chain saw 2 the sequel

deacon · #1 09-04-2008, 02:45 PM

The 42cc chainsaw engine arrived today. It starts so I'm going to put it on the full suspension bicycle from my grand daughter. I just wanted to take the day off and rest up.

I did put a front hand brake back on the full suspension. I refitted it with a 20" rear coaster wheel and tire. Probably going to need a new tire the one on it is a knobby. Those do terrible. Beat the motor to death I think.

deacon · #2 09-04-2008, 03:46 PM

I bought 2 new 20" road thread tires for the chainsaw bikes. The wheel on the new one has a knobby and they are pretty rough on engines. One of these days I might just take a sander to all those knobbies I have laying about.

I also need to find something to do with all those 20" front wheels I have laying around. If I built a 20 scooter with no pedals, I could use them on the front and back. That's kind of an interesting thought. If the pedals were gone I could use that 20" bike I just bought and removed the engine from.

Hand brake to stop it, push off to start it moving. Wouldn't be real good around here but in an area with few hills it might do well.

deacon · #3 09-05-2008, 02:24 PM

just so you know I got the 42cc stripped and the mount attached. Tomorrow I will try to get the drive wheel welded up. (thanks shoes I'm going to have yours welded to the clutch nut. That is if my man will do it. It looks like rain so I think I'm just going to leave it with him. I can do almost all the rest of the stuff.

I had to use a pry bar and sledge hammer to break that rusty old clutch nut loose.

tomorrow I need to change the knobby tire for a road tire, mount the engine on the bike, and wire the controls. Well at least I'm going to be doing some of it and rethinking some of it.

**Dan** · #4 09-05-2008, 10:58 PM

Awesome Deacon. Today I was telling some folks about your altruistic efforts to bring ultra-light, inexpensive transportation to the masses. I described it as the "VolksBike" snork. But your efforts are truly a gift. The folks who I was talking said they wanted your book and I told them to look on eBay.

I am a student in the fire academy and not making much cash until Jan but am planing to try a build with a chainsaw. The whole drive train, engine, CVT and roller will be on a slab that pivots under the seat. Up and horizontal, the roller is engaged with the rear tire. When the clutch handle is pulled, it lifts the roller up and points the engine down towards the crank shaft. Muffling will be a big problem. But I am going to experiment with running exhaust out of a large diameter radiator hose. gives it a great "thump, thump" sound. I just don't know if it is a fire hasard. (lol, said the future fire fighter)

deacon · #5 09-05-2008, 11:38 PM

I used to hang electric motors there. The problem was that to hang them over the side and line them up they had to be in the way of the pedals and god knows with those motors one had to pedal.

I rebuilt the mtb with a 31cc ryobi using only the techniques in the book and it runs like a scalded dog. That little design is the way to go for a cheap motor bike. the motor was twenty bucks on ebay... the bike was six bucks at a yard sale...hardware was way too much but thats what I had to do. It still came in under a hundred dollars for everything.

Shoes has the same motor and will tell you that the engine does a decent job of moving people from a to b. Maybe not in the rocky mountains but at least in most places.

The accomplished biker can ride a bike at about ten miles an hour. On the pure flat these things will do about 15 to 18 I think. On a downhill they will do over twenty easy. Going up a steep hill you might fall down to what a biker could do, but the effort is much much less.

I heard it described as like a tandem bike where the other guy actually pedals all the time.

**Dan** · #6 09-05-2008, 11:52 PM

"...a tandem bike where the other guy actually pedals all the time."

Snork, snork. thats good. "Roll you'r own bikes" would be a great name for bike motor company!

**Dan** · #7 09-06-2008, 12:23 AM

With removing the pull start, I think a 2stroker saw motor will make the magic 5 inches and be peddelible, peddling. No Deacon? Is hard to get an accurate measurement in a store with the cover and pull start. My goal is to come up with an easily mass produced, easy to install and marketable kit and offer a real competitor to the HT. And a high end one as well.

deacon · #8 09-06-2008, 06:57 AM

there is a need for a kit that is easier to install than either my directions or the china bike.

People will actually pay a premium for an 'out of the box' bolt on kit. A good friction drive about 40cc would fill the bill. As long as it is easy start and has a clutch of some kind.

A clutch because you pedal it with no resistance for starting. My bikes would all start with the pedals except I like to warm them up while they are sitting still.

But the kit should be one piece with a few simple bolts to tighten, fill it up with gas and ride away. If you can do that for 200 or even 299 I think you would have something. With a good marketing plan you should make a killing. I would start the marketing in Fla. and California where the buyer can ride them year round. Then move to the cooler climates. I wouldn't even bother marketing in the mountain states.

The big advantage to the out of the box kit would be no need for skills. The china bike kits and even the four stroke kits are limited by the fact that some mechanical skills are required. If you had a kit that a hockey mom could bolt on then you have one that guys like me would buy. An add on QVC with hockey mom bolting it onto her mountain bike and you would be an instant success.

I did like the looks of the zip bike I saw on here. It is a inside the frame mount. I think the problem would be the need to jack shaft it to bring the drive in line with the rear wheel while still keeping the engine inside the frame.

The biggest downside to the bike with the front mount engine is the 'sitting balance'. When the bike is in motion it is a non issue, but sitting still and when you are pull starting it. the bike is horribly off balance. But the bike more than makes up for it in ease of building and (I believe) better pulling of the engine.

But you really need to keep the weight down. The chainsaw was too much. The larges weed whacker is about all you can do. I have a bigger gas tank on mine since the little weed whacker tank doesn't look as though it would be enough. I would like to have enough fuel on board for a twenty mile trip. If a person is commuting more than say ten miles each way, they really are going to be uncomfortable on a bike. I know some people do it, but I'm talking about most people.

**Dan** · #9 09-06-2008, 07:25 AM

You are absolutely right. I do believe the market for ultra-light transportation that can fit on the bike rack on a bus or be carried in to an urban dwelling would sell well. My original thought was to market to law enforcement, campus security, EMTs etc. So I bought he name code4bikes.com. (cop speak for "no further assistance needed) I really don't try very hard selling HTs. but keep the page anyway. I think the real growth potential is in the cities. Is a good time all around for marketing a bicycle with motor assistance. The more I look at the weed wacker, the more I like the concept. It has the potential to be a simple mass produce and is upgradable with the addition of torque conversion. I have trouble appreciating them due to the esthetics though. Trying to sleep this morning, (on third day of manic and had a fire call. so no sleep *&^%$#^R) I thought of just adding a compartment on the other side about the same size as the motor just for the looks.
Scooter sales went up 23% this year mostly in the urban market. I sold 3 bikes wile having coffee at a gas station when gas went to 4$. Time is ripe. Any one in New england went in? I would say "lol" but I am serious as a car door opening to the right when doing 30 MPH.

deacon, will a 40 or 50cc saw motor be less the the magic 5" with the pull start gone?

deacon · #10 09-06-2008, 10:11 AM

Well I'm going to keep my pull start on the chainsaw bike till it breaks then it is gone. It will rope start just fine I know that much. The drag shouldn't be too bad. I found out from the new bolins 33cc I bought that is it more about compression and tension to drag start one than engine size. The used 33cc chain saw drag starts very easily. The compression is down. Anytime I increase the tension it helps to start the engine.

A friction engine will slip and you want it to slip some so the wheel can turn faster than the engine would turn it. But you do need enough tension to get a good turning rate to start the bike. For me it's just trial and error.

After I get the used 42cc on the bike I'll let you know if there is any problem drag starting that, but a new one I don't know. It would seem the 60cc china bike engines drag start but they do have the chain thing going for them. One other thing I never drag start a friction drive of mine cold. I rope start them first to warm them up. That way I have the maximum starting odds when I do drop the engine. That is something I can't do with my china bike.