HS 142-F reverse engine and SBP freewheel brainstorming...

[Frankenstein]

Not enough engagement, I think. As Pablo said to a similar idea earlier in the thread.

I'm wondering why (or if!) a four stroke engine can't be made to run in reverse anyway? I mean apart from things loosening.

 

[gary55]

Build something similar to the belt drive. Directly engage gears instead of belts and pulleys to rev. rotation. Come off the big gear with a sprocket, and chain down to the free wheel bottom bracket sprockets. A slightly more involved trans. but no j shaft. Should save costs in the long run. With a good cent. clutch it would go well. With a manual clutch it would be awesome. Their is a crude concept of what you have to build to slap onto the side of a right drive 4 stroker sitting under the clutch cover of the china girl.

 

[5-7HEAVEN]

Many years ago, a fella succeeded in doing that with a 6hp Robin engine, mounted mid-frame in a bicycle. He either posted it here or in "the other forum".

Unsure if he used sprockets or pulleys. He placed a pulley/sprocket ABOVE the engine pulley/sprocket, SERPENTINE-style.

To ensure sufficient engagement, you could install TWO sprockets/pulleys above and astride the engine sprocket/pulley.

 

[bakaneko]

Many years ago, a fella succeeded in doing that with a 6hp Robin engine, mounted mid-frame in a bicycle. He either posted it here or in "the other forum".

Unsure if he used sprockets or pulleys. He placed a pulley/sprocket ABOVE the engine pulley/sprocket, SERPENTINE-style.

To ensure sufficient engagement, you could install TWO sprockets/pulleys above and astride the engine sprocket/pulley.

Hmm, I found this in the annals the rider reversed his engine to fit it into the smaller frame and not to utilized a SBP freewheel to use the right drive train. But, the placement of the roller is smart. I reversed my HS-142F engine with a normal transmission just to test and there is not enough clearance to directly engage the transmission sprocket for a reverse rotation and I thought other points on the bike too weak to handle the torque of the engine, but this placement seems like a good strong area (lotsa points for securing, seat tube, top tube junction) to be the focal point of the rotation reversal. Thx for bringing that up.

 

[KCvale]

View attachment 76076

Well there ya have it...
More examples of how NOT to get engine power to the right to use the bikes gears.

 

[Frankenstein]

Well there ya have it...
More examples of how NOT to get engine power to the right to use the bikes gears.

Other than the lack of gear down the design is awful. I mean awfully good. Not really...

He asked how to flip is and connect the motor to the rear wheel, did exactly that and nothing else. I'll note your photographs weren't much better, they all had the driveshaft on the left side!

 

[Frankenstein]

Hmm, I found this in the annals the rider reversed his engine to fit it into the smaller frame and not to utilized a SBP freewheel to use the right drive train. But, the placement of the roller is smart. I reversed my HS-142F engine with a normal transmission just to test and there is not enough clearance to directly engage the transmission sprocket for a reverse rotation and I thought other points on the bike too weak to handle the torque of the engine, but this placement seems like a good strong area (lotsa points for securing, seat tube, top tube junction) to be the focal point of the rotation reversal. Thx for bringing that up.

That looks cool, so I must ask how easy is it to just reverse a 4 strokes rotation? Way too easy on the universal 2 stroke but seems like it would be harder on one of those to a certain extent. Or would it... Is it all just in the spark timing I mean it's doing the same exact thing only spinning a different direction..

 

[gary55]

Turn the seat around and steer from behind.

 

[CrazyDan]

That looks cool, so I must ask how easy is it to just reverse a 4 strokes rotation? Way too easy on the universal 2 stroke but seems like it would be harder on one of those to a certain extent. Or would it... Is it all just in the spark timing I mean it's doing the same exact thing only spinning a different direction..

I'm pretty sure the engine is beefed up in a way to handle the rotational stresses in one direction but not the other. You'll probably see failures at multiple points. Think about how many nuts/bolts are threaded so they tighten with regular usage but unscrew themselves if reversed. You'll have to reverse thread many things.

 

[Steve Best]

That looks cool, so I must ask how easy is it to just reverse a 4 strokes rotation? Way too easy on the universal 2 stroke but seems like it would be harder on one of those to a certain extent. Or would it... Is it all just in the spark timing I mean it's doing the same exact thing only spinning a different direction..

The spark timing, cam lob order/timing and any oil pumps or directionally oriented oil dippers/slingers/scrapers/baffles need to be changed. Timing is typically easy with a new flywheel keyway. The cam needs to be cut and rewelded (typically drilled for an alignment shaft) to reverse the order of the lobes and then retimed. Splash lubricated engines may need some thought where direction often determines top end lubrication, but most just rely on splash and mist so you may be OK.