Email: ELongMotorBike@gmail.com to subscribe for updates on this project -You're email will not be given out in any way shape or form. I will simply email you at the provided address with updates regarding progress on this project. TODO: -Chain -Throttle -Killswitch 10/14/08 -I talked to the guys at the bike shop and they explained it all to me. Turns out bikes with multiple gears use a size #35 chain meaning the gears and chain have a 3/8" pitch. Bikes with only one set of gears use #40 chain which is 1/2" pitch. They make the ratcheting 1/2" pitch sprockets like on the back wheel of multi-geared bikes and I think the guy told me I could get one of those for about $10. Depending on how the back wheel drops out of your bike you may need to get a pulley to get the right tension on the chain. They had one of these at my bike shop for $20. If you're rear wheel has a vertical dropout, then you will almost definitely need this tensioner. If it slides in from the front or the back then you may be able to get the right tension by sliding it forward or back some. They also told me that I could get the chains for about $7 each. So I figure I'm about $50 to $70 away from finishing this thing, but funds are running kind of low lately so I'm going to have to put this project on pause for a little bit. 10/13/08 -Ran into a bit of a snag over the weekend. I got everything all hooked up and ready to get the chains put on. Took it to a local bike shop only to find out that the new sprockets that I got on the clutch and the jackshaft don't match up to the chain that's currently on the bike. Wikipedia says that most bikes today use a size #40 chain. Well, it looks like most bikes actually use #35 chain. Maybe non-geared bikes use size #40 chain. I'll have to look into it more. Anyway, here's some shots of the custom jackshaft. I just cut the pedals off and ground down one of the sides to fit a 5/8 inch sprocket.   9/30/08 -Mounted the engine on the bike complete with the custom drive shaft and my centrifugal clutch. Just have to finish hooking up the jackshaft and get the chain on it and I should be good to ride. I think I'll head to the bike shop today and see if they do custom chains there. Here are some pics of the mounted engine.     9/24/08 -DRIVESHAFT completed! Finally got the time to get in the shop and make the piece on the lathe. It's not all pollished, but that's fine since no one will see it once it's on the bike anyway. I need to add set screw holes and thread the nub on the end for a nut and washer to hold the clutch in place, but that won't take very much work. Anyway, here's some shots of the near final product. 9/12/08 -Here's a basic design for the drive shaft connector that I plan on making for this system. Hopefully I'll be able to get in the shop next week or the week after.  9/10/08 -One of the teachers at my old high school is going to let me use the shop machines there so I can make my drive shaft connector. -I got my second jackshaft sprocket in the mail today. Just gotta work out exactly how I'm going to attach it.  that I picked up from a guy on Craig's List. He told me he thought a gasket on the carb was bad. I ransome carb cleaner through the system and it started up for me after a few tugs on the starter. I did have some trouble keeping it running reliably though. I figured I'd tear down the carburetor and see if I could find anything wrong. The gaskets looked good as far as I could tell. Here's some shots of the tear down.          9/1/08 -I finally mounted the engine on the bike.     8/28/08 -I've passed the point of no return. I hacked off the end of one of the crank arms on the pedals.  I left the nub on there so I can use the original pedal gear. -I'd like to use the original gears on the rear wheel, but that's beginning to look very unlikely as I'd have to find a .86 Inner Diameter Sprocket with 8 teeth to get the cmorrect ratio. A rep form a custom gear manufacturer told me that the smallest sprocket they could make with an inner diameter of 7/8 inches is 10 teeth. I need a 7/8 inch inner diameter sprocket to fit the other side of my pedal/jack shaft.   -I'm going to attach the L bracket to the bike frame using some U bolts.    8/25/08 -It's been a while since I've been able to work on the bike. Lot's of stuff going on. I got my clutch in over the weekend though. It's got a 5/8 inch bore. I think I'll have to make a custom piece to fit it. I'll have to find someone with a lathe. -Took the crank arm off my bike tonight. turned out to be easier than I thought it would be. If I can saw off the ends of the arms I think I'll use that as my jack-shaft. That will be a lot easier than fabricating a whole new one. Anyway here's some shots of the disassembled crank arm. -Here's the crank arm off the bike. The nub sticking out of the right arm is to hold the original pedal sprocket.  -Closer shot of the crank arms. I want to cut the arms right past the nub and right around the curve on the other side.  -Crank arm bearings   -Here's the original bike sprocket. It's about 52 teeth, so I'll need to find a a 12 tooth and a 42 tooth sprocket for the other end of the crank-shaft and the wheel.  8/19/08 -I've been looking at my speed calculations all wrong. I've been using diameter instead of circumference in my calculations. Turns out I'll need an overall gear ratio closer to 18:1 to get a top speed of about 30MPH. Looks like I'll have to remove the pedals and put in a jack-shaft to reach this. Here are my calculations. -I got a clutch off ebay for just under $30 after shipping. It has a 5/8" bore and a 10 tooth sprocket attached and uses #40 size chain. 8/13/08 -Found a centrifugal clutch here. Ends up being just under $35 after shipping. It has an 11 tooth sprocket attached. There's a couple 60 tooth sprockets on that site too for about $10. I figure that the drive shaft will spin about 8000 RPMs. That being the case using a 12/60 gear ratio should give me a top speed of about 30MPH. Shipping stays the same so these two items would run me just under $45 from here. I'll keep looking for now. -Looks like some good info about clutches and other stuff here. -Ranger at motorbicycling.com recommended this clutch. 8/11/08 ============================================================================================ -Ok, took some measurements and checked stuff out today. My bike frame is 1" diameter tubing. I took the plastic case off the engine and noticed that the drive shaft is broken at the end.   The end that holds the square crank shaft split almost right down the middle and broke off. That's why the string wouldn't spin when the engine was running. -I talked with my uncle, who's done all kinds of work on engines and racing go-karts, over the weekend and he gave me a lot of new ideas. I thought that weed eater engines had clutches built in at first, but they typically do NOT with the exception of professional equipment. My uncle thinks I could probably get a clutch for about $30. I was originally hoping to complete this project for about $20, but now I'm thinking more like $50 and it will probably end up being more than that. -So, I need a clutch, a crank case, a couple of bearings for the crank case, a sprocket and a mount for all that. I'm probably forgetting something, but that's the major stuff I can think of right now. 8/7/08 ============================================================================================ -SUCCESS!!! Got the engine running thanks to some help from deacon over at motorbicycling.com. 8/6/08 ============================================================================================ -So far I have an old 10 speed bike and a homelite trimmer. I have a good idea of how I can mount this engine as long as I can get it running. -This site has been helpful in finding info to get started and there are a lot of active members. http://motorbicycling.com/ -Here's a pretty sweet looking tutorial for small engine maintenance and repair http://www.repairfaq.org/sam/lmfaq.htm -Here's a few shots This is my bike.  Here's a closer shot of the gear system.  Rear sprocket system.  This is where I'm thinking of mounting the motor.  Here's the Homelite weed eater engine I've got.  These 4 bolt holes where what held the trimmer arm on the motor. I want to use these to mount the motor on the bike.  Got this sprocket off of another old bike. I'd like to weld it to the drive shaft of the Homelite motor to use a direct chain drive system.  Only problem is, it looks like the sprocket was press fit onto the crank arm for the bike petal. May have to do some work with the dremel.  -MORE TO COME!!! |
