Bicycle powered by. . .a chainsaw?
 

Alright, this is odd.

I happened to be repairing one of the chainsaws( I live in the woods so cutting up dead trees and burning them as firewood is cheap heating(Its a complicated wood burning system not just a straight up fireplace because that sucks air in from outside, I know)).

I noticed that the drive on the chainsaw happens to mate almost exactly with the chain on my road bike. This got me thinking, since I only really need one of the chainsaws(No one ever helps out lol) and since the weather is pretty nice. . .

How do we feel about powering a bicycle solely by a chainsaw?

The roadbike is very light and I'm pretty confident I can switch out the assembly with not alot of effort if I just want the bike back. Its a 4-5ish horsepower chainsaw(its a little older and I suspect the compression ring isn't all there, but it still works fine to chop stuff up.

Fuel consumption at full tilt is substantially less than a gallon per hour(as much as I can estimate it uses about a half gallon for an hour WOT). Obviously on a total weight of less than 200 lbs(me and the bike) I'm not going to need WOT for my morning commute. I'll need WOT uphills, and thats about it.

This is a goof off project that I am only likely to spend about an hour. As of now all I would have to do is move the throttle control to the handle and mount it.

2 stroke mopeds usually have much smaller engines, but still produce far more pollution than cars.

I have actually seen a bicycle powered by a chainsaw engine. It was converted to run on propane as well. However, it only went about as fast as a normal bicycle due to poor gearing.

No way.

This road bike is pretty old and I've never seen or heard of the brand anywhere else lol.

I slipped the chain over the teeth (bike chain) and it fit. . .but I can see it being a problem under load(slipping) So I'll have to do a little of something.

I'm thinking drop the plate from the chain saw and use the gears from the bike. . .?

I think without using a jackshaft your RPMs will be way to low to power from the chain. I would look at using a small friction wheel on the clutch up against the rear tire. I think the gearing would work out better.

Emissions
I had heard that Husqvarna (sp) was using a spark arrester screen coated with catylitic converter metals to greatly reduce 2 stroke engine emissions.

Don

Yeah I had thought about this a little. The saw has trouble at low speeds unless you gun it to high rpm and then it can slowly coast down to lower than you can hold and cut. . .but I'm not at all certain if thats more a function of the blade or the engine.

Both are much less effective at low RPM I know for sure, but I can't help but wonder if the saw would be able to pull it out from a stop. Acceleration won't really be an issue(unless it won't) so I guess I'll just have to test it out first?

I have a Stihl that I wanted to put on a bike once upon a time.

Since then I've decided that a four-stroker would be much better- preferably Honda 50cc

I would prefer a four stroke as well. . .but I don't think I can find a four stroke for about 30 bucks. Fleabay has working 50+cc chainsaws going for about 30 bucks plus shipping.

If they actually work or not. . .I dunno. . .

Tire drive is extremely simple though does have some problems.

Otherwise, first up your front and rear sprockets will need to be determined. HP you give at 4-5hp.... so its a big saw?

Most scooters have around 3 HP which allows 65km/hr on a 80kg machine with tons of drive gear drag.... so a 5hp bicycle will be a rocket. Your cycle chain would be too small and snap unless you grannyied it.

Try a 29cc off a weedwacker. Cheap as chips, even new and super light. Buy with a warranty. I have a Honda 4 stroke weed wacker- perfect!.

A MTB disk brake cycle rear disk can be removed from rear hub, modified to install a very large/but light belt pulley with a tiny belt pulley(alloy) on the wacker motor shaft. Or you could cable tie a big pulley to the spokes???Attach to the rim???

Ideally mounting the drive train in such a way that the bike could be used just pedaling with motor disengaged. Another ideal feature would be being able to bump start, rather than get off and pull start.

Pulse and glide should be designed in..... especially considering its a cycle as pushing and pedaling can move the vehicle as well.

Hypermiled with even an inefficient 2 stroke wacker motor, FE with PulseGlide could be as high as 500mpg....maybe 2000mpg depending on how much you want to pedal.

One way to engage and disengage the motor could be like a handbrake type lever mounted on the cycle top tube operating a cable, actuating a cam that moves the motor away from the rear axle thus tightening the rear belt and engaging the motor.

Early mopeds drove the tyre with a nolathane/rubber/urethane bush on the engine shaft. These bushes typically lasted around 1000km and required special tyres that wore too I believe. However, tire drive has potential, especially if a tyre was made with a ring gear incorporated into the sidewall. Personally I like the idea of disk brake hubs on MTB's to secure large pulleys with the handbrake type engagement. The early Velocycles's were difficult to pedal and heavy.

This area is ripe for redesign and innovation, as the plethora of electric hub motor bicycles would suggest. Rocketing down the road at 45mph on a cycle with ordinary frame strength, braking and handling may require life insurance.

What ever happened to Tidalfoce?

IO Tidal Force Electric Bikes by Wavecrest

Rim drive....axle less wheels.....aerofront cycles.....sails.....wings....liftoff....big leg muscles

I have been considering the issues at hand. . .and they are many. . . but I'm still going to go forward.

Yeah I decided on a different chain(tractor accessory chain ^_^ got it from the shop). The teeth on the bike are about right so maybe a little tweaking and I'll be ok there.

Bump start should be easy to implement. Sorry folks I'm not a hypermiler, The pedals will be coming off and going for stationary(solid) pegs.

The 5hp from the chainsaw. . .its a homelite x12 and I think its either 54 or 56 cc(normal scooters are under 50cc usually), will likely put me in range of truly terrifying speeds on just a bicycle.

I've ridden motorcycles. . .but they feel a little more protected at highway speeds while bicycles feel very uncomfortable at near highway speeds lol.

Pulse and glide would be very rough in the motor for this application(bump starting every time on such a small displacement engine). I think I'll be content with 130-150s.

I would have started and finished the project. . .but a friend had a clutch blow out so I had to drive over and start the replacement process. Just a few more bolts to get access to the clutch and then I have to put it back together. Probably sunday before I get time to do anything -_-. . .

It's officially too large of an engine to qualify as a scooter. . .but I think I can pop the name plate off and avoid any serious questions.

Maybe better yet: I've seen rechargable electric weed whackers at Home Depot. Mount a sprocket, and there's your electric bike.

I have a BikeBug aux bike motor with the friction wheel drive. It works but it's sensitive to tire pressure and proper adjustment. And it'll spin out if the tire gets muddy. I think there is a better way. Oh, and it's 22cc, 1.2 HP- it's enough.

You don't "tweak" chains and sprockets! :rolleyes: Either they are made for each other and they fit, or not.

I know you can't change anything on the chain, but I have yet to compare it with the chain saw teeth(I know it won't fit). So I'll need to tweak the chainsaw to get that to work, and by tweak I mean find a new sprocket.

I'm seriously considering(since the chain I've got pretty closely fits the bike(if its not dead straight close enough I'll just go get the sprockets that are on teh tractor it goes with)) just using the bike's rear assembly. It allows the chain to spin free of the wheel if you aren't applying load and I am pretty sure it could survive the chainsaw as its going to be a much more steady loading rather than the pulse/cyclic loading that we perform pedaling.

James I thought about using the electric ones but the battery life was pretty short of the ones I saw at THD. I think it was about 15 minutes and that won't even get me to anywhere lol let alone there and back. I do have a few spare drill batteries(from non-functioning drills that don't mate up to the new counterparts) but. . .

If the project works out well I may go electric on MKII, which will be my test-bed for CF fabrication and I can build in battery mounts(and engine mounts for that matter) as well as have a lighter platform for the motor.

Now there's an idea! There are plenty of tired mopeds sitting around. The motor is legal size and surly pulls the weight. Rebuild one and you wont have to worry about whether or not your weed eater is going to pull you. I'm 300 lbs my self and have read about weed eaters are best for teens or under 150 lbs adults.

Either way... I like the pusher trailer design using a small cart wheel on the ground. This keeps the bike legal with peddles and such, plus you can create a quick disconnect and a swing up or rack system for leg power mode (out of gas lol).

Take a look at the expensive but totally cool product Ride Kick

Now think of a small gas motor driving it. Use a fairly good size rock to hold traction. When you break down or run out of gas and have to go leg power, drop the rock off to live with other rock friends; Set it free! lol Then walk or peddle the bike home with just the weight of the motor and rack.

If you peddle the bike then you will be walking for sure.

You could go FWD:
http://i1090.photobucket.com/albums/...ainsawbike.jpg

Or Go extreme:
http://i1090.photobucket.com/albums/...motorcycle.jpg

I do like the idea of the saw coming off the front- this is essential to a chainsaw powered cycle. Tell those pedestrians to GTFO of the way!

The rear mounted engine driving the cassette sounds like the best solution. You could even add a chain tensioner to the down tube.

Here's some not-so-crazy 2-stroke motorized bicycle eye candy for you...

http://www.sportsmanflyer.com/IMAGES/racer5.jpg

You can check out his bike and lots of his other masterpieces at Sportsman Flyer.

I had a 4 stroke bike motor... loved it. Sold it when I ecomodded my commute down to 2 miles from 25 miles (yes, moving close to work was deliberate and the BEST DECISION EVER)

This is my review - Cool Tools: Golden Eagle Bike Engine

Well you are thinking absolutely stunning of adjoining the bicycle with chainsaw, great idea.

Leave the poor dead horse alone! :turtle:

First read the DMV laws for your state and locality. I have a chainsaw based motor kit from the 1980s that is friction drive. It is legal in PA but not NYS The engine is a 34 cc 2 stroke design that was bought up by Poulan. It was rear mounted but front mounts engage better. Bicycle chain is 1/2" pitch so if the clutch works, use it. Gearing is the issue. An engine may turn 5000 to 7000 rpm but the wheel only 200-300 rpm at 20 - 30 mph. Do the math for your components. A jack shaft reduction system may be needed. A motorcycle throttle and a kill switch are needed. Make sure the tires and brakes are in top condition. An air filter for the exhaust will reduce the smoke and noise. The newer the engine the better the emissions reduction. A good frame mounted fairing and tail box will cut drag. If designed right the engine heat can be directed away in the summer and used for heat in the winter. A small fire extinguisher might come in handy, just in case.

FWIW You can buy Wizzer kits on Ali-Express. Fairly well priced and all the parts included, an old schwinn or a 10Speed is a good candidate..

I love how this thread was brought back from the dead by someone with only one post. A shelf account?