Wednesday, September 21, 2011

Street fighter build

We have had these rollers in the shop for a while just waiting for a time when we could build them up. With the Dual motor setup being a best seller we needed a demo bike to show off what the DU-600 series motors could do and how they look. So we took a GPRS extended the swingarm (150mm) and turned it into a street fighter style bike.

She is far from being finished but here is the bike outside after the first Frankinride using a 500 amp 144 volt Kelly controller. with a 96 volt Lipo pack capable of over 300 amps

Lots of work still needs to be done to make her a proper show bike but the foundation is there.
Customer reaction:
Two motors in a light weight frame = fast of the line

Thursday, September 8, 2011

Race #2 Winton race track

EnerTrac continues it's sponsorship of the Catavolt team and Thanks to Andy of we have a great video of the race event

Monday, May 9, 2011

Multi speed motors and gear boxes

Now the question
What if you want to accelerate well and go fast?

lets all agree it takes the same HP to go say 100MPH regardless if there is a gearbox, multispeed motor or not

So there is no free ride here if the motor can't put out the power no gearbox or multispeed motor is going to get the bike to speed.
The power plant needs to be in a proper operating RPM to be efficient and output the power needed for the speed required.

If you have a wide torque curve as most electric motors do then maybe you don't need a gearbox or multispeed motor but even an electric motor has a most efficient RPM and that is up around 60 to 80% of the max RPM (BEMF) So even thought a gearbox may not be necessary, it will result in more HP because the motor is operating in its most efficient region. For a multispeed motor implemented correctly this is also true. Since a high wind count motor has more amp-turns it has higher torque for the same current (which will result in overheating if sustained) or half the current for the same torque (the correct way to look at it) but it trades speed for torque and will be voltage starved at half the RPM, So the 60% of max RPM is reached early and so does Max efficiency. Then if one switches to half the turns and doubles the KV of the motor it is now possible to get higher RPM and again achieve max efficiency.

In Conclusion more power is achieved with both the gearbox and the multispeed motor because the motor is spending more time at higher efficiency really no other reason, but the gearbox has losses that make the gain in motor efficiency sustainably less power to the tire. The gearbox losses are not present in the multispeed motor design.

Saturday, April 16, 2011

MHM-602 race motor

EnerTrac is sponsoring team Catavolt
here are some pictures of the bike.
More to report as the bike goes on the Dyno, then raced in the TTXGP
Here is my thinking The bike that has the best batteries and holds more of them wins

Team Catavolt is using excellent batteries and with no motor in the engine bay the bike can hold more of them

Tuesday, March 22, 2011

She is still pretty

I'm back on the bike Oh glory its good to be riding again. The Lipo boost pack is proving out well, I'll have more data shortly. What has been speculation as to road performance and only measured on the Dyno is now fact. The Lipo pack starts sharing current at 60 amps at 100 amps the balance is about 60/40 and I've seen peaks as high as 80 amps from the Lipo booster. On the highway at 60 MPH and 80 amps the Lipo pack will contribute 20 amps. Temperture just isn't a big factor in how the LIFEPO4 and Lipo packs share current.
Just to Review
This Motorcycle started life as a New Lifan 200
34 cell 40AH Thundersky LIFEPO4 pack 115 volts fully charged
Boost pact Diode summed 25 cell 10AH Lipo pack with contactor disconnect
 Boost pack schematic
BLDC (5RPM/volt -10RPM/volt) 10KW, 30KW peak Hub motor with two speed winding and on the fly switching
Kelly Controller KBL12401I adjusted for 250 amps peak
350 pounds
65 to 70 MPH (Depends on tire size and voltage)
0 to 50 in about 6 to 8 sec. (Depends on tire size and current)

Miles to date on the motor over 4000
Miles to date with two speed winding 1000
Miles to date on rotor spokes rim and magnets over 5500

Can she be duplicated YES is she cheap NO