160cc Victa mower engined Bike

[Pezz]

I have posted in the welcome forum. Here is my 1st post outside

I have been riding motorcycles for about 25 years and do lots of travelling.

Have a group of friends who meet regularly. decided to have a scrapheap challenge. Rules are quite simple.
The Challenge
Get a Pushbike and fit an engine . . .
It must complete 10 laps around a track set up on a mates 40 acre Property near Parkes in Australia.
It will have a Sand trap, water hazzard, ploughed paddock.
Must be completed by the end of the 2008
We will also include a hill climb event as well.

Rules
You must:
1. It must be cheap . . . $200 limit and you must document the build.
2. Can use any engine that you are game for.
3. Start with a pushbike frame
4. Use pushbike wheels
5. Have working brakes Front & Rear.
6. Use the front and rear sprockets of the bellcrank, but can remove pedals.
7. Use the pushbike chain. It must be fitted but you can use another for drive
8. Send pic of frame before you start.
9. You can invite friends to be involved. The more the merrier.
10. Hopefully with video the carnage.

So Far I have a Victa 160cc 2 stroke engine and picked up an old mountain bike and a set of Manatou 80mm forks for the front.

I have worked out the swing arm design with a motorcycle rear shock. Where the motor will mount. I am going to run an expansion chamber and M/C carbie.
As the rules state, I need to use the bicycle chain and drive. So I will position the motor on the RHS and run the reduction drive in the LHS.

I just need to work out how I gear the motor down from 5000RPM to 26" wheels at 80kph (45MPH) Belts of chain & gear reduction?

I will attach pictures as it develops.

meanwhile here is a Victa 160cc 2 stroke in a BMX frame.
http://www.youtube.com/watch?v=GDQTKdcZbzQ

Pezz

 

[Pezz]

Okay been doing some reading.

Gleaning some info off an electric bike thread & here http://www.peltzer.net/ebike/

To gear for 75kph I need 625 RPM of the rear wheel. I basically need an 8:1 reduction. I am thinking I will do that with a reduction gear in 2 stages 4:1 then another 4:1 to the bell crank and a 1:1 to the rear wheel. Was thinking belt would be easier but a lot more work to get right. I am thinking chain reduction

 

[fastboy9]

Sounds like a great idea! I moved the thread because it was in the wrong place. look forward too hearing more about this, looks like a great idea! The video of that BMX looks brilliant, 160cc is going to be crazy!

 

[ducatiluke]

http://www.youtube.com/watch?v=9C9JY5klARE

go 4 stroke briggs and stratton 148cc

 

[Pezz]

Thanks for the link

I have a few constraints, namely $200 limit.
I also have the 160 Victa which I was given by one of my competitors.

Bang for buck it will be pretty hard to beat. It is also easier to be able to turn the motor 90% and have the shaft on the horizontal

So far I have only spent $26.00 for the Manitou 80mm Forks. I have the frame, engine and shock for the rear.

I am looking at a 1979 CR125 exhaust pipe and might see if I can get it on there too