than 50% efficiency during acceleration and regen, giving an overall recovery of 25%. Have you been using...

I don't see that being a problem. When the controller is not activated, the MOSFETs will not be conducting so will not allow current to flow to the cap. That's assuming the the throttle is switched off once you run out of motor push.