[B]why haven't the 2 stroke kit designers thought of this?[/B]

x-soldat

New Member
Jan 26, 2009
14
0
0
Eschenbach, Germany
Was looking at my bike engine today and a thought hit me...If you simply turn the engine around (carb facing front wheel/exhaust manifold facing the rear) it would place the drive gear on the right side...This would allow you to run a freewheel system similar to the one available at SBP without the need for a jack shaft kit...obviously there are some engineering challenges, i.e. mounting hardware and exhaust, but it doesn't seem to be that hard to fix...also the innards would need to be re engineered so that you aren't doing 30mph in reverse...lol...Even if it was to be used on a single speed bike it would still solve problems, such as eliminating the need for a rag mount sprocket, having wheels that stay trued would fix allot of the noticeable vibration...WTF?
 
Last edited:

2door

Moderator
Staff member
Sep 15, 2008
16,332
137
63
Littleton, Colorado
The issue is timing, to make the engine run in reverse. I'm not certain what all is involved but there have been discussions here about reversing the rotation of the China 2 stroke engines. Maybe someone here with more engine experience can shed some light on this for you. I can see where mounting could offer some challenges but the exhaust would not be difficult. Everything else should hook up without much effort. Keep us posted if you try your idea.
Tom
 

georgeknight

New Member
Sep 26, 2008
34
0
0
64
Lebanon, Mo.
Was looking at my bike engine today and a thought hit me...If you simply turn the engine around (carb facing front wheel/exhaust manifold facing the rear) it would place the drive gear on the right side...This would allow you to run a freewheel system similar to the one available at SBP without the need for a jack shaft kit...obviously there are some engineering challenges, i.e. mounting hardware and exhaust, but it doesn't seem to be that hard to fix...also the innards would need to be re engineered so that you aren't doing 30mph in reverse...lol...Even if it was to be used on a single speed bike it would still solve problems, such as eliminating the need for a rag mount sprocket, having wheels that stay trued would fix allot of the noticeable vibration...WTF?
If you turn the motor around, that would make the sprockets run in reverse.
 

x-soldat

New Member
Jan 26, 2009
14
0
0
Eschenbach, Germany
If you turn the motor around, that would make the sprockets run in reverse.
Thanks, I realize that... I stated it in the original post...If that wasn't the case I would have already flipped the motor....I'm just hoping a manufacture reads the thread and sees a demand for this type of kit...Scott
 

jasonh

New Member
Jun 23, 2008
1,590
0
0
36
Longmont, CO
Timing would probably just be a matter of reversing the magnet in the magneto.

If you turn the whole motor around, the drive sprocket will be at the front of the motor, not that back. that's the real issue.
 

HoughMade

New Member
Apr 15, 2008
624
1
0
Valparaiso, IN
I agree that the idea has potential.

My guess would be that with the goal being cheap....CHEAP...it is cheaper and easier to provide 9 bolts, 2 hunks of rubber and a sprocket than to provide a front free wheel, plus that way fits more bikes. Also, you can't have a front derraileur. One last thing, the jackshaft in the SBP provides additional reduction because the standard gears on the rear of a bike all have less teeth than a typical driven sprocket. More reduction than the engine normally has is necessary before you can just drive the standard gears.

However, it can be done.
 

ebmvegan

New Member
Jul 15, 2008
283
0
0
OC, Ca
I agree with Hugh. It comes down to economics. It's an old design and it works. Changing it takes money. X's thought may have already been done, but not marketed because of cost maybe.
 
Sep 20, 2008
1,668
2
0
Clearwater, FL
web.tampabay.rr.com
I agree with Hugh. It comes down to economics. It's an old design and it works. Changing it takes money. X's thought may have already been done, but not marketed because of cost maybe.
To really make this work the transmission items that make up this engine would have to be mirrored and modified slightly.

The clutch would have to be on the left side, the Mag and drive sprocket on the right. In other words a totally different engine.

The only thing required to make the engine run in the opposite direction:

Re-broach the magnet. That's all! 30 minutes tops.

I could see this working for one of the crank forward type bikes, like the OCC Schwinn, or the Spoiler, or the Jesse James, or any other crank forward bike that you guys know of.

The amount of work required to make it work for a conventional bike would likely negate the benefit. Reverse the engine in the frame of most bikes, and the angle of the chain would be so drastic, (sprocket back to pedal crank), that it would not even come close to clearing the engine case.

Jim
 
Last edited: