mini bike construction

[Sage]

Right so first off need to state I did fiddle with the search function and didn't yield anything helpful.

That aside I want to build a mini bike for burning man and for other events that I go to that will look like it was made by like goblin techies or maybe a bit of steampunk crossover. Heres a pic of sort of what I'm going for.
http://s272.photobucket.com/albums/jj18 ... cipede.jpg

Now ditch the wagon wheels and replace with larger thicker wheels from an ATV, make the handlebars and front fender be a bleached bull skull and made the entire chassis of the bike be a wine barrel and that's about my vision. I plan on having a steel frame for the thing but I am disguising that with a barrel built around the frame to hide the engine and also for ascetics.

I do know that by having an engine in an enclosed space I will need an intake and an outtake for the air and exhaust, but other then that what should I be thinking about? I really need something like schematics for gear ratios and drive chain construction and that sort of stuff. I really have never monkeyed around with moving parts before but am willing to learn.

So what can some experienced builders tell me about mini bikes that I should know?

[oneeyeddick]

If you don't have a liquid cooled motor, enclosing it inside a barrel is going to cause you some overheating problems, unless you attach a fan blowing directly onto the motor.

[LeChatNoir]

Hi Sage,

Gear ratios aren’t all that difficult. There’s a couple of things to remember and a couple of things to find out.

First you’ll need to know the rpm of your engine preferably at both idle and top speed (to figure your lowest and highest possible speeds). Then you’ll need to know the outside diameter of your drive wheel(s). Write these down when you figure each out. The things you’ll want to remember are formulas for figuring the ratios in sprockets and sheaves (aka pulleys).

In either case you will need to know the Pitch Diameters (PD). This is the median diameter of where your belt of chain rides. This information is available in industrial supply places or wherever you purchase or order your parts. It can also be found by doing a Google search.

Sheave/Pulley formula examples:

Let’s say you have sheave A with a PD of 4â€

[AntiM]

It has a motor? You will only be allowed to ride it if it is licensed as a mutant vehicle then. That's in the survival guide.

[Captain Goddammit]

What he (oneeyeddick) said was the first thing that grabbed me about the enclosed engine too. Air-cooled engines need a lot of air! Maybe you'd be OK if the barrel was open at the front and rear and you included an electric fan. I don't think it would hurt the look.

The second thing is if you want to use it at Burning Man, you have to keep the Dept. of Mutant Vehicles rules and regs in mind as you build it. Two wheelers are a difficult thing to pull off because of the 5-MPH speed limit. Good BM mutant vehicles need to be good at stopping a lot and crawling along slowly.

I admire anyone who wants to scratch-build something rather than decorate a golf cart.

[AntiM]

Oh, I very much admire the concept and the ambition, but I'd hate to see it impounded at the gate. Nasty little surprise that would be.

[LeChatNoir]

It has a motor? You will only be allowed to ride it if it is licensed as a mutant vehicle then. That's in the survival guide.

Yep Yep.

You'll have to gear that baby way down to keep it under the 5 mph speed limit. And the DMV will be triple tough on you with it likely being a one passenger Mutant Vehicle.

It'll probably have to be over the top of the top.

ETA: with that in mind, I say stick to the wagon-style wheels.

[ygmir]

IIRC, it also can't have a seat, you have to stand?...........

[Rice]

Sage,

Your project is pretty interesting!! If you could make it a 2 passenger vehicle it would be better...

You might want to check with the folks at DMV before you get too far along to make sure your are on the right path!

A DMV link from the BM page: http://www.burningman.com/on_the_playa/ ... s/dmv.html

Send them a email, see what happens.

Good luck!

Rice

[LeChatNoir]

IIRC, it also can't have a seat, you have to stand?...........

I believe that anything with a seat and a motor must have a Mutant Vehicle license. Anything with a motor that you stand on does not.

Those ring-dingy weedeater powered scooters kinda make me hope that changes.

[Sage]

I already was ready to get this thing looked at and hopefully licensed as a mutant vehicle for the burn and I have read that part of the survival guide on the speed limit and such. So does the thing need to be built so that it cannot achieve speeds over 5 mph or can I when at the burn build some sort of limiter on it so that I can't go over that speed?

As for engine overheating problems I like the idea about opening up the ends of the barrel to allow airflow but also could I construct some sort of grating or slitted ventilation to allow air in yet not reveal the guts of this thing while still getting enough air you think? Next up is where are some good online sites to buy some of the parts I will be looking for? I have been looking at motors a bit with craigslist and ebay but also I saw a small motor at harbor freight that I could easily buy from the store practically next door.
http://www.harborfreight.com/cpi/ctaf/d ... mber=66014
Thoughts?

Also there were thoughts on taking another barrel and making it into a sidecar that could be detached and then made into a pull behind as a cart for supplies.

[LeChatNoir]

Check your local tractor/farm supply store for loads of sprockets and couplings. Google MSC Industrial Supply Co.

Check with Encoas well. Their warehouse is in Fernley, oddly enough.

A fan is a good idea to move he air, I think. You could hook up an electric one to a battery. It won't take long for an air-cooled motor to overheat if there is not enough airflow.

I like the idea of a sidecar a lot too.

Speed limit is 5 mph. Most MV are based on automobiles that are capable of more than 5 mph, so I suspect no issue. a governor could be a good idea, though.

[LeChatNoir]

Oh… and here’s a great placefor go-cart type stuff

[Tiahaar]

Another great place for Bargain deals on surplus sprockets, pneumatics, hydraulics, motors, etc....

[Captain Goddammit]

Sage, so I get what we're brainstorming about, are you thinking of a normal two-wheeler that depends on centrifugal force in the wheels to balance, or something that is freestanding even at a standstill? Something that doesn't fall over at a stop is what you need on the playa, and your sidecar idea would be perfect to stabilize the thing. It would also make it more visually interesting (important for a playa-driving license) and haul more people (also important for getting a license).

If you haven't already gathered, mutant vehicle licenses are granted kinda' on a curve. The more people that will get to ride with you, the less the standard of awesomeness, the fewer people it carries, the higher the overall "wow" level is expected. So, yeah, that sidecar would be strategic in lotsa ways. And it's fun to bring company as you cruise.

If you had a fan in your barrel, I don't see why you couldn't put some wooden slats or louvers at the ends to conceal the mechanical workings. You'll definitely want your barrel to have easily removable sides for engine access, and the seams wont even show because of how barrels are made. I love the engine-in-a-barrel!
Car-type electric fans can be had ultra cheap at wrecking yards. Most are "puller" fans, mounted behind the radiator. If you want a "pusher" type, I've found that old Volvos contain great ones. Fans powerful enough to keep your motor cool draw a lot of power - you'll want a car-type alternator. That ought to be easy to drive off a belt from your motor.

Especially in recent years, another big thing to think about as you plan is impressive nighttime lighting effects. That's what the DMV expects in order to grant night-driving licenses. And - they haven't posted it anywhere yet, but on-playa there is a new reg requiring two red tail lights on all mutant vehicles. Enforcement is hit'n'miss, but just so you have the heads-up on that... make sure to hit that point. You also need a headlight, as well as the general overall cool-looking lighting.

The DMV has been known to be less than receptive to motorcycle-type vehicles, so make sure you cover all the bases to increase your odds of getting your sticker!

[LeChatNoir]

I was told on the playa in 08 that they’re starting to look for the same number of tail lights as there are headlights. I was only told this and have not yet seen it in writing.

Another great place for Bargain deals on surplus sprockets, pneumatics, hydraulics, motors, etc....

This is one of the big reasons why I love this place. Thanks, Tiahaar. Your link just found me a pulley that I’ll be needing for about $100 less than what I’d seen otherwise. That makes it that much easier to get to the playa this year!

[Tiahaar]

Most welcome LCN! Been following your Contraption thread raptly, what a wonderful diesel! Also Sage I agree with the Captain, go for the sidecar, low speed balancing would be a bitch otherwise on just two wheels.

[Elliot]

...bitch ... on ... two wheels.

Naw, handles fine.

[TomServo]

Oh, I very much admire the concept and the ambition, but I'd hate to see it impounded at the gate. Nasty little surprise that would be.

Is the bike pre registered? Know any daughter of a washoe county legislator? Looking at the attached pic, id pass it, if I were still with the DMV. Open the front of the barrel to cool the engine? And make sure it looks NOTHING like the base vehicle.