2 vs. 4 cylinder sportbikes

[kabob983]

Recently I went to a WERA endurance race and noticed something odd. All of the 4 cylinder bikes absolutely flew past the 2 cylinder bikes on the straightaways. (I'm assuming that each was 2 vs. 4 based on the sound they made, the deep, throaty 2 cyl vs. the whiny 4 cyl bikes). I don't mean just 1 guy on a Gixxer 1000 went past, but EVERY 4 cylinder bike went flying past. Is this a common thing? I see that most european bikes are 2 cylinder and people regard them so highly, it'd be odd to think that a much cheaper 4 cylinder japanese bike would be so much faster.

What is the advantage of each configuration? Was the faster 4 cylinder bikes more a result of rider skill (which seems unlikely).

[ZooTech]

The V-twins typically have more torque, making them better in the twisties (also attributable to the narrower engine). The 4-cylinder bikes make a lot more horsepower, but need the straights in order to get the RPM's up where the power is made. It's not uncommon for a 4-banger to put out triple-digit horsepower but only fifty some foot-pounds of torque. If you're interested in straight line speed, get a four banger. If you love the twisties and like being able to ride through them in a higher gear, get a twin.

[TechTMW]

All of the 4 cylinder bikes absolutely flew past the 2 cylinder bikes on the straightaways.

The straightaways were after the curves, where the twins took the lead right?

In addition to waht Zoo mentioned, another big advantage for twins is that they tend to be lighter...

Singles and twins are also more versatile - they are much better in the dirt for example. There's a reason why there aren't any 4-cyl offroad bikes or even adventure tourers for that matter.

[TechTMW]

Here's some more info for you. In case you still think twins are slow.

http://www.ducati.com/racing/home_news_ ... wsId=24036

http://blogs.motorbiker.org/blogs.nsf/d ... MWEFEZ.htm

Ducati didn't get their reputation by LOSING races ya know

[kabob983]

Actually, the race was completely dominated (in and out of curves as well) by a guy from Vesrah Suzuki...no one could touch him. The twin's didn't gain much (if anything at all) from the twisties as far as I could tell, but then again I was so transfixed by how fast Vesrah was going that I probably didn't notice.

[jmillheiser]

Rider skill has a lot to do with how fast you are in general on a track.

Sounds like the guy on the Suzuki was a damn good rider

[TechTMW]

Indeed. In the movie FASTER (Which you should go out and beg borrow or steal if you haven't seen it yet) they say that In bike racing, the rider is 80% of the equasion, the motorcycle is only 20%.

(As opposed to car racing, where the car is 80% of the equasion)

[Mintbread]

If you're interested in straight line speed, get a four banger. If you love the twisties and like being able to ride through them in a higher gear, get a twin.

Hahahahahaha.

The twins don't seem to be doing too well at MotoGP and World Superbike level. Maybe it is because there are no corners where they race?

That or fours are FASTER in the corners and the straights.

[DivideOverflow]

If you're interested in straight line speed, get a four banger. If you love the twisties and like being able to ride through them in a higher gear, get a twin.

Hahahahahaha.

The twins don't seem to be doing too well at MotoGP and World Superbike level. Maybe it is because there are no corners where they race?

That or fours are FASTER in the corners and the straights.

That is all a matter of the degree of the turn, and the length of the straights. If you get a similar sized V-twin engine on a bike, and make the bikes slow down significantly for a tight corner, the torque from the V-twin will allow it to accelerate faster out of that turn. However, the 4-bangers have have the advantage in top end, so they will be able to overtake them with long straights, or curves where they don't have to slow down much.
You are talking about specific track designs that work better for 4 cylinder bikes. If you look at the sheer mechanics of it Torque VS Horsepower, it is quite obvious where each one's strengths lie.

[High_Side]

Hahahahahaha.

The twins don't seem to be doing too well at MotoGP and World Superbike level. Maybe it is because there are no corners where they race?

That or fours are FASTER in the corners and the straights.

You could look at the 90s where 9/10 WSB titles were V twins...... I know that they had a displacement advantage but I am neglecting to mention that.....ooops! Did I say that out loud????