chain saw 2 the sequel

deacon

minor bike philosopher
Jan 15, 2008
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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

minor bike philosopher
Jan 15, 2008
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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

minor bike philosopher
Jan 15, 2008
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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

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May 25, 2008
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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

minor bike philosopher
Jan 15, 2008
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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

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"...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

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May 25, 2008
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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

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Jan 15, 2008
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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.
 
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Dan

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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

minor bike philosopher
Jan 15, 2008
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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.
 
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deacon

minor bike philosopher
Jan 15, 2008
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north carolina
I got the drive wheel back and got it on the engine. I turned it over with the plug in and the engine has low compression. I suppose it is why it was so cheap, but then again I guess I can stick a ring in it to see how that does. If it's like my poulan the four bolts in the bottom of the case holds the jug on. Take those out and the jug comes right off.

I removed them by mistake on the poulan and wound up with the piston in my lap. I am going to run it first then take a look at a ring for it.
 

deacon

minor bike philosopher
Jan 15, 2008
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Today was a waste. I started out with the clutch to rig and the hinges to make. Okay I did get the hinges made. I also redid a few things on the mount but the clutch never did workout for me.

I was going to use the fence rod like I had seen done bye someone else here. I must have done something wrong cause mine broke when I put pressure on it. It broke at the drill hole. I didn't have another piece of metal long enough so i began sticking things together and trying them.

It was one step forward and one back. It left me petty much where I was last night. I think I have the design mastered.

Now Shoes uses cables and pulleys. Obviously smarter than me. I use your time tested lever and fulcrum method. I figure it if was good enough for the ancient world it is good enough for me.

I think I have it figured out but I needed about a foot more lever. I have already pieced together two feet but I found a seat post insert laying about. It will make the final foot just fine I think.

Since I am going to have some extra time tomorrow, I'm going to redo my scissor henge on the motor side. It has too many parts now. I want to just have two pieces. I have enough of the fence bar to do that I'm sure.

Then of course it is going to set in to rain for a few days. I'm not in that big a hurry to ride the 42cc full suspension bike. And If you believe that, I can get you heavy date with the tooth fairy for a reasonable price.
 

deacon

minor bike philosopher
Jan 15, 2008
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I forgot to measure it today but I will try to remember tomorrow. I think it would be very hard to work with a chainsaw for that. You can strip off all the crap they put on to make them purdy. I had to grind the plastic down to get a squarish package. That meant a seperate gas tank.

the luggage rack on the other side of a rear mount engine is a good idea actually. But pound for pound the WW is the way to go. I wanted to try this 42cc and will let you know how it does but I love the WW front wheel drive. Even with a smooth drive wheel it does pretty darn well. The smooth wheel does very little damage to a tire. The grinder type pegs may do a lot more than I would like.

I have a grinder for my chainsaw but I also have a 1 1/2 inch smooth wheel in reserve. I'm going for ultimate machine first with the 42 cc then it will be what makes the most sense for me.
 

deacon

minor bike philosopher
Jan 15, 2008
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file under learn something new every day.

When you sit your fat butt on a full suspension bike, all the cables change. the reason is that The distance between the back wheel and the handlebars changes as well. It's gonna be interesting to see what I can do with this thing. I should just rip the chainsaw off and put move the front wheel drive to it.

But alas in for a penny ect.

Lesson one///I am going to a pure suicide clutch I think. I have never had much luck with the suicide only so this will be interesting. It is also going to effect the throttle cable but I don't now how just yet. I'll probably have to sit backwards on the bike to adjust the throttle cable. Fortunately I won't have to ride it facing backwards at least I hope not.

Lesson two/// before you curse your chainsaw motor for not starting try the rope starter rather than the recoil starter. I have no idea why but I cranked my guts out off and on all day and nothing. In desperation I wrapped my rope on it an it fired right up. tomorrow the recoil starter goes in the trash.
 
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deacon

minor bike philosopher
Jan 15, 2008
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north carolina
Much as I hated to do it, I went to a cable system for the gravity clutch. No it wasn't the first time but it is the first time I had to make my own lever system. The brake lever just doesn't have enough pull so I had to drill a hole in the bike frame. I didn't want to do that but this bike has a huge frame so it should be okay.

I still have to figure a way to lock the cable throw down. Something really simple would be nice. Maybe just a bump on the bike frame would do it.
Anyway here are some shots just in case anyone is struggling with the same problem.


 

deacon

minor bike philosopher
Jan 15, 2008
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Well all systems are in place. All I need now is good weather to try it out. I have the gravity clutch lever wedge in place. It was a lot easier than I thought to make the lock. I just drilled a hole and screwed in one of the machine screws from a weed whacker. If it works loose, I will just epoxy it into place but it seems tight right now. Best of all it appears to work.

The chainsaw engine got a remount yesterday while I was waiting for the rain to stop so it is more secure today. Everything looks good for the test run whenever the weather cooperates.

I don't want to take off on an untested bike when the sky is cloudy. It has rained off and on all day the last couple of days. Even when the road gets dry it still looks threatening and is likely to rain any moment. If I get stuck a mile from home, I prefer the warm dry weather.

I also need to ride the mtb 31 since the carb still is shaky. I think it just needs to be ridden it might even be the homemade gas tank. So many little projects.

As often as I post things here I probably should just start the "Diary of a Mad DIY Builder" lol
 
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Dan

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May 25, 2008
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Deacon, do you have any pics of the chainsaw build up any where? I am looking forward to seeing how you did it. (Just got an offer of one to be donated)

The full suspension looks awesome
 

deacon

minor bike philosopher
Jan 15, 2008
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No but I'll give you all the information I have...

Take the engine if it runs you will have a good bike engine. I love my 33cc now that it is done. I think they are a little beefier than the weed whacker. They are just a little more trouble to mount but not much more.

To mount them you just do pretty much the same as for the front mount but you have to do it on the back wheel. It is too heavy for the front wheel.

The main difference is in how you attach it to the mount and the controls.

What I do is to turn the angle iron backwards so the engine sits on angle not hangs on it. The bottom of my case was plastic, so I drilled some holes and used the screws from the case and some I had laying around from the weed whackers to hold it down to the angle iron.

Just bolt the angle iron to the hinge and you can use it just like the front mount. You really need the scissor hinge to keep the engine from wandering around. If you need pictures of how the thing is mounted let me know and I'll post you some. I don't have a set of detailed build instructions since I didn't think it would fit into my easy to build scenario.

There is very little difference in the mounting of it in reality. Let me test out this new gravity clutch setup and I'll let you know if it works okay. If it does it is the way to go.

Oh yeah, I had to trim my case down some to make it a rectangular box. They had all these cute design features. I also had to make an exterior tank because I drilled into the one on the saw to attach it to the frame. My tank holds more anyway.

Saddletramp said you could buy a child's plastic canteen at wallymart and that would make a good gas tank. I bought a bunch of them cheap so it is what I used on a couple of builds. I got mine on ebay.

The full suspension is a pain but it looks like it is going to work out okay. When I plop my butt on it all the controls change. The rear goes up to absorb my weight and that makes all the controls slack. It probably won't be insurmountable since the clutch is now on the frame not the handlebars and the shifter I use as a throttle has a lot of throw so it should take up any slack. Still need to ride it to make the final adjustments.
 
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Dan

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May 25, 2008
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Deacon, dunno why this just crossed my mind, but you should teach this at a local community college. "Ultra-light transportation, 101. A DIY builder's guide"

Would we have to call you "Professor Deacon" then?