Hello! Compass without a needle here!

[oliveclown]

Awesome site! I thought I'd be the only person who would ever think of motorizing a bike. Shoot, I don't think there would be a whole following. Very cool indeed.

Well, my names Ben. I'm from central Pa. Looking to build something that'll use a lot less gas than my jeep. 100-200mpg sounds enticing. I have a bike, a motor, a plan, and doubts. Just looking for some direction and advice here.

So I'm at the drawing board now. I don't WANT to spend more than $250 on the whole project, BUT this could turn into my primary transportation, so it needs to be reliable. I'm looking for something for school/work transport. I have at least one big long hill no matter what route I take. AND I'm about 275lbs. Avg route length is 1.5-3 miles. I have a newly purchased Mongoose XR75 (wallyworld cheapy) and a 2.0/12" Craftsman chainsaw.

So, my doubts are as follows:

I like the bike because of the full suspension, and thats about it. It was $100, and it needs a lot of adjustments(gearing is way out of wack, wheels are out of alignment, and anything that rotates has a wobble to it). Wasn't sure if I should take it back to walmart and get a better platform from a better store or have a bike shop fix it up for $40.

Got the motor working the other day. Carb needs adjusted because the clutch spins at idle, and I suppose a chainsaw shouldn't do that? But my main concern was if this was going to satisfy my, ehhm, BIG, demands. I mean, this motor looks tiny, and the bike and I look, um, opposite. I heard that ANYTHING is an upgrade from a HT, but I'm not so sure.

I planned on doing a rack mount, since there is zero room in the frame. Wasn't sure if I should do a belt or chain drive. Belt sounds easier, but with less satisfying results. I'd like to make a fancy chain drive with selectable gears. As far as pulley/sprocket size, I'm still working that out (translation = ). My big problem is I don't know anything about the motor, as far as rpm's, like when the clutch should work and when I hit my peak power. Because I need that to figure gearing, correct?

So if anybody has ANYTHING to add, it would be much appreciated. Thank You!!

 

[NunyaBidness]

hey Ben
welcome aboard
you came to the right place for your answers
I'm sure someone more familiar with rack mounts will be able to help you better than myself

 

[SimpleSimon]

First, find out the year of manufacture and the model number of the Craftsman saw you own. Second, look it up on the web - there is almost certainly information as regards it available. Third, count your blessuings - if Sears puts their Craftsman label on a tool, it is almost certainly of high quality standards, no matter who built it for Sears.

Most of the Craftsman chainsaws in the size bar range you own run about 2HP power capability, so yes, it'll drag you and the bike around. The bike you bought is of MUCH poorer quality, I assure you, than is the engine. Further, parts are available through Sears. Rack mounting the powerhead is pretty straightforward, if you have even just basic tools. On that frame, rack mounting is your only real choice, in any case. Chain drive or belt drive are both nice to have, but as an utter n00b at the game, I'd reccomend you go for friction drive, simply because it is the easiest to fabricate on your own.

Good luck. There's a wealth of information available about what you want to do here.

 

[oliveclown]

Thanks for the replies. I know the craftsman motor is of high quality. It fired right up with a new fuel line after seven or eight years of storage. My only concern was if it could produce the work I will be asking it to do. As far as friction drive, I don't think that could be one of my options for two reasons, tire wear and slipping when wet. I just don't think it could be as reliable as a chain drive. I don't mind fabrication, I've done a little welding and I've been working on cars for about 4 years now, so a mb should be within my range of capabilities.

Although I fully agree on the bike. I may nose around a few of the bike shops to see what they got instead of keeping this pretzel on wheels, unless someone can vouch for its quality. I reeaaallly wanna keep er. She sure is purdy. . .

 

[SimpleSimon]

Thanks for the replies. I know the craftsman motor is of high quality. It fired right up with a new fuel line after seven or eight years of storage. My only concern was if it could produce the work I will be asking it to do. As far as friction drive, I don't think that could be one of my options for two reasons, tire wear and slipping when wet. I just don't think it could be as reliable as a chain drive. I don't mind fabrication, I've done a little welding and I've been working on cars for about 4 years now, so a mb should be within my range of capabilities.

Although I fully agree on the bike. I may nose around a few of the bike shops to see what they got instead of keeping this pretzel on wheels, unless someone can vouch for its quality. I reeaaallly wanna keep er. She sure is purdy. . .

Polish her up, hang her on the wall as "art".

Then go buy a bicycle.

 

[Mountainman]

Sounds like you have a nice motor to work with there... If the bicycle is in that bad of shape -- maybe another ?? With your experience - building the drive system - as regarding you wishes - should be fun... That little engine -- will surprize you when your MB is up and running !!! Happy Riding from - Mountainman

 

[Alaskavan]

Haggard wrote an excellent thread on home-made rack-mounts. He was talking about mounting pocket bike motors, but with some variation, it should work to rack mount about anything. (The thread on chainsaws and weedwhackers is all about friction)

http://www.motoredbikes.com/showthread.php?t=7996&highlight=tutorial