Rokon 2 Wheel Drive Type Vehicle

[uncrichie]

Anyone familiar with the Rokon 2 wheel drive bike/scooter type off road vehicle? Wondering if anyone here has tried to build something similar? Or knows of a sight where someone might have such an article on building. Tried Google but they just have info on Rokons and the old Arctic Cat models from yesteryear. TIA. Uncrichie.

[Hotfoot]

I know the machine, but will be of no help in finding or replicating one. I had a Rokon 340(??) or something like that... had a Bombardier Snowmobile engine. Pretty fast dirt bike, but used too much gas for enduros and Hare Scrambles. It had constant variable belt primary. Very clunky by todays, standards.

the model you are interested in was the "Trailbreaker".. Google Images "Rokon 2 Wheel", and there are hundreds of photos, many of which will come from sites you are looking for!

[usmcpop]

Well, there's the rear-wheel-drive Rokon 340 variable-pulley transmission MX bike

http://dirtbike.off-road.com/dirtbike/article/articleDetail.jsp?id=332644

Which, incidentally, is listed as one of the 10 worst dirt bikes here: http://dirtbike.off-road.com/dirtbik....jsp?id=265930

(HF, I really wanted one at the time...)

and there's the 2-wheel-drive Rokon Trail Breaker (tractor). http://www.rokonworld.com/history.html

I also note that the Suzuki TM-400R is listed as one of the worst MX bikes, due to its beastly and erratic power (and little flywheel). I used to work with a guy who loved it, but he always said if you don't crash at least a few times whenever you practice, you aren't going fast enough. When it was brand new, he managed to loosen all the spokes in one weekend's ride. He was one crazy guy.

[uncrichie]

The Trailbreaker (tractor style) 2 wheel drive is the animal I'm referring to. Its slow by any standard 20-25 mph but will climb 60 degrees. Its low gearing and wide underinflated tractor tires really do the job. A single rear wheel drive would be very easy for me to replicate. Its the drive to the front wheel thats the challenge. I have seen some hydraulic motors that are capable but alittle pricey and I'm not technically versed to be able to design such a system. I think the older model used some type of a sliding coupler over a toothed shaft to get power to the front geared jackshaft. I can't really explain it but it was simplistic and noisy from what I've read. Anyway that is the beast that I'm interested in constructing. By the way it has no suspension, the comfort or discomfort of the ride is determined by the air pressure in the tires. Something like 3-5 psi. Uncrichie.
Edit, I could always mount a smaller engine over the front wheel with an auto clutch to take up the slack. Alittle cumbersome and more noise.

[usmcpop]

Though some things have changed a bit, check out the old patent drawings here:

http://www.google.com/patents?id=BwpUAAAAEBAJ&pg=PA1&dq=Charles+Fehn#PPA3,M1

[uncrichie]

Thats really neat! Thanks USMCPOP. Uncrichie.

[grayw0lf]

If you come up with some good Rokon-type plans, please share!

[Hotfoot]

They're selling them new here...

http://jandowning0.tripod.com/id1.html

I just Googled "Roken Trailblazer"...

[calweld]

Factory website .... and they'll ship direct!

http://www.rokon.com/

[uncrichie]

I'm deliberately trying to avoid $5K. I'm gathering parts (very sporadically) to build something similar. The expense is in the wheels/tires and front drive unit. But still I'm missing something or there is a tremendous markup to the Rokon? More than likely because its the only game in town. With ALOT of home brewing and machining and scrounging a simplistic design can be built alot cheaper but not better? I plan on using a torque converter and extremely low gearing. I won't need any speed. Only looking for a top end of 10-12 MPH. I prefer to do sightseeing mostly. If I look at something too long and hit a stump or tree, crawling speed should keep me from serious damage! I believe the Rokons have a transmission with 3 speeds. Thats nice to have when you hit a large clearing or trail but not for what I need. I'm really looking for a mechanical replacement to a mule. Its going to take awhile as I have (like most) numerous projects in the workings at any time. When I get tired of one I move on and then come back again with renewed interest. I find this to be a blessing in disguise as I mentally over time comeup with multiple design changes and thankful I didn't build the first edition. Thats it from here, just gathering parts. Thanks to all who are keeping this thread alive.

One example of my scrounging. I'm planing on using front wheels and tires from a wrecked tractor. I'll have to design, build and weld the hubs but this shouldn't be a problem. Remember this one will be built for crawling speed I won't be building to NASA specs and tolerences!
Uncrichie.

[calweld]

I understand, I was just posting for general information. Before you started this thread, I had no idea such things even existed, let alone were still available today. Spent a little time this morning educating myself on the interweb ...

[uncrichie]

Hi Calweld, they are pretty neat machines aren't they. Thanks for posting. They have tremendous pulling power and with tractor tread tires underinflated they can go just about anywhere. If I had the $ I would buy a Rokon right now. I really enjoy hombrewing though, sometimes I think the journey of the build is as much or maybe more fun than the finished product.

FYI, arctic cat the maker of snowmobiles once designed and manufactured a similar 2 wheeled vehicle which occassionaly appear on e-bay as do Rokons. I think the Arctic cats disappeared in the early 70's?

I remember as a kid I would see all types of similar "you build at home" vehicles in popular mechanics magazine, early 60's, ouch I'm gettin old! Uncrichie.

[stevinator]

Uncrichie if you haven't already go to vintage projects.com.I saw an off road bike on there with low gearing and big tires.It's in the mini bike or off road section. The plans can give you some ideas,I thought the one on there would be neat to build but they don't use a modern torque converter drive.Different things would have to be modernized.If you start one keep us informed I like stuff like that.

[uncrichie]

Stevinator, thanks for the website. You won't believe this but I purchased the exact article from e-bay. It was an article from an old popular mechanics magazine from the 60's. It was only a couple bucks for the original pages from the mag.

Its a nice read. very simple frame and drive assembly. It gives the option of low gearing through the pulley system for off road or on road use. I may use a similar design if not the torque converter. I'm leaning more to a slightly narrower tire with a tractor tread design and slightly larger in diameter for alittle more ground clearance (actual tractor front tires). All in all it appears to be a good design start for this type of bike.

I'm still in the parts collecting stage but will post when the start begins. When I was a kid I saw others that had neat stuff like this. I didn't have the knowhow or the $ at the time. I think I'm reliving my youth when I tackle these projects.

I'll post when the project begins. Uncrichie.

[mudbug]

Go to http://www.hydraulicinnovations.com/ Jeff just built one and if you link to the forum another member designed and built one too. They are a helpful bunch and don't mind sharing. It may shock you... They are hydrostatic drive,but work great. Enjoy!