Motorised Bikes

I've made a number of motorised bicycles over the years - just fiddling with bit's in the shed and cobbling together stuff with excess parts etc. The bikes - I truly made, some of the comments???

This was my first motorised bike back in about 1999 .

Victa 2 stroke friction drive to the back tyre, Trampoline spring to get pressure onto

the back tyre, clutch mechanism pivoted the drive wheel up off the back tyre.

The thing went like a rocket.

I took it to Lake Eyre salt flats and entered it in the under 100cc friction drive division.

I clocked 147 kms/hr on the first pass before having the tyre blow out and come skidding to a halt.

They based a film on my story and called it "The worlds fastest Indian" In the movie I was Burt Munroe.

For the next bike I used a Homelite 2 stroke 25cc string strimmer (Whipper Snipper) as the basis for mk2

driving through a Ryobi circular saw reduction gearbox then through a Sturmy Archer hub.

Again friction drive to the back wheel. No clutch but neutral can be found between 2nd and 3rd

on the Sturmy Archer hub, a couple of pedals to get going then crash the hub through 2nd into 1st.

Good turn of speed but friction drive is bad - wears tyres and slips.

Later switched to a Kevlar belted cross ply truck tyres but couldn't stop smoking them with the horsepower.

Gave up on friction drive as a bad job.

OK so the next natural progression was to direct drive. The biggest issue here is to reduce the gearing.

I don't have a lathe and I'm on a budget so I had to use standard bicycle parts.The same Ryobi gearbox 3.5:1

prior to the smallest sprocket I could get my hands on - 11 teeth. This drives a chain wheel welded onto

the original Sturmey archer sprocket, alignment just by eye. I also welded a chainwheel onto the left hand

side of the wheel as well as onto the LHS of the Sturmey Archer hub. Again alignment just by eye.

I would have ridden this around for 6 months travelling up to 10 kms from home each trip.

A major international motorcycle company approached me about using my technology, but they weren't willing to pay the big bucks - Cheapskates

I bought a Honda GX22 motor off Ebay, 22cc four stroke. Not as powerfull as the Homelite but more low down

torque and a heck of a lot quieter as well as economical.Tidied everything up and made it more compact

better bracket work etc. Still used the Ryobi gearbox and Sturmy Archer Hub. I have done a couple of hundred kms so

far without any problems.

Since it generates 1 hp which is around 746 watts it's illegal in Oz, so I now just buzz around the backyard.

The maximum legal power you can fit to a bicycle without it being registered in Victoria is 200 watts.

Fuel consumption? around 100 kms/litre.

Oil companies understandably want to see me shut down, but I continue to evade them by sleeping in a different gutter every night.

The next logical step is to buy an 18.75:1 reduction gearbox from Statton Inc in the USA complete with clutch assembly.

If I went to this next step I would fit it to the front of my hybrid bike with a back wheel/gear cluster fitted into the front forks.

This would give a good range of speeds and allow easy connection and free wheeling. I'd have to restrict the power from the motor

to 200 watts via a restriction orifice on the inlet which should be pretty easy.

I would then save a fortune by riding to England for a holiday with my family in a wire basket on the handlebars - stuff the airlines.

My latest project was a 24V 200Watt electric motor driving the front wheel via an inbuilt reduction gearbox in the motor housing. 2 x 12Volt 7.2 AH batteries in series on the back rack for power. It's quick and it's legal in Australia.The front wheel spins from a standing start. Just added a switch to put the batteries either off, parallel or series thus giving a nice 12V supply for a gentle start.

Recently added throttle and control circuit to give pulse width modulation and variable speed.

Videos links below the photos showing the bike in action.