Rotary experts...fill me in on this:

Why are there no rotary motorcycles.

It would seem to make sense to but the rotary technology into a sport bike: small space, high revving, lightweight, great power/liter ratio...

Maybe this has already been done and I'm just not aware of it. Anybody want to clue me in?

Yours truly...
Rotary Amateur...
chikai

Originally posted by chikai
Maybe this has already been done and I'm just not aware of it.Suzuki made a Rotary bike in 1975-77 - the RE-5. More recently, Norton made several in the 80's. More info here (http://www.monito.com/wankel/motorcycles.html).

Don't forget the Hercules W-2000.

felix wankel's research was primarily funded by NSU a motorcycle company, there are many rotary motorcycles, i just don't know if they are still in production

So if the axis of rotation of the rotors are perpendicular to the direction of the bike's motion, will the rotational inertia of the rotors affect the ability of the bike to lean? Making it more difficult to lay down?

http://www.rx7club.com/forum/attachment.php?s=&postid=1934046

http://www.rx7club.com/forum/showthread.php?s=&threadid=202682&highlight=rotary+motorcycle

:)

yeah Norton used rotors in their motors.

Boozehound quoted:
So if the axis of rotation of the rotors are perpendicular to the direction of the bike's motion, will the rotational inertia of the rotors affect the ability of the bike to lean? Making it more difficult to lay down?

Naw...even though power is being created by the motor, the rotational inertia and change in moment, while increasing or decreasing in speed of the motor, would cause minimal torque (making the bike lean) since the rotors are so small in comparison to the rest of the weight of the bike IMO.

Originally posted by QuantumTheory08
Boozehound quoted:


Naw...even though power is being created by the motor, the rotational inertia and change in moment, while increasing or decreasing in speed of the motor, would cause minimal torque (making the bike lean) since the rotors are so small in comparison to the rest of the weight of the bike IMO.
Quantum is right. Note that most motorcycles with shaft drive have their engines mounted longitudinally, while chain drive and belt drive bikes have their engines mounted transversely. You can do the same with a rotary engine and not affect handling at all.

Originally posted by Boozehound
So if the axis of rotation of the rotors are perpendicular to the direction of the bike's motion, will the rotational inertia of the rotors affect the ability of the bike to lean? Making it more difficult to lay down? I'm quoting Boozehound again so y'all can read it again. Axis of rotation of the rotors perpendicular to the direction of the bike's motion = plane of rotation of the rotors are parallel to the direction of the bike's motion, like that of a belt or chain drive.
I think he's talking about maybe a gyroscopic effect, with resultant forces acting to keep the bike from leaning? Piston engines don't have that possible effect.
I would have to yank out my textbooks again here to figure that one out. Anybody else have that answer? Are we on the same sheet of music now?

We have a winner! I was talking about a gyroscopic effect that having two big masses rotating at speed would create. Same effect having really big wheels on a motorcycle would have - hard to lean down when wheels are at speed.

Originally posted by Racer X-8
I'm quoting Boozehound again so y'all can read it again. Axis of rotation of the rotors perpendicular to the direction of the bike's motion = plane of rotation of the rotors are parallel to the direction of the bike's motion, like that of a belt or chain drive.
I think he's talking about maybe a gyroscopic effect, with resultant forces acting to keep the bike from leaning? Piston engines don't have that possible effect.
I would have to yank out my textbooks again here to figure that one out. Anybody else have that answer? Are we on the same sheet of music now?

Actually, transversely mounted piston engines DO have that affect, because of the crank shaft counter-weights and the flywheel.

Those objects rotating on an axis perpendicular to the length of the motorcycle generate a gyroscopic effect, just as the wheels do, which keeps the bike upright.

But the wheels have a MUCH greater affect than the engine internals ever could because of their dimmensions and weight.

Besides, you COULD mount a rotary engine longitudinally in a motorcycle. Nothing says you can't do that. Piston engines are mounted in both longitudinal and transverse directions in motorcycles, so why not rotaries?

Finally, the proof is in the fact that Norton rotary motorcycles handled just fine compared to motorcycles of their time. In fact, Norton won the Isle of Man TT with a rotary motorcycle.

Originally posted by Boozehound
We have a winner! I was talking about a gyroscopic effect that having two big masses rotating at speed would create. Same effect having really big wheels on a motorcycle would have - hard to lean down when wheels are at speed. Trying to answer your question here, I'm just gonna give my educated guess. Since you're only asking about the gyroscopic effect - if any - of the two spinning rotors, leaving all other considerations out of it - which is a good thing to do here...

The rotors, although they are similar to the mass of the two wheels, their mass moment of inertia, which is the main factor in producing a gyroscopis effect, is much much less. Their contribution would be smaller, and in addition to, the gyroscopic effect (mass moment of inertia) of the crank & flywheel).
So, I'm going to guess that, althouth there is some, the effect is negligible, to the point where an experienced rider will be able to instinctively correct for it, if it is felt by the rider at all.

I would imagine that with the heat the rotary puts out, combined with the radiator AND oil coolers you have to have, it would make things difficult.

---jps

this is kind of off topic but...how do you pronounce "wankel"? do you say it with a v instead of a w? because if it is infact the w, then it sounds pretty dirty. like "i'll put my felix wankel in your bum if you don't shut up" or something like that. and i have this article that has this section entitled "wankel ups and downs"

Pretty much all water cooled motorcycles have radiators and oil coolers. And motorcycle engines have MUCH higher specific output than car engines, so they generate more heat for their size.

Example...

The Suzuki GSX-R1000 has a 988cc engine that puts out roughly 165hp at the crank. That's a specific output of

167 HP/L

Much higher than any car, except the RX-8. If Suzuki and other motorcycle manufacturers can figure out how to cool such fire-breathing beasts, I'm sure they can figure out how to cool a rotary motorcycle.

Besides, like I stated before, Norton was quite successful with their rotary motorcycle. Unfortunately, the British hadn't learned the meaning of quality control yet.

I owned one of the Suzuki RE-5 roatary bikes - a truly awful motorcycle. It used lots of oil, had a voracious appetite for spark plugs (only one plug so you ALWAYS carried spares), and had an obnoxiously loud exhaust (not as bad as the 2 wheeled tractors - AKA Harleys). It actually would shoot flames out the exhaust pipes at times - quite a show at night.

Plus there was little dealer support and no one else could even begin to work on them. I had the engine replaced under warranty and nothing improved.

The bike had good torque, but was not that fast. It was generally smooth but a bit lumpy at low RPM. I had the first year model which had the "Buck Rogers" instrument styling. One thing the bike did do well was get attention.

I traded it in after one year for 50% of what I paid for it. Now, I understand, it is somewhat of a collector's item and may be worth a bit more.

On a different subject, I am STILL waiting for my yellow RX-8 and have been told it will be another month. What a total bummer!:mad:

Originally posted by mysterygrrl
this is kind of off topic but...how do you pronounce "wankel"? do you say it with a v instead of a w? because if it is infact the w, then it sounds pretty dirty. like "i'll put my felix wankel in your bum if you don't shut up" or something like that. and i have this article that has this section entitled "wankel ups and downs" Yes MG, it is pronounced with a "w", and seeing we're talking motorcycles, I could come up with a few pretty good one-liners here. But I'll let those pistonic types have at it.;)

Originally posted by Schneegz
Pretty much all water cooled motorcycles have radiators and oil coolers. And motorcycle engines have MUCH higher specific output than car engines, so they generate more heat for their size... I realized that motorcycle engines have much higher specific output, but I didn't reallize that they had big oil coolers too. Interesting.

---jps