Most reliable style of motorcycle?

So I'm curious as to which style of bike is the most reliable. Cruiser, sports bike, dirt bike (street legal).

Not I can already hear the people saying there are too many factors involved to tell but I doubt that is true. Stats can be made for everything. But to simplify this let's take a brand that makes all 3, like honda. You get a cruiser, a sports bike, and a dirt bike all of equal displacement and brand new. You ride each 50 miles to work and back on 55mph back roads every day during summertime.

(All dealer recommended maintenance performed)

Which is most likely to kick the bucket first? And by kick the bucket I mean it will need major repairs. By major repair I mean it needs the engine to be opened or it needs expensive parts or else it will not run.

I don't see how a "style" would have any bearing on reliability.

Reliability is dependent on make, model and year.

You're missing the "standard" and "adventure" categories. I would go with either one of those. Relatively low rpm low vibration engines with robust crankshaft journals and pressure-fed shell bearings, like the BMW R-bikes, can go 200k miles before needing a complete engine teardown. But other moving parts, even driveshafts, can fail sooner. What's an "expensive part?" Alternator rotors don't usually go that far. A new rotor can run several hundred dollars. They're not hard to install, but if you're a mechanical dufus you might have to pay a shop $700. Is that an "expensive part?" You tell us. The Honda NC700X engine is based on an automobile engine and should be bulletproof. The Honda Africa Twin also.

Virtually any modern motorcycle from any of the major manufacturers will be very reliable. Just maintain it according to manufacturer specs and it should last a long time.

Maybe cruiser. Sport bike is tempting to do something silly on street. Dual sport tempts people to silly things in the dirt. Cruiser is comfortable get to work and weekend hiway rides, less likely to do silly things like try to outrun police. Second is engine tune- cruiser compared to same basic sports engine may have a lower compression ratio and milder cam timing for use with lower octane gasoline compared to 'sports' model. Dual sports engine may have mild tune as well, be reliable- but they often get dropped more than cruisers, some bits and pieces cracked then.

Tourer. Think about it--to be expected to do a cross country trip of 3,000miles, it would have to be reliable. And, liquid cooled.

"… Honda. You get a cruiser, a sports bike, and a dirt bike all of equal displacement and brand new. You ride each 50 miles to work and back on 55mph back roads… "

Reliable: same maintenance, same manufacturer/dealer. Brand new, equal displacement (close enough… )
2017 Honda Rebel 300, CBR®300R, CRF®250L -- *same* engine/ transmission, everything ('cept the dirt is shorter stroke.) The only difference is the style and the rider/owner and how abusive he/she is.

The style of the bike has nothing to do with its' reliability. If you use a dirt bike as a dirt bike it is likely to fall apart sooner than a cruiser you drive around town. Though there's a lot higher chance of the cruiser getting crushed by a car.

So, you're saying that the identical 1200cc boxer engine fitted to the BMW R-1200RS (sports), the BMW R-1200RT (tourer) and the BMW R-1200GS (adventure) will have different reliability characteristics, JUST because of the different STYLE of bike it's powering?

Really? So, how does the engine know to be more or less reliable, just because it's in a sports bike, rather than a tourer? You can see how daft your concept is, can't you?

In 33 years years of riding, I've never heard such ridiculous idea. Almost any modern motorcycle engine (no matter what STYLE of bike it's fitted in) can easily exceed 100,000 miles, before needing major work, if it's properly maintained.

The most reliable bikes are dual sport adventurers.

Stick to japanese brands. For almost 6 years in a row, the Consumer Reports study on motorcycle reliability has been won by japanese bikes. Actually, 6 times winner is Yamaha.

You look simply mahvelous dahling.