just my opinion.

deacon

minor bike philosopher
Jan 15, 2008
8,117
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north carolina
The differences between the 25cc WW mtb and the 33cc chainsaw bike are not great but noteworthy. Both will run faster than I care to go on the flat. So for me in reality there is no difference downhill or on the flat.

The difference comes in the hill climb. The 25cc bleeds off speed quickly and seems about ready to choke to a stop. There is obviously a pretty severe strain on the engine.

The 33cc chainsaw even with the wrong carb pulls much better. It bleeds off speed but not as dramatically and it even is pulling when the bike finished the hill. The speed is not increasing but it is obvious that the bike still has something left which is not always true of the 25cc.

My conclusion is that bigger is better some places but not necessarily much better most places. If I lived in a place with very very few hills, I would just as soon run the 25cc. In a place like where I live the 33cc is going to be better for errands but not necessarily to just putz around. Pedaling some is good for me I'm sure. I really don't mind as long as it is for short distances.

I think overall the 31cc WW is probably the easiest to build with and has enough pull for most things. I don't think i would build with a chainsaw again unless it was the 42cc just to see what it would do. However that said the chainsaw does have the two bearings so it might be longer lasting. Then again the engines are cheap on craig's list so why worry about longevity.
 

Jemma Hawtrey

New Member
Dec 29, 2007
288
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Essex, UK
I think alot of the hyper-powerful bikes are just unnecessary. Its not really required to have 120hp on any bike - 10hp is more than enough for most conditions and you end up getting to a point where the more weight the more power it drains off.

The Piped 32cc I ride is perfectly capable of most local hills and will stay in the powerband even on the longest hill I have currently experienced. I dont know what difference towing a trailer or loading up on racks and panniers would make - but I dont currently ride it like that so its not a problem.

If someone like GEBE made a frame mount two stroke kit using a commercial engine I think that would be the way to go - specially if the shifter kit could be used with it. Or a CVT....

Kudos for being able to make up mounts and such - thats alot beyond my abilities at the moment..

Jemma xx
 

jasonh

New Member
Jun 23, 2008
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Longmont, CO
I would venture to guess that a chainsaw motor would probably net you more torque than a weedwhacker motor.

Jemma, 10hp is more than enough even. The China motors put out like 2-3hp I think.
 

Jemma Hawtrey

New Member
Dec 29, 2007
288
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0
Essex, UK
I would venture to guess that a chainsaw motor would probably net you more torque than a weedwhacker motor.

Jemma, 10hp is more than enough even. The China motors put out like 2-3hp I think.
I wouldnt dare ride a 10hp cyclemotor - by 10hp I was talking about a machine with a full motorcycle frame. I have seen some of these 1500cc machines with 6 cylinder motors of 180hp - whats the point? I wouldnt even be able to get it off the stand without three people helping let alone ride it.

Although, I would love to have a go on that 4 wheel chrysler v-10 motorbike.

Jemma xx
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
3
0
north carolina
Well I'm at the point now where all I expect a bike or car to do is get me from a to b with a minimum amount of fuel, be the fuel gas or food energy. I think the 31cc bike is about the ultimate except. I would love to do a 40cc chainsaw to see how it would pull the hills around here.

It would be nothing to me on the flats. Even though I build for just my own needs, I would like to ride with my friends and neighbors. The 25cc is fine for that.
 

Ranger

New Member
Aug 7, 2008
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I hope that my 31cc comse out OK. I have found out by removing the flywheel and the cowling you can get to some really strong bolts.

I'm glad that I dont have any hills, unless you count a drive way lol.

Hope some of you have seen this, this site will sell you a kit or plans that will work for a variety of engines.
Conversion Kit 2
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
3
0
north carolina
If you dont have any hills to amount to anything a 31cc running full throttle should scare you to death. Mine does about twenty at half throttle on the flat and I think it is enough. I would guess that it would do 30 on the flat if you let it out and let it build a little.

I'm serious the bolens I had was scary.

I am going to drill some holes in the muffler of the chainsaw bike tomorrow and see if it picks up a little more umph on the hills. I do love these home made bikes. Makes me feel down right smart, even though my bikes are so simple anyone could do it.

Don't tell my wife but I bid on a 31cc ryobi on ebay. If I win it (I bid low so most likely won't) I'm going to probably put it on the grand daughter's bike so my son in law and I can ride again. I expect that the china bike is sold at least the guy kept telling me not to show it to anyone else and he is a neighbor. Probably never see him again.