4 - stroke Schwinn Stingray Chopper occ

Related to this post: https://motoredbikes.com/threads/pr...chopper-and-im-looking-for-some-advice.50872/

Donnor bike:

Since this is not being an standard build (as expected) I'm going to describe how I'm solving the issues that I'm having, I hope it will be useful for someone.

First thing, choosing the motor kit: after digging and asking around I decided to go for
I ordered this kit: http://www.bicycle-engines.com/49cc-4G-T-Belt-Drive-Complete-Gas-Powered-Engine-Kit.html
I didn't know if to get the 100 or the 80 tooth pulley, I asked on the chat that they have and.... I believe the person behind didn't know much about what she was talking about... I asked which configuration will be faster and she told me the 100 tooth... After checking the manual that comes with the engine, that is wrong, 80 has a "faster" ratio, 100 is for better hill climbing and torque. Because of this I ordered a smaller sprocket (36 tooth), I'll get a Engine rpm to bike wheel rpm ratio of 18, close to what you get with the 80 on the transmission and a 44 on the wheel (17.6).
[UPDATE]
After contacting BE, they are sending me a 80 tooth transmission to exchange with the 100 one, I don't have to pay for anything, amazing customer service!

Pieces I've ordering so far (updated on Apr 2018):
- 49cc 4G T Belt Drive Complete Gas Powered Engine Kit - 80 tooth transmission (from Bicicle-engines) (firt transmission was a 100 tooth by mistake, exchanged with a 80 tooth)
- 2 Piece Muffler "Poo Poo Pipe" Deluxe For 4 Strokes
- Flexible muffler tube (eBay)
- 36 tooth sprocket (Amazon)
- 40 tooth sprocket (Amazon) <- using this one
- Sunlite D-Cruiser Handlebar, 32" W x 13.5" H x 7/8" - Hi-Rise handlebar
- 2 x 2,5 inch U-clamps with nuts and washers
- Front wheel, being a 24'' back wheel with free-wheel to install disk brake
- Disk brake kit for free-wheel (BlueSunshine Front and Back Disk Brake Kit - 160mm For 80cc Gas Motorized Bicycle - Amazon)
- Front fork with suspension

First thing is holding the motor to the bike, the engine bracket that comes with the motor si not compatible with the frame, and indeed, there is no much room to play around in the frame, so I have to remove pedals, bike chain and the chain cover, after that still, really tight, so I cut a portion of the chain cover holder, like in the picture:

After thinking about different options, I come up with a solution, using the central part of the bracket drilling 4 holes (picture only has the first two) on each side of it, so I can use 2 u-clamps to hold it to the bottom part of the frame of the bike

After first try, looks like it is gonna make the trick, the round part of the u-clamp is kind of the same round that the frame, so it adjust well, on the other side, part of the unthreaded u is coming out of the bracket, so I need some washes or something, and of course, I'll have to cut the u, it is way too long.

So far Is what I did (as October 8th). I'll keep updating as I work on it.

November 5th update -> https://motoredbikes.com/threads/4-stroke-schwinn-stingray-chopper-occ.51001/#post-451003

Video of the first start of the motor (Nov/05) -> https://motoredbikes.com/threads/4-stroke-schwinn-stingray-chopper-occ.51001/page-2#post-451198

 

[Frankenstein]

Updates:
View attachment 81020

View attachment 81021

Pedals pointing forward, big screw passing the pedal hub.

Still waiting for the front fork.

So you're forgoing functional pedals?

 

[dmopedMA]

So you're forgoing functional pedals?

Not forgetting, there is no room for them, at least for now...

EDIT: Reading on the way.... yes, forgoing to pedal.

 

[dmopedMA]

Here is a picture of how it looks with the new fork:

Of course, I have to change the handlebar stem, right now using part of the old fork temporary. Planning on adding the fender and front brake (still deciding and checking for options)

EDIT:
Even that this fork is shorter than the original fork, somehow angle is different, so it ends up having the front wheel a bit closer to the frame, becaming a bit higher than with the original fork, so, not bad.

 

[dmopedMA]

Here we are back.

I'm working with brakes now, since the new fork has disk brake holes, I went to the bike shop and I got a 24'' back wheel with free wheel, and I ordered this kit from amazon:

I'll use only the front one, but it was a good price (I guess not the best quality) and I may want to try to install the back disk brake at some point...

I'll keep you posted with pictures and impressions when I install it.

 

[dmopedMA]

That's how it looks with new front wheel, disk brake and front fork.

Now looking for solutions to add suspension to the seat, I'm thinking about something like this:

https://www.bicycledesigner.com/bik...bar/cuda-suspension-sissybar---raw-metal.html
But I'll have to build it myself since I didn't find any compatible with the wide of the back wheel.

Anyway, it is ready to be road tested, just waiting for the (I hope) last snow storm of the winter to pass (I'm located in Massachusetts) to give her a spin!

 

[dmopedMA]

I'm back,

Finally some "good" weather over the past weekends, I did few test rides and since I was using a 36T sprocket, it was to fast (I didn't get to the top speed) but not quick at all... since I had a 48T around, I tried it yesterday and that one is too big, very quick, but max speed of around 20mph... I just ordered the one in the middle 40T, let's see next weekend how it goes.

I fixed the issue of bending the exhaust, just using flexible exhaust pipe (https://www.ebay.com/itm/111999638791), cutting the original pipe to get the connection to the engine and the muffler and wrapping it with exhaust tape.

Still some work to do on it, but here is a cool picture a friend took of the bike:

 

[dmopedMA]

More updates: 40T with 9T pulley it's the sweet spot (ate least for me and now) good response in low rpms and max speed of 28-30mph [edit] 26-28mph [edit], cruising at 25 mph is smooth and nice.

I'm really happy of how she rides, when the motor goes to fool throttle, I feel like it vibrates too much, I have to spend more time to see if I need to tight the nuts to the frame or it is the muffler...

I rode it for around 1 hour in two 30 minutes ride this weekend, still some adjust to do:
- Find vibration on high rpms.
- Brakes (front is not bad, back is horrible) both to be improved.
- Gas tank, I got an idea from @KCvale to mount it screwed to the top of the frame, will allow me to move it forward (http://kcsbikes.com/topic.asp?TOPIC_ID=804).
- Front fender needs to be installed

Improvements on the To-Do list:
- Moving seat backwards and adding suspension on it
- Lights
- Painting the red part of the motor in black (not an improvement, but I need to spend time on it)
- Kill switch with key

 

[Hunter127]

"Extendo click."

So I wanna put a 4 stroke on a shwinn stingray chopper but the cranks and chain will get in the way can I run the bike without the chain and cranks and just have it powered by the engine would that be able to function correctly ,Hunter

 

[dmopedMA]

So I wanna put a 4 stroke on a shwinn stingray chopper but the cranks and chain will get in the way can I run the bike without the chain and cranks and just have it powered by the engine would that be able to function correctly ,Hunter

Why to read if I can just write?

 

[Frankenstein]

Why to read if I can just write?

f***, you don't even have to read you got like 6 or 7 pictures AND A VIDEO OF THE DAMN THING! Exactly why I didn't respond to his stupidness, thankfully you did so I could point it out.