Where did my other two cc's go?

[Mag7C]

I've noticed motorcycles are always 1 or 2 cc's short. My 700 is actually 698, most 250's are really 249 or 248, etc. Never thought about it until now. Why is this?

[Gadjet]

you think that's strange?

My 650 is actually 673cc

[rapidblue]

i think it is just to make the naem sound more appealing and easy to remember

like say a virago 1100 sounds better than a virago 1063, not quite the same ring to it

plus then if one bike was 639cc and another was a 648cc, youde be more inclined to pick the 648cc because it was bigger (ever though theyre basically the same) so if they label them both as 650s then they can judged based on other more imprtant features

[iwannadie]

i thought it was for insurance reasons. you buy a '600' sport bike but really its 598 or whatever to get you under the 600cc bracket for insurance. when you get insurance on your '600' bike you can say its under and not '600 and up'. but most people probally dont know this and say they have a 600cc bike when its really 598cc.

[Nibblet99]

Actually it's for legal reasons. Over here in the UK, road tax is based on the capacity of your engine. So the manufacturers always leave you a couple of cc, incase you need to rebore the cylinder. That way you don't jump up a tax bracket.

[CentralOzzy]

Ducati seem very specific on their engine sizes eh High_Side?

How is your WIFE'S bike going?

[Mer]

I have a 1300, but in reality it is 1312. I guess it's just easier to round up or down a bit.

[Sev]

Probably the same idea as a bakers dozen. A bakers dozen is 13 buns or pastries.

This came about in England as a result of bakers shorting their customers by making the smallest possible buns, but charging by the amount sold. Not the weight. A law was passed that every dozen sold me but AT LEAST that weight, or the baker would loose his hands (I think that's the penalty). So to make sure they got to keep their hands it became a common practise to throw in an extra bun.

The same idea fits (for the most part) in reverse. If you want to race a 600cc bike you need to be at or under 600cc. 600.01 is not acceptable, so you make an engine that is actually 599cc and then race it in the 600 races.

That extra 1 cc makes no real difference in the bike.

[Randy]

I just sold my Virago XV920, everyone asked how many cc's it was. It was kinda funny at first, I guess everyone is used to round numbers.

[High_Side]

Ducati seem very specific on their engine sizes eh High_Side?

I dunno about specific, my WIFE'S monster 800 is actually an 803cc bike. It's doing well, although it is currently in for the first service and ahem, polution equiptment removal.....