My Ride

[disadvantage]

The BMC motor axles are M12 x 1.25

Crystalyte motor axles are M14 x 1.5

 

[knoxie]

Hi

Kudos on the torque arm! liking that nice and simple and looks very strong!! thanks for posting the design may knock a couple up myself, stainless will be nice! harder to machine though!! I will knock one up out of some mild steal and paint it using acf-50 on the bits where there is no paint, that stuff stops rust dead!

Hey and way cool with the BMC drawings! don't suppose you have one for the inside as well, I am trying to get some gears sorted as the ones on my bike are worn and slip under load, I have pictures and detail of the gears so I should be able to get a set sorted, they are nylon with metal side plates and a press fitted bearing, will probably have to buy the nylon gears and press fit the bearings, I will then simply cut some metal or drill out the old ones and pop rivet them to the gear faces to strengthen them up.

Thanks again for the pics of your bike, way cool!

Knoxie

 

[disadvantage]

Thanks for the comments Knoxie!

Sorry, I don't have a mechanical drawing of the internals of the BMC motor. Have you tried contacting the factory directly?

I connected my new Watt's Up meter for the 5 mile ride into work today. Here's the statistics I got with a 48V 20A controller:

2.820 Ah used
102.5 Wh used
21.63 Ap peak
35.44 Vm minimum, 10s lipo pack
778.5 Wp peak

I'm building a new battery pack from Moli cells. I was debating whether to go with 3p or 4p. Now that I see my current drain, I think I will definitely go 3p to save on weight. Then I can build two battery packs, and parallel them when I need more range. This also gives me a back-up battery pack, and I can dabble in solar recharging.

Knoxie, is it true you use solar energy to recharge your ebike batteries? If so, do you recharge from the solar cells directly, or are you converting to house current and then back into DC?

 

[lazarus2405]

Mmm, I highly recommend the Molis. If you have any issues, give me a shout.

With that current, you could very safely do 1p. For a while I regularly pulled 55a continuously from a 2p setup, though doing so got them a little warm. So, you could make that pack as small as you want without sacrificing power. It just depends on how much range you need.

 

[Roonster]

Great looking bike!

Was the BMC motor black when you received it or did you paint it? The one I received is silver, I think I prefer the look of yours

 

[disadvantage]

Today I got another set of statistics from a long, roughly 20 mile ride:

10.401 Ah
372.6 Wh
22.07 Ap
31.48 Vm
828.9 Wp

The bike was kinda frisky today. I got 22 amps peak and 829 watts peak out of it.

However, after this ride, the battery pack was quite warm. I let it cool before recharging. It's my understanding that li-ion fires are self-supporting with their own fuel and oxygen. All they need is heat to get started, and once they have, you can't put them out.

Judging by the 31.48 volt minimum, I probably came close to draining the pack completely. It wouldn't surprise me if the cells are stressed and have lost some capacity.

I must get my Moli pack built soon. I sure wish the Bob & Gary BMS would become a reality soon.

 

[disadvantage]

Was the BMC motor black when you received it or did you paint it? The one I received is silver, I think I prefer the look of yours

Roonster, I asked Doug Canfield of EV Tech to paint the motor for me, before he had it laced into a rim.

 

[Mark_A_W]

The motor in the rear wheel is a BMC from EV Tech.
http://www.texaselectricbikes.com/catalog/brushless-geared-motor-p-163.html
I changed the wires inside of the BMC motor to make it work with Crystalyte controllers, turning it into a Puma motor. My previous bike had a front 5303 Crystalyte motor, but I like this one better. The BMC is half the weight of the Crystalyte, so my bike rides better and is more maneuverable. The no-drag freewheel allows me to coast silently past other bikers and pedestrians. The geared BMC motor provides lots of torque for climbing hills, much more than the Crystalyte.

Just curious Disadvantage, what exactly did you do to the wires to allow the Crystalyte controller to work?