Total Motorcycle Community Forums

I was watching the AMA race yesterday and the commentater made the comment that the Ducati 999F had a higher top speed than any of the I-4 bikes. Did he mean just for a particular lap or does it actually have a higher top speed? I thought this was odd since I-4's are known for going fast in a straight away and V-twin's are known for eating up the twisties...

I may be wrong but I think you have this backwards. I think the v-twin has a higher top speed and the inline-4 has the twisty thing.

No, he was right, V-twins are better for twisties because they make more usable torque at lower RPMs, which is used to catapault them out of corners with greater ease.

I-4's are normally designed for more peak horsepower, resulting in higher top speed.

I have no idea what the commentator meant, and I do not know the top speed of the Ducati 999F. I would assume he meant the top speed for the track, but I could be wrong.

I was under the impression that the crouch rockets were all I-4's or V-4's to do the twistie thing. I ride a V-2 and I believed that the I-4 were quicker at the start but did not reach as high a speed as the V-2. Good info to know.

Wild guess......

The Duc engine can be made to deliver more power at lower RPM(torque) and can use that to get out of corners faster than a I4 typically can. If the Duc has enough extra snort at lower RPM, you can sacrifice some of that torque and run higher gear ratios on the final drive. Done right, you can keep your advantage in corner exists slightly and have more gear on top, allowing you higher top speed as well.

This suposes that the Duc has enough advantage down low to pull this off, and that some team running a 4 hole hasn't tuned thier engine for low end and is trying the same gearing game. Don't forget, an I4 can be made to produce an impressive torque surge as well, with plenty left over for top-end screaming to boot. Ask any Big Bandit or ZRX rider.