Step 11: Conclusion - UPDATED!

Picture of Conclusion - UPDATED!
The final layout and design of the bike was ok, but needed some work. After some time on the road, we decided to make some modifications. First to go were the four big, mismatched 80Ah batteries. These were never a good matched set and always caused unreliable performance. I decided to replace them with four sealed, golf cart-style 50Ah batteries, which were smaller and lighter, but stored less energy.

However, the new batteries were small enough that all four could fit into the engine compartment - eliminating the two heavy rear saddle bags ( and all that weight). Using smaller gauge steel and gigantic zip-ties to build the new battrey trays saved even more weight. Sadly, the new design meant there was no room for the cooking pot that held the electronics, so those had to be remounted in an available spot.

The final design looks cleaner, weighs a lot less, but holds less power - a trade off that didn't result in much change in the speed or distance of the bike, which always fluctuated around 35-40 MPH, and 15-30 mile range per charge.

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andy.knote8 months ago

Step 10, wiring- You had 4- 12V batteries in series, could you not have tapped 1 battery for 12 volts? I've tapped 12 volts off one battery in a vehicle that used two 12V batteries in series for a 24Volt system...

Still a cool project.

rebel diy2 years ago
sorry but i hade to comment on this it maby cleaner but it only goes 30 miles i can do 30 miles on my rebel wich is good old fashion petrol and i can get 180 to 200 miles on a tank
surly making the bike electric wouldnt be cost efective as the battarys will cost a lot when they stop holding a charge
it seams a bit pointless to me
criddifer5 years ago
you could put a car altanator with a toothed gear on the shaft with very little friction to turn it to charge the extra battery for the light and other normal eletronics on the bike and it should work
Think about it. Even you reduce all the losses associated with driving an alternator to zero,it's the vehicle's drive battery that would be providing any energy an alternator would provided. May as well use the added weight to increase battery capacity
bodo6 years ago
cant we use something like bicycle dinamo to get the bateries charged?
sparkyrust (author)  bodo6 years ago
Actually no. Anything which uses the bike's motion to capture energy is offset by the friction and drag created, so you actually lose more energy this way. Thnaks for the comments!
besides that, the dynamo would have to have it's power converted to DC to charge the battery.
Not that I'm saying a dynamo on an electric vehicle is something that's sensible, but most dynamos output DC without a need of outboard conversion
Bosun Rick4 years ago
Has anyone considered using a HYDRAULIC (think Hydrostatic) drive with an Electric motor?

No drive alignment issues, just hoses, a pump and the Hydro motor

See www.hydraulicinnovations.com for details. Their unit is larger and heavier duty than this project would require, but the concept would be the same.
Hubiewan5 years ago
Hubiewan asks:
Why not use the original gas tank to store the electronics, thus keeping it looking like a regular bike?
eron silva5 years ago
Dear friends, is it possible to use a car dynamo (without the AC converting part) as an electric motor for a bycicle conversion?
* I could get a used one almost for free;
* a car dynamo weights 12 kg, but some of it could be shaved off (unnecessary handles, installation arms, perhaps - maybe a half kilo or more...).
JTurner3856 years ago
Is it possible to get all of the needed parts for the conversion from a used 48v golf cart? The thing is, I am in Mexico and the sources for most of the parts are in the US. I can have them shipped but it does cost a lot and i am worried about customs fees. Any suggestions?
Arayas6 years ago
Hey guys looks it turned out really good -excellent project! I've been considering converting a bike for my senior project. Any chance you could post a rough estimation of the costs? Also, I would love any info you could provide on where one might be able to look up / purchase the batteries...? Congratulations again and thanks in advance! -Ian
Same Here!! Im just a sophomore (in college) but am trying to get some ideas on what i should do for my Senior project. (kinda get a head start)
Inksp0t6 years ago
I've been reading about old school hard tail minibikes lately. Many of those rebuilds use a torque converter (like the Comet TAV2) to increase the torque and top speed of small 3.5 to 6.5 horsepower horizontal shaft engines. I knew the goal here is to use electric, so my question is TAV2 or similar torque converter be used on the motorcycle conversion? I could be wrong but it seems to me that would increase battery life by decreasing load on the motor.... What are your thoughts?
Belt type torque converters are very lossy due to friction of the belt against the variable sheaves. Not advisable for use with an electric drive system. If you have a sufficiently powerful electric motor and plan your gear ratios such that the motor is running close to max RPM at the fastest speed you require, no gear ratio variation is required.