A motorcycle question.

"The Transporter" (transporter) 04/28/2014 at 22:23 • Filed to: None

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So I know why Wankel rotaries never really caught on with cars, but why didn't they with motorcycles? The lack of torque with rotaries really doesn't mean that much for a few hundred pound motor cycle, and even though rotaries consume fuel like they were made by OPEC, on a motorcycle it should still be about as fuel efficient as a Prius, plus the high revs should have caught on with the sport bike crowd. I know that a German company tried it in the '70s, but after a few thousand production models, that seemed to be it. So what happened?

PheeNoIVI > The Transporter 04/28/2014 at 22:24

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I have no idea. But they don't look at good I know that

doodon2whls > The Transporter 04/28/2014 at 22:29

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I think it has to do with reliability, efficiency, and emissions at smaller wankel displacements. It is hard enough to make a 1.3L rotary pass emissions or achieve good fuel economy - ask Mazda. Now consider a displacement 1/4 (or less) than that in a motorcycle - the cylinder blow-by and wear on the rotor have a larger effect w.r.t. the smaller displacement and output.

The Transporter > PheeNoIVI 04/28/2014 at 22:31

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I could think of a dozen different ways that I could mount it and make it look better. The only possible reason I could think of for mounting it that was was because ze Germans.

jariten1781 > The Transporter 04/28/2014 at 22:36

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They ran too hot. Apparently rotaries are a bitch to cool and even the exhaust gasses were so hot that they required special heavy shielded exhausts. They also required oil injection to cool the internals without a large radiator. It made them too heavy and complicated vs their piston competitors. Suzuki and some British companies (Norton?...don't remember) sold them for a few years in the 70s and they failed pretty miserably.

CRider > The Transporter 04/28/2014 at 22:37

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I'll add 'rotary motorcycle manufacturer' to my list of companies to start when I become a billionaire.

To answer your question, though, there are a few reasons the idea died out in bikes. Many of the same reasons they died in cars, they had little torque, guzzled fuel and had exhaust emissions that are bad by any standard. They also had some mechanical and cooling issues.

jariten1781 > PheeNoIVI 04/28/2014 at 22:47

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Suzuki's just looked like any other mid-70s standard.

beardsbynelly - Rikerbeard > The Transporter 04/28/2014 at 22:49

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The Nortons were relatively competitive in the late 80's and early 90's. They won the Isle of Mann TT and a bunch of other races in '92. The company had money issues and went through a few owners. Eventually the wankel engine side of it was re-purposed to build aircraft engines. the MidWest and Austro wankels are based on the Nortan twin rotor.

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Heat was an issue though, and they burnt through a lot of oil so they were never deemed reliable enough for mass production. The Norton F1 is damn cool though.

The Transporter > doodon2whls 04/28/2014 at 22:51

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The Shadow 200 UAV that I used to fly had a small 208 cc Wankel that could produce 38 hp, propel a 400 lb UAV through the air at 110 kts, and would be a perfect fit for a small CB 200 sized sport bike. Of course, it produces that 38 hp using 100LL avgas through a short straight pipe exhaust with no catalytic converter. They also had to be overhauled every 250 hours. Oh, and it was built by the Brits, i.e. the same country that spawned British Leyland and Lucas Electric, so build quality could be... fluid. I saw one engine failure in my 5 years of flying them, but that was due to a crank shaft bearing seizure, i.e. a supplier issue, and not a fundamental problem with the engine. Still, that's one more engine failure than I've seen in my longer career in manned aviation.

PheeNoIVI > jariten1781 04/28/2014 at 22:56

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It does lol. You win

toadterror > The Transporter 04/28/2014 at 23:31

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The N1 was awesome.

It's said to be a very hot ride because of all the enclosing plastic.

Satoshi "Zipang" Katsura > The Transporter 04/29/2014 at 00:06

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In my honest opinion, it's probably something to do with torque being the important factor. As you said - horsepower and torque wouldn't play a significant role in a motorcycle, but do you enjoy revving all the way to 10,000 RPM to actually see some morsel of power like most bikes?

The Transporter > Satoshi "Zipang" Katsura 04/29/2014 at 00:08

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Hayabusa owners apparently do.

Satoshi "Zipang" Katsura > The Transporter 04/29/2014 at 00:17

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.. Jesus, I would be terrified on riding anything with more than 230 HP.

Then again, I was told this bike would be an absolute riot - having so much power and torque that you'd have to change the rear tire so many times.

E92M3 > The Transporter 04/29/2014 at 09:01

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Norton and Suzuki both used a wankel in a motorcycle. Wankel had a patent on the engine, so they had to pay licensing to be able to use it. It probably wasn't worth the cost in the end when you consider the problems associated with them.