OwnerJeffrey P. Kloth
Owner's Other EVs1974 Volkswagen Beetle
1982 Honda GL500 Interstate
LocationChandler, Arizona United States map
Vehicle1973 Yamaha TX-750
Fairly rare old-school bike since the I.C.E motor was not so good and nobody restores these...
MotorBriggs and Stratton Etek-R Permanent Magnet DC
I blew several "Etek Originals" in my testing phase. I like the new "R" so far...
DrivetrainANSI 50 Chain. Front Sprocket: 12t Rear: 72t. Had to change sprockets to other side of bike (rather than use jack shaft) so Etek spins in proper direction--Yes, it does matter, unless you like changing brushes. Note: Now it does not matter with the Etek-R
ControllerAlltrax 7245
450 amp programmable set to 200
Batteries384 A123 Systems M1 and Sony mixed, 66.00 Volt, Lithium-Ion
Main pack with 192 M1 cells from DeWalt packs: 12p16s @ 27AH. And 192 Lithium Manganese 26650 Sony cells
System Voltage66 Volts
ChargerVicor power supply(s)
I have several options but can charge one of the 12p sub packs in less than 20 minutes with 80 amps at cell level
HeaterYet to be found
DC/DC Converter DC-DC converter or turbo 12v battery
12 amp DC-DC converter
InstrumentationOrig Speedo and odo. Digital bike speedo/computer
Top Speed53 MPH (85 KPH)
On the flat
AccelerationVery good--keeps up with cars. New fan cooling motor all the time @ 220cfm/.4 amps and worth it...
Range35 Miles (56 Kilometers)
Actual tested reaching speeds over 30 mph many times, stop and go city driving and HILLS.
Watt Hours/Mile80 Wh/Mile
EV Miles
Current:675 Miles (1,086 Kilometers)
Seating Capacity2 adults
Curb Weight285 Pounds (129 Kilograms)
Estimated weight. Motor: 22lb, main pack: 40lb (cells in sub packs inside Craftsman toolbox--yes, gets lot of looks!) No more toolbox as of 6/08
Tires26" Full diameter Standard for this MC. Over-inflated
Conversion Timeover a year of tinkering
Conversion CostOver $2k in the money pit!
Additional FeaturesThe bike is very comfortable. Originally I had lead-acid so needed bigger frame/roller. Its old-school looks turn heads--especially when they see no pipes! I am still messing with the conversion but it is now registered and in use. I am working out the charging/battery managing at the moment. It is so fun to ride. I can add range/batteries and it carries two well.
Be realistic about speed, range, costs and all the gotchas of a conversion. This site helped me and my son (Eddie, "Bike to the Future") make some sense out of where to start the EV journey. The journey ends with an "EV Grin".

4/18/08 Changed motor to Etek-R Not much has been said about this new motor but I thought I would tell about my findings. I am able to directly compare on the same vehicle, with an original Etek. As you know the "R" in Etek-R is for "replacement". So how does it do?
First off it bolts right up as the face and shaft are the same. The R is a bit longer so beware if you don't have space. Fortunately the motor can run in either direction with no issues. There is an internal fan that sucks through the end-bell in counter-clockwise mode and blows in the clockwise mode. I found I wanted to add an electric fan because the motor can get pretty hot (I am running it at 60 volts when the pack is fresh). That being said I have put about 45 miles on the motor and can say I really like it! The bigger more standard armature design is a better heatsink and there is no sill epoxy interface to trash like on the old axial motor. In my tests it did seem a bit less efficient and ate a few more amps over-all. Power feels the same but the "powerband" feels smoother and pulls well at all RPM's. I obtained the exact same top speed from "Deep Cycle" as before. I am very happy with the motor and with the fan I added (48v @.25 amps) it ran cool even with a hilly run on a 93 degree day. Having owned 4 of the original Etek, and the troubles I saw (though I was going over-spec), I can see why they discontinued them. I am glad they made this new model--a morph between what is good about the Etek clasic and the standard PM motors. Another good thing is it is still fairly light at around 30 lbs. It is radial. The commutation is fairly standard. I have not had the motor apart but was told by John Fiorenza., the designer of bothe Etek and Etek-R, that there still are copper bars inside for the coil loops, not wire like a standard armature. Another observation I forgot to mention,,,the brushes look smaller and the motor is less noisy. Etek-R is not the official name, rather it has a model number ME0708 and the Etek-RT (more torque, higher voltage rating and lower speed), model ME0709. The Etek-RT is a bit longer. The motor manufacturer is Mars Electric: WebPage They are also sold by the major EV and Robot parts dealers. John also told me he regretted that the original Etek had less width to the bars (less heat dissapation?) and so the new Eteks have wider bars. Folks using any Etek with a mosfet controller should be aware that these motors present an almost dead short to the controller. Alltrax has a bullitn about what to do to combat this. The Etek-R amp rating seems to be in flux--I have seen continuous ratings for 100, 125 and 150 amps. I was set at 150 amps for my tests but remember I had an added fan... Brian from Thunderstruck Motors reported to me that at 200 amps the motor felt very hot and "smelled bad". Again, we are pushing the specs. I have had no smells and today will test at 72 volts... Oh, and another observation--the motor has very nice Japanese bearings.

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