Motorcycle sales, January-to-June 2020

OK. Let me tie this together. Things that will probably not happen again ... 1960's motorcycle/ scooter craze, catalog mail order guns, motorcycles, etc ... 🤔 ... unless the internet is the new Sears catalogs ...

The mauser reminded me of Sears catalog guns and my Sears motorcycle. Again, things that are probably not coming back.


1600103080034.jpeg

In the mid 60's, I got a neglected non-running Allstate SR250. An odd creature made in Austria. It was a two piston, two cylinder, two exhausts, one combustion head, one spark plug, two cycle powered. I got some cheap replacement parts from Sears and got it running. Shortly thereafter, someone offered me far more than what I had in it. Mine was dark blue.
1600103583534.png
 
The engine powering the SR250 is often called a "Twingle."

Coaster - I was only making a joke about about the thread! :)
 
I'm guessing that to have a two-cycle engine with two pistons/cylinders sharing one combustion chamber, both pistons must have moved together, and fired together. And then I wonder why bother with two pistons/cylinders? What are the advantages of that? Why not just one bigger cylinder?

Puch made these for Sears. When we lived in California in the '78-'79, we bought my daughter a Sears bicycle, made by Puch in Austria. She was in the 5th grade and was 4'11". The bike was too tall for her but the salesman said, "Oh, she'll grow into it within 6 months!" She really wanted the bike so we got it. She's 52 yrs old now and she's still 4'11". When I started riding bicycles in '86, I started on Labor Day on that old Sears bike and rode it for about 2,000 miles before upgrading to a Fuji the day after Thanksgiving that fall. I rode bicycles for just a bit over 30,000 miles and hope to get back on the one I bought when I moved here in '15. Since my 6th knee replacement that hasn't worked yet.
 
I'm guessing that to have a two-cycle engine with two pistons/cylinders sharing one combustion chamber, both pistons must have moved together, and fired together. And then I wonder why bother with two pistons/cylinders? What are the advantages of that? Why not just one bigger cylinder?

There are lots of reasons for this. Take your pick:
1. Puch was still figuring it out. Come to think of it we are still figuring it out. There are singles; twins, parallels, V; triples; 4 cyl's, inline, V; 6 cyl's. So what is best? Depends who you ask. The twingle didn't catch on that well so not sure about it.
2. Bragging rights. " This bike has so much power they had to separate it into 2 cylinders"
3. The differences make it fun. It makes the world go round.
4. Make up your own reason, it will be as good as any other.

Brad
 
Why the "twingle"? Perhaps, redundency? If you have two siamesed combustion chambers, with two sparks, four valves...having ONE plug foul or ONE valve out of adjustment, ONE set of bad rings, will cripple the engine, but maybe not make it quit

The Allstate bikes (mfg by Puch) were 2-strokes. I'm not sure what redundancy that leaves, except for spark plugs. But I'm not an engineer either...not even a choo-choo engineer. 🤪
 
As a general rule, a big combustion chamber is also a hinderence to good power per cc from 4-strokes such as large singles.
 
Last edited:
Back
Top Bottom