Rotary Pics

The "Rotary" Motor

Is not a Wankel or true rotary, as you noted, but cylinders are opposed like VW, Porshe, Subaru engines.

I suppose the rotary part comes from the crankshaft rotation from fore and aft pistons powering or rotating the shaft/flywheel. Me not engine tech, so just guessing from diagrams.

They are spendy, however, and quite heavy. Kit is 30 lbs.

Top end seems to translate to about 25 MPH, which is fast enough for me.

True free wheeling is important concern, as is light weight for normal biking for this dodger.

With the engine down along frame, idea offers great space use over rear wheel and on starboard side for shoppers and commuters.

Thinking one of the gas tanks to replace engine mounted versions and set it right behind seat for more capacity on longer trips might work well.

Changing rear tire may be a hassle, perchance a flat befalls rider.

Still, another quality option from down-unda ...
 
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Is not a Wankel or true rotary, as you noted, but cylinders are opposed like VW, Porshe, Subaru engines.

I suppose the rotary part comes from the crankshaft rotation from fore and aft pistons powering or rotating the shaft/flywheel. Me not engine tech, so just guessing from diagrams.

The Sachs and the Chinese Rotary brand copy are one cylinder, 2-stroke engines. The cylinder is on its side, cylinder head/spark plug pointing toward the front of the bike. It is not an opposed engine (ie BMW motorcycle) as there's no other cylinder to oppose. There's only one.

"Rotary" in this case is simply a brand name. It has nothing to do with the engine's design or operation.
 
No Doubt

Yes, thanks, Weez.

The comments referenced the "Rotary" engine made and sold in Australia, shown below.

Again, not a Wankel, but likely refers to the rotary crank between its opposed cylinders.

I have a Sachs and understand these moped engines are single cylinder putters.

See the link for "Rotary" engine below...

http://www.rotarybike.com/rotarybike_products.asp?type=Petrol
 
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The 'Rotary' branded engine is a Sachs design, made under licence in China.

Again, not a Wankel, but likely refers to the rotary crank between its opposed cylinders.

Both the Sachs and the Rotary branded copy are single cylinder, not twin cylinder engines. Only one cylinder! Not 'opposed'- there's no other cylinder to be opposed!

The choice of brand name surely introduced some confusion for the Chinese 'Rotary' company, but their Sachs licenced motor has nothing at all to do with rotary engines of any kind, not radial piston nor Wankel engines. 'Rotary' in this case is nothing more than a brand name.

Once again, the Sachs and the Rotary brand copy are ordinary ONE cylinder 2-stroke engines, with ordinary crankshafts... which rotate... like all crankshafts do.

Rotary's website shows an exploded diagram of their bike engine. You will note it has but one lonely cylinder!
 
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I Am Not Proficient



In such matters, but this link suggests otherwise.

http://www.rotarybike.com/rotarybike_content.asp?pid=1

Moreover, one store down there (Australia) and one vendor in Florida no longer carries Sachs - as not being available.

The Rotary is not a single, and looks well machined, as noted also by its hefty price, compared to the Peoples Republic (funny one) motor.

Like, it makes a difference to we Yanks, who likely will not give up the suds to buy one.

My Sachs is German, all the way, meinen comarade!


Perhaps someone can clarify?


 
One could be excused for thinking that these Rotary engines are Australian made. From the Rotary Australia website:

More production is performed 'in house' than any other power assisted bicycle supplier in Australia. In the case of our RH-01 power unit, only component manufacture is sourced outside Australia. All engines are proudly assembled with AUSTRALIAN labour & subject to a strict QC process before final fitment to products.

We take pride that in this market of cheap imports, we can supply a locally produced product that has many hours of in-house R & D with key features being compliance, reliablity & future serviceabilty.

This sort of statement borders upon outright deception.

Rotary is buying in completely assembled engine kits (to these folks, that kit is a 'component') made in China and bolting them on to ready-made (also very likely Chinese) bikes- in Australia.

This is a bit like saying my glass of juice made from oranges grown in California is 'Australian made' because my juicer is in a kitchen located in the Blue Mountains of NSW.

Rotary Bikes Australia are trying to give the impression through their statement that their engines are made in Australia- and quite simply, they would not earn the 'Australian Made' tickmark. Here's the Australian Made Code of Practice.
 
It All

Makes perfect sense to moi!

I must have been looking at another engine which seemed to show twin wires to plugs. Why I figured they were so heavy.

Ah, how sooo, I see one of the pics I have is wrong way-round and not from rear. Ah soooo!

Slow speeds make more sense too.

We learn everyday, mate!

Merci!



 
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