will set for lower current like 15 amps cont to 20 max so I increase my range and try to take advantage of low wind resistance and low weight. I only weigh 76 KG I I can lose maybe a few LBS so the whole light weight concept is well worth a try. SO I will try a light weight aluminum frame the light GM 48v pack and alloy gear. I will go Kmart for cheap. It would be good for my Wife or me out and about. I this want bike to be a GM gallery bike.
I'm not sure you will be impressed @15amps continuous, However each person is different. For me 35amps on take off gets me up to speed quick and it consumes 17-20 max on the level. @30 miles full throttle I still had around 5 amps out of my 20 amp ping, with a few steep short hills. people going up long steep hills will probably get less. (maybe)
This is the funny thing I have noticed, The slower I go up a hill the more the motor consumes, the longer it takes me to get up. If I have lots of amps on take off I will go faster up the hill, and therefore, will get me up to the speed quicker, and I will consume less amps, once up to speed. I'm not sure I can explain it properly, but to me it is not more efficient to set less amps!
15a continuous will be more impressive on a Pie than it will be on a HBS.
One may think whats the point in getting an MP if the HBS 48v is faster than it.
I assume a Pie in delta = a hbs48v 1000 watt in wye, right? Think about a Pie in wye with 60v compared to a a HBS at 60v, then both at 72v. The speed advantages will start loose appeal with the HBS and the Pie will hold against the wind better at high speed for a few more amps..
More torque and less speed at the same voltages.
I truly believe the at 48v MP has got 12v less speed potentiality with approx 25% more torque over the 53kph HBS48v 1000watt, The performance gains the Pie has is derive from the longer windings and not thicker windings.. The Pie has a longer magnetic pulling arm so the volts per amp can be put to use not so much as the amps per volt..
The only thing that is slowing the hub on hills and on take offs is the weight, right? If I can build a bike that has very little weight and I weigh 73kgs, then 15 amps may seem a little more impressive.
If I load the bike to the max with a trailer, I want it to slow down. Rather this than a melted motor.
The only thing that will be in my way is wind. That's what the pedals will be for with the 26" build I plan. I expect pretty much full speed on the flats and the same speed on hills with some pedals. I expect that the pie torque will out perform either of my HBS hubs at a similar amperage on the hills.
I have mentioned I have only one climb and this is to the end of my journey where the battery is more vulnerable to be pushed hard, other than this it is very flat where I live.
Try doing a hill start with 15 amps and compare the same hill start with 30 amps and see which one uses more watts. The motor makes gravitational potential energy on it's way up, The speed can be regained on the way back down a hill but not much can be re-gained if that speed is at maximum at the crest. You only save time.
In some aspects you are right but in others I may be right. Watts per distance are what you should be looking at to see what actually uses more capacity not just the amps going up a hill.
With the 20" it could be hauling over 200kgs I will need the 20" to convert all the volts into RPM which is better torque in the take offs on the 20" and use the amps to keep it there. The higher RPM will allow more internal air flow inside the motor and the speed will be higher under load so more air flow over the outside of the motor at a higher RPM will improve my cooling.. Even on the 20" I suspect the amps I will draw with normal riding will not be so demanding on hills but the over all capacity will be effected by using the capacity to generate the higher RPM. The 20" on the flats may not be so efficient as a 26".
The questions remain.
At what load does the 26" Pie start to loose its grip of the magnet poles accumulating in power losses compared to a 20" MP. And how much more energy does the 20" MP loose doing more RPM for the same distance traveled compared to the 26"MP.
