600? 750? 900? 1000? 1100?

[andyb]

Here's a question for you old bastards gentlemen of extensive first-hand experience with history.

Why 600cc bikes?  Back in the early 80's, you could get basically anything you wanted.  Look at the GS and CB lines for example, from the top of my head I can think of a 250, 350, 360, 400, 450, 500, 550, 600, 700, 750, 850, 900, 1000, 1050, 1100, 1150.  That's a lotta different motors!  I realize that the GS line in particular is very mix and match, and there aren't as many bespoke parts as you'd think (everything interchanges pretty well).

In 85 or so, the GSXR750 came out.  Superbike racing at the time was 750cc for a I4 or 1000cc for a twin.  Okay, makes sense.  It's a great size for a streetbike, it's a good size for a racebike.  Plenty of power, not overwhelmingly heavy, and still enough grunt to be usable without forcing you to pin the gas constantly.  Cool. 

The 900/1000/1100 machines I think were simply as big as anyone imagined would be usable and safe at the time.  As the power goes up, the frame gets heavier, and the market for a 1800cc I4 that weighed 1300lbs dry was limited in the sporting arena.  I get that.  The ZX9R was a sport machine, the ZX11 was a more touring bike... the weight being much of the difference.  That, and the 900 was essentially a biggy-sized 750, whereas the 11 was initially planned as a sporting bike, rather than a sportbike.  All makes sense to me.

But then there's the 600.  Why? Why was a size only 150cc smaller than their superbike offerings chosen, rather than a 500?  Yamaha had the FZR400 for a brief stint, didn't sell so well.  Would 500cc machines have also done so poorly?  The 600's are certainly popular, and were then as well.

Some of the sizes were because of things you wouldn't think of today.  Reagan's >750cc tariff in the mid 80's meant that there's a bunch of 700cc models, such as my 87 SuperMagna (still for sale, incidentally!) that in 1988 became a full 750, as the huge tax had lapsed by then.  But the 600's make just no sense to me at all.

While I'm at it, does anyone else wonder why the CBR900RR wasn't simply destroked and sold as a 750?  Honda desperately needed help in that department at the time, as the RC30/RC45 were horribly expensive and didn't sell to street riders, so Honda was left without any representation in that portion of the market.  And then the 900 has a suspiciously long stroke... it's almost as if they realized that they were too down on power in 750 guise and stretched it a bit later just to throw it into a class alone--in 93, it weighed the same as the 600's, and the competition were all very heavy (GSXR1100, ZX11, ZX9R, FZR1000).  Just a hmmm thing there.

[FJmonkey]

Throwing my hat into this ring...I am guesstimating it is from how insurances were rating bikes. Evey so-many years they would reclassify what a big bike bike was (or a risky engine size, statistics might of have had some influence) and have different rates. It encourages the sellers of these bikes to change the size just enough to maximize the engine size and fill a niche market. My second opinion is Sun spots....That's all I got. Regular programming is back to you.