Male Speaker: So many young people keep messaging me for more details and how to build a motorized bicycle. Well, everyone is different because who knows what kind of bicycle you are going to use or what kind of motor you are going to use. I happened to use this bicycle because I found it in the garbage and it was in working condition. The next infinitely important thing when choosing an engine is that you choose the one that has a clutch on it. Only half of the Weedeater's may have clutches on it and they are using only the better quality ones.
Clutches on Weedeater motors all look a little different that all kind of work the same. You have got to figure out how to attach a small sprocket like for example this 11-2 sprocket to the end of your clutch. On this model of engine the clutch is fully enclosed in other ones, you can still start and have front the clutch sticking out, so you can see what you are working on. Well, some clutches have a swear hole in the middle, and then you can make like I did on this one a sprocket with a little shaft attached to it, with a little square shaft that goes into the hole and the clutch, and so that the little shaft doesn't fall in the hole in the clutch, I go this little end, you know, it is called an end stop.
It just stops the shaft from sliding out of the clutch hole. Here is a little chain side to give you an example of what clutch looks like. It's a free wheeling cup shaped disk, it's got a bearing in the middle and weight set fly out when you have the motor to grip it and start to spin this part. Well on a chainsaw you have this funny little cog thing right here that grips the chain and spins the chain around well that's up to be useless we are trying to make a motorized bicycle or anything else. I used to be a machinist, so I start from scratch and I just make a whole new cup and a sprocket and everything all from scratch in one solid chunk of metal in my machine on a lathe and another machine.
But most of you young guys don't have access to equipment like that because we are talking about $10,000 for the equipment just to make clutch. It is possible take out for example on this model, the big washer either grind this is got removable cog, see you can just remove it or it's not removable maybe either the mart, you just have the grind off or but right teeth with a grinder and try to grind them off really evenly, so you have a concentric circle parallel with this one. Well, whatever method you use, once you get rid of this wrong type of bride car whether you grind it to the you removed it then you have got to buy a small sprocket say anywhere from 10 to 12 teeth to somehow attach to the bell cup.
Well, you may have to open up the whole inside the sprocket to make it big enough to fit over top of everything here, which you had left or you can do that by drilling or grinding, it's be the butt. Then somehow you have to attach that sprocket to here well bracing it with the brass rod and seddling towards my work or in this 90 degree edge where the new sprocket will be sitting on. You could make a weld all the way around here you, the nut may be able to hold it on. Make sure the bearing is in there while you are welding or while you mount your bearing.
On my motorized skate board as you see here, this is the clutch that I made. It was build by one complete block of steel. It's made up of hardened tool steel, my machine dobbles little sprocket teeth; machine to bearing surface inside with a little roller bearings well that's way beyond most people, so you probably just have to try to figure out how to weld a sprocket that looks like that to the bell housing of the clutch and get it centered that's very important.
Your next step on your project is mounting the motor well, every Weedeater has a different way to mount the motor and you got to figure out the way because there really isn't a way. So, I've got a bar here that's relate to the frame and I've got an angle plate here that's relate to the frame, there is a little support brackets where there is no twist in the motor.
So, as you can see the motor, this plate had the cut up here with the middle of the motor that a couple holes spilled into it, it actually will holds already that we are existing in the block of the motor like runs in an angle as well with the frame. At the front end of the motor there is the vertical plate that welds to the bars and a little t-plate comes off as it's related here and counts in places on the engine where they was existing holes, so drew a hole on this little bar and made it fit the engine. First everyone is going to be different. Make sure you know in which way you are engine is spinning when it runs, you don't put their engine on backwards and have your bike go backwards.
The throttle, this is just a shortened break handle. The cable, this is just a bicycle cable from the breaks where the cable attaches to the motor, you had to make a little metal bracket as an end stop to hold the cable in position and my Weedeater had a little tiny piece of elbow on the end of the cable that wen to the hole and throttle. Well, of course Weedeater's throttle cable is a foot long and you need something about three feet long, but you also need that special little end that goes in the hole to the throttle linkage. So, here is how you do it. you cut off a little length of Weedeater's throttle cable with the special little end say maybe that long and you cut off a little piece of paper pipe as a coupler, and then you get a piece of bicycle break cable and figure how long you have to make it once it's in position and you sleeve that little copper coupler over the piece of bicycle break cable, sleeve into little piece of cable you cut up your Weedeater also into that little copper sleeve and cut it as I mentioned.
Then put it on the ground and smashing everything with a hammer that a couple of two cable pieces together, and then you have something just like you see there and you can see that little part that I squish together to join the two cables. Every Weedeater has a wire that goes to the keel switch is shut it off, so you just unhook it from the keel switch, run the wire up to the frame to another switch, one goes to the switch, one goes to the ground so when you push it, it stops the motor. Now the next trickiest part is remove the pedal crank mechanism completely and bearing cups and you have to get a couple of sprockets in a couple of precession sealed bearings. Here is a tiny example of a precision sealed bearing looks like. That's the plastic round here that holds a grease in and common size that you would want to use for your crank shaft that goes with the middle of that would be five inch hole in the middle and outside diameter of somewhere around an inch and a quarter and easily find these bearing supply by just, so you will have bearings in the yellow pages nice CD, I would the CBS equipment they have bearings, blets, sprockets, chains and pulleys.
Every cities has company like this is specialized in drive equipment. The 58 inside diameter, two bearings in there, it only costs about $7 each, which is not a big deal. The big deal is they don't feed inside here, they just flop around the lonely picture sharper and be clear to go through. Well, if you see the metal H and that metal edge that's a cup shaped device I made. The bearing sits in a pocket in a machine cup that presses into the crank.
So under the frame and that's the lip on the edges it sets a distance sort of presses in. that part you have to make some scrap on a steel laid well, you are at your bearing supply place, so you have every kind of sprocket you can imagine. The best kind of chain sprocket to use for motorized bicycle is called 316 roller chain or itself it's also called number 35 change. This is just called a black steel plate sprocket, it has got no dry pub on it and they came already with the 58 inch hole. See you can just stick you shaft through it, put a weld on it, attach it to the shaft. Simple as that. That sprocket cost about nine bucks. On the other side, I got another sprocket, it's about 15, 16 teeth but all the smaller ones come with a little dry hub on them and most of them come with 58 inch hole also.
So that makes so perfect slide it on the shaft, put a little a washer and you'll notice space it from your bearing and your bearing mounting cup. And tighten the set screws or put a little weld on it.
This sprocket assembly it's in the middle of the bike on the crank, it's called the jack shaft assembly. Well, I got exactly the same kind of six inch sprocket and about another one and put it on the back. You cannot use a small sprocket on the back that originally comes with your bicycle that gear issue will be wrong. So, I'll show you how we attached this sprocket to the rear wheel. In this particular bike, I just had a single sprocket, I had a two grind out the hole in the middle of the sprocket or anyway you can think of making the hole bigger so it fits on to the sprocket hub. Then I drill three holes that happened to fit between the teeth the original sprocket and put a little nut and bolt.
Now you can barely see the nut on its side, they are all dirty. The best way to increase the size of the hole in this sprocket is put this sprocket in the lace spin it around and bore the hole out with the boring tool that's actually how I did. So, the ratios that gear is four times smaller than this gear and this gear is three times smaller than that gear, so that's three to one, that's four to one and when you multiply that together three by four, you get a total of a 12:1 gear ratio, which means if I rotate that motor 12 times, the back wheel will turn once that's very important. Weedeater motor run at 7,000 rpm, and with your fat ass on them riding them and then you have a little limited horsepower, they will make it to do about 25 or so, maybe 30 miles per hour, so that's all the horsepower output they got. So that gives you a gear ratio where that motor is running at 7,000 rpm to go that speed. If you use a mountain bike like one of those, they have got a bigger wheel. So, in sort of a 12:1 gear ratio, you might need a 13 or 14 one gear ratio, so you just got to get different size sprockets and just do that simple calculation.
Some people let to use friction drive. They mount a motor over the top of the rear wheel some place back here have a roller on the shaft to the engine, let's say 112 the diameter of the wheel and the press is hard on here try to get enough friction to drive the wheel as everything is spinning. Well, this method sucks whereas your back wheel outlet, it slips when you go through a pedal and it robs horsepower from your engine by all the down force you need to get traction. But, of course, despite far the simplest method. This is the most complex method, but it's the most urge economically pleasing, you know it looks the best, I mean it's very comfortable ride, it's well balanced only ads about four, five pounds of the total weight of your bicycle. So, I would prefer this method, but you need to have access through a welder, a drill, a hand grinder, and of course maybe a lead and milling machine.
So, let's see how this machine starts, it's getting setting a while. Cut it on half choke. It's always on until you push the keel button and give it a yang. Wow! Wonderful. Now as you could see, it's not going anywhere as it has a clutch. If I revert up, the back wheel start to spin, the way it wants to go. Well, as simple as that.
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