ryobi weed eater bike

[matman55]

he everone, im new here and i need some help with getting some info on how to put a 32 cc ryobi weed eater enging with a friction drive onto my 2011 huffy beach cruiser,i also need some ideas on the mounting of this engine.sadly i cannot upload any pic but the engine is just run the mill shape, i dont know the year but on the side it says"this product meats the cali. emisions requirements,so its sometime after that it was made.i am heavy set(230) so this engine need TORKE!!!!!in the end i hope it will be bada** to ride,Thanks!

[cumminsbayou4x4]

there are place to bolt it to like the muffler bolts and stuff

[landuse]

Welcome to the forum Matman. I have put a weedeater on a mountain bike, and it was also a Ryobi. Mine is a 30cc though.

I also decided to go with friction drive, as I didn't wanto to mess with chain or anything. I am just going to post a couple of pics of my build, and then if you have any questions you can ask.

2 Websites that were really helpfull in my build were:

www.motoredbikes.com
www.motorbicycling.com

[landuse]

And a few more.

I used springs and turnbuckles to hold my engine down on the wheel. You must make sure that the tyre you use is mot knobbly. Friction drive works better on smoother road tyres.

The roller I used is made of mild steel that I had machined to 1" diameter and drilled and tapped to fit the shaft of the motor. I first tried to use BMX pegs, but their diameter was too large. Just remember, a smaller diameter roller gives you more torque but less speed.

I used 1" square tubing fr my frame, but that was a bit overkill. You can use much thinner than that. It was all I had though.

I am going to make a scissor clutch for myself sometime soon so that I don't need to push start the engine each time I stop.

[matman55]

awsome,thx for the ideas!i am not really mechanicaly oreinted,so i not gonna mess with the clutch, once i get this bike started im not gunna stop for much(except for cops,dogs,oncoming speeding trafic,ect)After i posted this thread i went to go look at how ill mount the engine,i i came up with an idea for the mount. in the picture of the bike the is a rack in the back, im going to screw the engine onto that luggage rack.for some strange reason the exsitining screw holes from the long skinny part of the ww aligned
perfectly with the rack.and im also going to use some of the fender supports(since i took the fender of) to hold the engine up as added support.also you were talking about spring and stuff. Is that stuff necessary?

happy trails!

[matman55]

i dont think the pic showd

woops,wasnt done.is using different diameter pegs just like shifting in low and high?

[landuse]

My springs and turnbuckles pull the engine down onto the back tyre to increase friction. If I didn't have them, then the roller would just slip over the tyre. If you have a static mount that ensures that your roller has permanant pressure on the tyre, then you are OK. Without this downward pressure, you aren't going to be going anywhere

Post some pics of what you have so far. I am interested to see what you will be doing

[landuse]

Using a smaller diameter peg is like gearing lower (more torque less speed). Using larger diameter peg is like gearing higher (less torque, more speed). I found that I needed to gear lower because my engine is quite weak, and I needed a bit more 'oomph' to get going

[matman55]

ok,sadly i dont have a camera to use, and my mount is static and should be very solid.if not ill steal some straps from my dad and strap the engine tighter to the wheel.and i know what
you mean by oomph,try towing 3000 pounds with a 71 super beettle.

[matman55]

hey,does anyone know if taking off the entire exauhst stuff of a weed wacker will do anything great?i was taking it of to inspect it and the question poped into my head.just wondering

Thanks!

[landuse]

Originally Posted by matman55

hey,does anyone know if taking off the entire exauhst stuff of a weed wacker will do anything great?i was taking it of to inspect it and the question poped into my head.just wondering

Thanks!

Because it is a two stroke, it pretty much needs the exhaust to run optimally. I would not remove it

[Jake.B]

Cleaning them after long years of use helps alot, i made one of these a while ago. I ended up getting a rubber boot/cover type thing to slide on my spindle. It greatly increased friction traction and my tire lasted so much longer. Turnbuckles are wonders with these set ups for tightening to the tire, i want to build another one of these if i can find a dirt cheap engine. They are loads of fun.

[landuse]

I just wish mine had a little more grunt. I am thinking of turning the spindle down a little bit more to give me some more torque

[matman55]

is it normal for the engine to be compleatly upside down!thats how it is on myne,just wondering.

Also,is there any cheap way to put a clutch on it?i decided i dont want to push start it everytime i stop,which dosent really matter since i dont have any braking system what so ever.

[landuse]

Originally Posted by matman55

is it normal for the engine to be compleatly upside down!thats how it is on myne,just wondering.

Also,is there any cheap way to put a clutch on it?i decided i dont want to push start it everytime i stop,which dosent really matter since i dont have any braking system what so ever.

No, I don't think it is normal. You will have the fuel tank permanantly upside down. Mine is the right way up, at a slight angle (the angle of my bracket).

For a clutch, you can do a simple scissor clutch. Have a look at the pics below. They should give you an idea of what I am talking about. It uses a cable that pulls 2 the engine bracket up off the wheel.

[matman55]

ok,so its like a pivot for the engine to get off the wheel.do you lock it in place when it is on the wheel?

[landuse]

You don't need to lock it in place, cos in this bikes case, as well as mine, we have turnbuckles and springs that hold the bracket onto the wheel. When you pull the "clutch" handle, you are basically lifting the engine against the springs and turnbuckles that you are using. When you release the "clutch" the springs and turnbuckles pull it back onto the wheel.

You can see the springs in the pics

[matman55]

someone need to sticky this thread.there is alot of good information for someone trying to make a MAB for the first time.

[landuse]

Originally Posted by matman55

someone need to sticky this thread.there is alot of good information for someone trying to make a MAB for the first time.

Threads only get stickied if there is contents that will help everyone on the site.

This thread can easily be found doing a search though, as well as all the other motorised bicycle threads

[matman55]

so,i jsut thought of this.

if the roller is spinning at 5000 rpm and assuming theres little to no slippage that tire is spinning at 192.3 rmp.right? the way i came up with this is 5000 / 26 since the roller im using is 1 inch and the tire is 26 inch for every 26 revs of the roller there is one rev of the tire,so scale that upand i got 192.3 rev of the tire for 5000 of the roller.does that seem right?