1947 excelsior EV project- from AUS

Hi everybody,

I've been trawling the ES forums for a while, enjoying the capabilities of all your works and builds.
I'm interested in building my own electric motorbike, stop buying fuel, save the planet, and have something cool to get to work with.

I have a frame: 1947 Excelsior autocycle. 8)
It has nothing on it yet, so look at it as a blank canvas with which to build a commuter that many may envy....

I would like to have the following capabilities, so please chime in with some examples, ideas and setups, and I'll be much appreciative .

Speed: up to 80km/h (~55mp/h)
Range: ~30km's (is this realistic?)
Budget: keep it south of $3500 :lol:
Charging: 220/240 Volt AUS standard. Daily charging if needed.

This project will primarily be to ride to work 10km's away, stop in at the shops on the way home, and plug it in for next day use.

I would like to use a hub motor if possible, because its simpler, but happy to see what options i have.
The less actual crazy detailed wiring and data board creation, the better. I'm smart, but not THAT smart.

Any questions, I'll gladly answer ASAP.

Thank you everyone for your help in this debacle. Haha

Looks do-able. Cromotor or similar hub motor- even search alibaba if you're feeling brave and they have plenty of 3kw+ hub motor choices laced into rims. Just starts to get trickier to find if you want to keep the pedals and chain- but I think Greentime sells one designed to screw a rear freewheel onto.

Lipo batteries will easily give you that range I'd image if you fill up the entire petrol tank area and maybe some of the area where the motor mounts.

Should be an interesting project. Keep us updated- and let us know what part of Aus you're in.

Thanks Spicerack.


I have a picture of the frame stripped and a set of forks I had laying about. I want to have a bobber/ cruiser kind of look to it.



Tape measure is for reference, 1metre.

My first idea was to connect 2x 36V-10Ah 'silverfish' batteries in series to give me 72V, make 2 sets of that, and parallel those bad boys to give me ~20Ah as well. They'll be around 30kg including brackets, etc, and bolt into the existing holes on the frame.
Step in and correct me at anytime people, this is all theory for a few weeks, while I iron creases out.


I'm lost on BMS's and the brains of this thing, but aesthetically, as long as it doesn't look like megatron poop, I'm happy.

Also, question time:
*** is it possible to wire these Silverfish batteries to have them all charge/activate/

Well an interesting project.

But have you thought at all about metal fatigue? Your asking 66 year old metal to suddenly be able to handle forces that it was never designed for even when new.

Take a look at some of the frame up builds that are being discussed here. Note that they are all starting with a much beefier frame which has been designed for its intended use as well as accepting contemporary parts.

Why spend upwards of $2k on parts only to end up with a finished product which is not up to the task? Its like building a house on a wobbly foundation.

Best of luck

Well an interesting project.

But have you thought at all about metal fatigue? Your asking 66 year old metal to suddenly be able to handle forces that it was never designed for even when new.

Take a look at some of the frame up builds that are being discussed here. Note that they are all starting with a much beefier frame which has been designed for its intended use as well as accepting contemporary parts.

Why spend upwards of $2k on parts only to end up with a finished product which is not up to the task? Its like building a house on a wobbly foundation.

Best of luck

Excellent point Kent.

My first impression of this frame was that the gussets and general heftiness of the whole thing would be adequate for ON ROAD use, as I intend to do zero bush whacking with the bike.
The old red oxide paint its been splattered with does it no favours in the looks dept.
Regardless of impression, I will definitely be taking it to the metallurgist at work and seeing what his Verdict will be.

Thank you for informing me, I definitely don't want to bust a weld at 80km/h!!