Wednesday, August 25, 2010

Riley OCC Build Post #2

Yesterday, I began posting coverage of my friend Rob Riley's build of a customized OCC motorized bicycle. The story continues today...

On to primering the whole tank and shooting some paint on it.I shot 3 coats of primer/sealer over the tank sanding out any dust that happened to get in the primer.After I let the primer dry for a couple of days, I started shooting the paint. The paint that I used is metallic black laquer, and I shot it through a touch up gun.
4 coats of paint, wet sanding with 1200 grit paper between each coat except for the last coat. 4 coats of clear laquer. I wet sanded the final coat of clear with 1200 grit paper, and then rubbed it out by hand with rubbing compound because I don't have a buffer. The paint job took me about a week to do. I am not a professional painter by any means but I have done quite a few paint jobs on motorcycle tanks and model cars.

Now that the tank was done, it was time to move onto to building the rest of the bike. This is not my first motorized bike build, it's my second, so I know from experience what all needs to be changed, modified and replaced with better quality parts on these things.

I bought an 80 c.c. 2 stroke engine kit off e-bay for around $140.00. The engine kits come with everything you need to turn almost any bike into a motorized bike. Here's how the engine looked right out of the box.

I masked off everything except for the cylinder,cleaned it to get any machine oil off of it and sprayed it with hi-temp gloss black engine enamel.

After I did that I decided to try and polish the aluminum side covers on the engine. The aluminum is not the best, but it polished up ok. The covers had a lightly sandblasted looking finish, so I had to sand them with different grits of sand paper starting with 200, all the way up to 1200 to get them as smooth as I could. Then I polished them by hand using aluminum polish. It was a lot of effort for the results I got. I was hoping to get more shine from them but I don't think it's possible with this low quality cast aluminum. I don't have a buffer, and that's why I had to do the polishing by hand. Maybe if I had a buffer, i would have gotten better results, but they look pretty good to me as they are.

There is no way to mount the engine to the o.c.c. bike frame without a custom mounting bracket. I bought the bracket off e-bay and it cost me $25.00. I probably could have made one, but buying one was easier, and faster. I did slightly modify the bracket to make it stronger. The bracket gives you  2 pipes to mount the engine to, and it also off-sets the engine to the left about 4 inches, which allows the engine chain to clear the fat 4 inch wide rear tire.
Here's what the pieces of the bracket look like after I painted them gloss black. This piece mounts on top of the bottom tube on the frame.

This piece mounts on top of the above peice, and the engine mounts bolt around the 2 pipes on this bracket.

The 2 smaller pieces in the front of this piture mount under the bottom tube on the frame. You have to drill two 3/8" holes in the frame tube and run bolts through the brackets and the frame tube. The brackets sandwich the frame tube between them and it's a pretty strong set up. I took it one step further to make it stronger and I had my neighbor grind down and re-weld the questionable welds that were holding the 2 pipes to the top bracket. I also put steel sleeves in the holes that I drilled in the frame tube, to keep the frame tube from getting crushed or distorted when the bolts that hold the brackets to the frame get tightened.

Mounting the bracket to the frame was pretty straight forward and so was mouting the engine to the bracket.  loc-tite, lock nuts and lock washers were used on everything. These engine kits come with all the bolts, washers and nuts that you need, but they are VERY cheap and they break and strip very easily. So all of the nuts, bolts and washers were replaced with higher quality ones that I got from the hardware store. I think I spent about $15.00 on nuts, bolts and washers.

Mounting the sprocket to the back wheel is kind of a trick on the o.c.c. rim. Most of the time, you can just bolt the sprocket on with no problem. You get the sprocket, 2 very heavy rubber bushings, and a 3 piece clamp that goes on the inside of the hub. 9 bolts go through the holes in the sprocket , then through one of the rubber bushings, then through  gaps in the the spokes, through another bushing (on the inside of the spokes) and then the 3 piece clamp goes on with lock nuts and lock washers holding it all together. With the o.c.c. rim, I had to elongate each of the 9 holes in the sprocket slightly because the bolts would hit the hub where the spokes are connected. I used a drill and a drill bit to slowly elongate each hole a little at a time until all the bolts cleared the hub and went through the holes straight.
Here's the sprocket mounted to the wheel.

Now that the engine is mouted to the frame and the back sprocket is on, it's time to install the engine chain. The engine chain is a heavy duty motorcycle style chain, and for the o.c.c. chopper, the chain that comes with the kit is about 5 links too short. So I had to order a length of extra chain with 6 links in it. Once the chain was lengthend and on , I discovered that the chain was rubbing on the rear brake caliper and the brake pad . I had to shim up the caliper on the left side, and cut about 1/4 of the brake pad off. Doing this, greatlly improved the way the brakes work. the only thing I can think of is that by shimming and slightly bending the caliper, the angle was changed and it makes the brake pads grab the rim better...I have no idea.
Here's the modified brake caliper.

Man, this bike is really taking shape. Come back tomorrow for the 3rd installment of the Riley OCC Build.