Why do sport bikes generally come in more sizes than cruisers?

I notice sport bikes you can usually find a 250, 500, 600, 750, 900, 1000, 1100, 1300, 1500. Cruisers generally seem to be 600, 1100, and like 1400. I know now they are comming out with 1800's and stuff like that but how come sport bikes come with many more sizes of engines?

there are a ton of cruisers that come in different size engines look at the star line of cruisers

I can't believe nobody's answered this in a whole hour. So I'll try.

Sport bikes, I mean real sport bikes, not just 'sporty' styled bikes, are based on racing categories. Motorcycle racing categories go down to 50cc, but in the US nobody want a bike that small, so 250 is as low as they go. And the other categories are basically as you have them laid out--250, 500, 600, etc. The largest class is 'open' which I believe is around 1000cc, there's not much need to go higher. For street-legal sport bikes, each of these sizes has its advantages and disadvantages. But remember also that many people buy street-legal sport bikes to race at the track.

The concept of cruisers, though, is that they're big bikes to begin with. The standard for cruisers forever has been Harley Davidson. Their standard size for years and years was 1200cc. They made a smaller bike, the Sportster, which was 980cc, but wasn't a cruiser. In the 1960s/1970s, those two models of Harley were the biggest sizes of motorcycles available. Everything else was mostly 650-750 with a few 1000cc sportbikes that were considered exotic, only for the real enthusiast.

When the Japanese began making cruisers they were 750s, they were variations of their regular all-purpose bikes, only with a 'cruiser' style. But in the last few years, both the Japanese mfgrs and Harley have made bikes bigger and bigger. It's almost like bigger is better. 1400cc for a two-cylinder motorcycle is kind of crazy. 1800cc is -really- crazy.

There are still some cruiser-styled bikes that are as small as 500cc, but they are seen as toys, as starter bikes. REAL cruisers are all over 1000cc these days, so there's no point in making them 250, 500, 600 etc.

That guy said it all. I'll just add that the inefficient v-twin at 500 or in the case of the harley 883cc doesn't have the get up and go of a 250 ninja.

Crusiers really are the worst class of bike.

Like SID said, there are just as many different sizes of cruisers. 250, 500, 600, 650, 750, 800, 900, 1000, 1100, 1300, etc.