motorized Schwinn Stingray modified for adults - build details

B

Blaze

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Here are the build details and things to watch out for when building a bike like this one. I will try to keep the comments in the same order as the thumbnails posted below.

1st photo - side view. Don't use the stock seat. It looks great mounted directly to the frame, but does not belong up in the air. Get a seat post that bends back over the fender and install a nice springer saddle. Also, ape-hanger handle bars are the way to go here. Very comfortable way to get your grips up where you want them.

2nd photo - automatic centrifugal clutch. Standard on every bike I build. Auto clutches are just the way to go, and the great thing is that the motor mount sets the whole motor off to the left, so you don't have to modify anything to get the clutch to fit in, unlike every other bike I've built. It just fits perfectly.

3rd photo - frame spacers. I added a few washers in between the hub and the frame on the left side to get more clearance for the sprocket. More on that later (8th photo).

4th photo - clutch lever. For auto clutches, I always mount them out of the way. You don't need to use it for anything but starting the bike, so I always mount it where it won't interfere with the grips. Looks a little wierd, but it's practical.

5th photo - exhaust mount. Hose clamp. That's as simple as it gets. I used some of the rubber sprocket shim to cushion it against the frame. Don's tighten the hose clamp too much if you use a setup like this. If you keep tightening it, the muffler will get pulled up too high.

6th photo - plug wire. I cut the plug wire so short all you can see is the rubber plug cover. Looks very clean, and is a good fit for the bike.

7th photo - speedometer. Donated and installed by Johnny. No real reason to put that up here because it's easy to put on. I really just posted it because it looks so cool.

8th photo - sprocket spacers. Here's where we did a little work. The 36t sprocket from spookytooth did not line up with the hub adapter from Livefastmotors, and the center hole in the sprocket was too small to fit over the center of the adapter. I had to file the sprocket's bolt holes to fit the hub adapter. Then, rather than enlarge the center hole of the sprocket to make it fit flush against the adapter, I decided to use a nut as a spacer between the hub and the adapter. It gives you more chain clearance for the tire. This is why I added the frame spacers in photo 3. To make up for the sprocket being moved out from the wheel. In the end, it gives you great chain/tire clearance, and everything lines up well. If you do this, you will need new sprocket bolts. Later, I will edit this to include the Ace Hardware part numbers for the bolts, washers, lock washers, and nuts that I used.

That's it for the photos. Here are the things you need to know to avoid the problems I ran into, and it can really save you a lot of time if you know before you start to build...

1. Livefastmotors has a great kit for converting these choppers. We got the $185 complete conversion kit (this is separate from the motor kit), which included the motor mount, the long exhaust, and the hub adapter to mount the sprocket to. I was seriously impressed by the high quality of this kit. It made this bike the easiest one I have ever built.

2. You need a longer chain than what comes with the kit. When you order your kit, make sure to get an extra chain. If you order from Livefastmotors, they will include a longer chain for free if you request it for the chopper build. The one thing that wasted more time than anything on this build was trying to find more chain. These chains are not easy to find (at least I had a hard time), and can be expensive when you finally do find them. For this build, I finally had to get a heavy BMX chain, which should have been the same size, but was just barely off. After feeding 6 BMX chain links into the motor sprocket, it would bind. I had a few original chain links from another build, but still had to use 4 links form the BMX chain, so I broke the chain 4 times and installed one single BMX link at each break just to keep them away from each other. It worked great, but it was a huge waste of time.

3. Your sprocket will probably not fit the hub unless you get it from Livefastmotors. Be prepared to do some filing. I have been buying the 50cc motor kits (sold as 80cc if you believe it) with automatic clutches included for just over $200, so I'm probably not going to switch vendors any time soon. Plus, we wanted a 36t sprocket to compensate for the small rear tire, so we went ahead and ordered it from Spookytooth. Not too much work, but totally avoidable if you get the 40t from Livefastmotors.

4. You will have to bend the exhaust just a little to get it to fit right. I recommend having access to a vice. I did not. Johnny and I laid the exhaust on carpet and both stood on it as I would pull it to bend it a little. I don't recommend that method if you can avoid it. It sucks. And if you bend it while it's on the motor you have a pretty good chance of breaking an exhaust stud. I didn't break any, but I really did push my luck a little there.

If I think of anything else, I will edit this post to include it. The other stuff is basic to any motor install for any bike. Lube the cables, loctite the bolts, use better gasket material, blah blah blah.

Anyway, if you build one of these bikes, these tips should make it easier than when I did it, and that was still pretty easy compared to most builds I've done.
 

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very good/ detailed post!, but i have a question.....how did ya mont yr tank? i trilled the frame, and did the mount upside down, and it worked great for the 1st 150 miles, but 2 days agao, i broke the back tank mount, not the tank stud, in too, and on the ride home it stripped the screw/ hole on the front one. so now i have some really long sheet metal screws in there with coarse threads, but ts the same size as the hole, so at best it just keeps the tank from falling off. i just hold it with my knees as of now..... im gonna ask my dad for help, if ya did the same thing i did... (hate doin that, and making himn stop workin on the harleys though...)
 
Question about the auto clutch. It still has a clutch lever so it's only used to start the engine? Then it will keep idling when stopped?
Won't that wear parts down inside more than a conventional manual clutch?
I'm a bit lost on that whole concept. I would think it would be better if used like a manual clutch.
 
very good/ detailed post!, but i have a question.....how did ya mont yr tank? i trilled the frame, and did the mount upside down, and it worked great for the 1st 150 miles, but 2 days agao, i broke the back tank mount, not the tank stud, in too, and on the ride home it stripped the screw/ hole on the front one. so now i have some really long sheet metal screws in there with coarse threads, but ts the same size as the hole, so at best it just keeps the tank from falling off. i just hold it with my knees as of now..... im gonna ask my dad for help, if ya did the same thing i did... (hate doin that, and making himn stop workin on the harleys though...)

The tank is just mounted temporarily with the back bracket only. Eventually, it will be mounted the same as yours, though. The difference is that I won't use sheet metal screws. I have a tap and die set, and after I drill the holes in the frame, I use a tap to thread them so I can use fine thread machine screws. I don't know if it will prevent whatever kind of damage you got, but I guess I will find out.
 
how the auto clutch works

Question about the auto clutch. It still has a clutch lever so it's only used to start the engine? Then it will keep idling when stopped?
Won't that wear parts down inside more than a conventional manual clutch?
I'm a bit lost on that whole concept. I would think it would be better if used like a manual clutch.

Yes, the clutch lever is only used to start the engine. Yes, it keeps idling when stopped. No, it does not wear down the clutch. I know, it sounds weird.

This works because the auto clutch kits actually have TWO clutches in them. A manual AND an auto (centrifugal). Both clutches must be engaged in order for the running motor to drive the rear wheel. The manual clutch is used to pop start the bike. Once you engage the manual clutch to get the bike started, you just leave it engaged. The centrifugal clutch must be spun fast by the running motor to engage automatically. That way, if the bike is idling, the manual clutch is engaged, but the auto clutch is spinning freely. When you rev the motor, the auto clutch also engages, then the bike moves forward. Let off the throttle, and the auto clutch disengages again.

So the next question is, how does the motor turn over when you pop the manual clutch, if the auto clutch isn't engaged yet? There is a one-way bearing installed on the auto clutch specifically for the purpose of using pedal power to start the motor. That way, with the manual clutch engaged, the motor can turn forward without driving the wheel, but when the wheel moves forward, it will drive the motor.

I guess at first it might sound like you just let the bike run and make the clutch plates slip, but that's not the case. It's actually pretty well designed.
 
I see now that with two clutches the manual clutch part would actually last much longer.
Pretty cool.
Thanks for explaining all that,Blaze!
 
The tank is just mounted temporarily with the back bracket only. Eventually, it will be mounted the same as yours, though. The difference is that I won't use sheet metal screws. I have a tap and die set, and after I drill the holes in the frame, I use a tap to thread them so I can use fine thread machine screws. I don't know if it will prevent whatever kind of damage you got, but I guess I will find out.

actually, i have a tap/die set also, but it strippped the threads, with all the vibes. the sheet metal screws are just temporary...
 
OK, that makes sense. I guess I will try some red loctite and see if that helps any.
 
what i plan to do also. i also have some jb weld..... might use a dab of that., but over it, so i can chissel it off in the future.
 
i mounted my tank mounts useing 1/8 inch steel rivets,it has held up perfectly
 
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