I'm thinkin' agin

deacon · #1 (**permalink**) 09-30-2008, 10:14 AM

I saw a mount in a magazine Joe sent me. I think it would be ideal for a rear mounted WW on a full suspension bike. The full suspension I have has no place high up to hook the engine. The reason it never worked well on the rear before is that the engine mount was in the way of pedaling. Like it or not the bikes I build have to have the ability to pedal them home when the drive goes screwy.

So I think I will give it a shot with the bike I have. It's going to be a miserable day so why not.

It's not like I don't have enough bikes to ride if the weather clears up.

Spikedfox · #2 (**permalink**) 09-30-2008, 02:08 PM

Okay first thing, i dont know you well enough yet, but whenever anyone says anything remotely like "Well, I got to think'in" i get a horrible sence of foreboding.

especialy when i am about to say it because i have cauht myself following that with some very bizarre things like, "how did stegasuareses mate?"

but, on the other hand, if you keep buildin fun bikes, i may just have to try to talk you out of one one of these days (i keep lookin at your china girl in unfittin ways anyway)

deacon · #3 (**permalink**) 09-30-2008, 03:12 PM

Well I'm going to put her in storage till spring then off to craig's list with. her. Quite possibly something inappropriate will happen to her there.

ps I didn't get started on this project. The sun came out and I have been test riding the 33cc chainsaw bike. It does all i could ask of it. I would like for it to feel less tentative doing it but I can live with it.

comfortableshoes · #4 (**permalink**) 09-30-2008, 03:39 PM

Deacon I was thinking that if you go a speedometer you'd feel a lot safer on these bikes. When I first started riding them I was sure I was traveling at warp speed, you know? But when I got a speedo it calmed a lot of my fears down- Knowing I was going 15 or 20 was a good thing.

I started out with a crappy one from Target- cost about $10 and wasn't worth a turd- couldn't tell speeds after 15mph- useless. Then I upgraded to a $20 sigma 800 from Richard's Sporting Goods and it's rated up to 50MPH. It's very accurate and is pretty simple to use. It is wired.

Well worth it.

deacon · #5 (**permalink**) 09-30-2008, 04:50 PM

I have a speedometer on the china bike. I have a pretty good feel for the speeds. Funny thing but the bikes now that the tension is constant don't go as fast but have power all the time.

The motor being engaged 100% of the time helps to control the speed so there is no runaway train feeling with the bike. I think having the drive fully engaged probably makes the gain and loss of speed more consistent so less intimidating.

One of the bikes still has the sending unit from my old speedometer for ebikes. I am just glad to have bikes that finally have some sense of control. I have learned another valuable lesson.

By the way I must have ridden 15 miles today on the 33cc CS bike and the jbweld has held up very well indeed. Since I have time tonight and I will probably ride the 42cc tomorrow I think I will put a skim coat on the drive. Just where the drive touches the tire. I can see that pretty clearly now.

I am also pleased that the tire doesn't show a lot of wear yet. So shoes you are probably right about the jb weld.

comfortableshoes · #6 (**permalink**) 09-30-2008, 05:24 PM

I 'm glad that the jbweld and sand finally worked right for you. that stuff is awesome. I'm getting ready to go out for a ride a little later today. Ic an finally breath clearly and the roads are finally dry. Though it's supposed to rain again tonight and all day tomorrow.

deacon · #7 (**permalink**) 09-30-2008, 06:28 PM

I didn't check it out really well till just now so I didn't know what it had done. Sometime today and it could have been first thing I wore down all the knobbie areas. What is left is an even coat of jbweld with the consistancy of very fine sandpaper. Probably because I used the craft store sand which was very fine. I know it pulls fine maybe it well keep the tire wear to a minimum. It is much finer than the sand paper I used.

I think that more coarse sandpaper might have pulled a little better but this seems to do fine. If I need more pull I might just get a more coarse sand. But the sandpaper seemed to do a number on my tires. I think I will stick with this a while. When I put the 42cc away tomorrow night I might just coat it to kill that file like surface, plus it is wearing down in the center. I don't want to have to replace the peg because I have the only nut for that saw welded to the peg.

deacon · #8 (**permalink**) 10-02-2008, 11:55 AM

Back to the original reason for this thread. I am moving the engine from the front of the full suspension back to the rear. The front of it is way to unstable because of the bumps. The rear wasn't any better but I'm using an mount idea from the fifties. It's backwards to how I mount engines but it is the only way a rear engine will fit since I downsized the rear wheel. I'll try to do pics as I go along. If I abandon it in the middle you will have wasted the space I take up though.

This is the first part of the mount change. It gets two braces (one on each side) bolted to the side of the new metal and then to the bike tube. Im going to secure it with a 3/4 water pipe clamp straightened out.

then I'm going to just move the motor mount from the front to the rear and hook the scissor hinges on with clamps as well. The motor will swing toward the seat. That is backward from how I usually do it.

deacon · #9 (**permalink**) 10-03-2008, 06:12 AM

It was easier than I ever thought it could be to make the changes in the bike. It did require a bit of drilling ect but it all came together in less than a day.

I used a couple of "L" brackets and a chopped up fence fabric tension bar to build the base for the engine mount. After that it was pretty much a routine build till time to hook up the controls. I keep thinking I'm going to have to move away from the brake lever clutch and go to a home made lever. the brake lever just doesn't have quite enough throw. It's a shame too.

I have the lever I built into the bike's frame on this one. I am going to try it without the brake lever first to see what it does. I have the ability to use home made levers on all my bikes and I might just have to do that.

deacon · #10 (**permalink**) 10-03-2008, 07:47 PM

I thought sure today was going to be just ride the WW bike. Right never think anything is as easy as it seems.

When I raise the engine the geometry changes enough so that the throttle floods the engine. I spend hours trying to find a good adjustment. Finally I gave up and ran a sheathed cable all the way from the handle bars to the carb adjustment. I had to add a small spring to help it return but it seems to work okay.

I removed the hand clutch and use only the suicide clutch on it now. It seems to do better but I can't be sure because....

The plastic tank I was using for a gas tank cracked. I spent the late afternoon retrofitting the original gas tank in a different location. The glue on it is drying now. I am also letting the first coat of the jbweld/ craft sand dry. I think that fine craft store sand might just be the trick for me. It is the consistancy of very fine sandpaper but the 42bike hums with it. I can't judge the tire wear yet.

One more thing, I found a screw missing from the engine mount. I decided that since i was there I would try to beef it up. I drilled out the mount on the engine and installed a 1/4" bolt, nut, and lock washer. I did both top ones like that since the other one was loose as well. I think I caught it before it cracked the case. If not I won't be buying any more weed whackers. I can't seem to keep the cases together. They need to be checked and I just can't seem to remember to do it. So If this one goes I will probably look for another chainsaw engine.

The craftsman 42 I got on ebay for 35 delivered. I took it with some parts missing but I would have ripped them off anyway. The 42 is plenty fast for me once I got the tension adjustment right and dumped the hand clutch lever.