2

Can a higher cc (displacement) bike with 5 speed transmission or a lower cc (displacement) bike with 6 speed transmission have higher top speed?

Example: Yamaha R15 (150cc, 6-speed transmission) v/s TVS Apache RTR 200(200cc, 5-speed transmission)

Which one would be have a higher top speed?

  • 2
    I think this is too broad. – JoErNanO May 24 '16 at 18:51
  • 1
    As everyone else has said, there are a lot of different factors. NASCAR circle track racecars have 4 speed transmissions and routinely drive 200+ mph, the GMC Yukon Denali has an 8-speed transmission and tops out at 112 mph. – MooseLucifer May 24 '16 at 20:09
3

It depends

There are too many other variables such as:

  • Wind resistance at top speed of the vehicles

  • Loss of power through the various components from the engine to the rear wheel

  • Gear ratios

We can get some of this information, such as gear ratios, but the other components necessary are beyond our reach.

I don't believe your question can truly be answered.

3

The question as asked has no real answer, so let me explain a few topics that will point you in the right direction.

The number of gears has no effect on top speed. The ratio of each gear is the important part. You could conceivably have a 3-speed transmission with a higher top speed (for a given RPM) than a 7-speed transmission. Having more gears can give you better acceleration and handling because you can keep the engine in the "power band" more easily. Engines can have a narrow range (power band) where they make the most efficient power.

A larger engine could produce more power, and should have a higher top speed with all else being equal - however the gear ratios of their transmissions are almost certainly not going to be equal, so again, that's what we really need to know.

Since you are asking about two motorcycles with small engines, wind resistance will probably be the biggest factor in top speed. You're not going to make it to either vehicle's theoretical top speed (redline RPM * final gear ratio). The larger engine should be more powerful, and should allow you to eke out a higher speed, but this is just a guess. There's also many cases of a smaller engine having more power than a larger one, so that adds another wrinkle.

0

If you're only considering top speed and not acceleration then the number of gears don't matter. The only thing that matters for top speed is aerodynamics and the power to overcome wind resistance.

  • 1
    Power + gear ratio; you can't reach 100 mph in first gear. – MooseLucifer May 24 '16 at 20:31
  • You can reach 200mph in first gear if you have a tall enough gear and a powerful enough engine. Check out the Koenigsegg Regera; single-speed fixed gear for an extreme example. Definitely not practical though :) – skeng May 24 '16 at 20:38
  • 1
    Exactly, gear ratio is just as important. – MooseLucifer May 24 '16 at 20:40
  • As @MooseLucifer gearing is a huge factor. Look at 1/8 and 1/4 mile drag cars. You'll run out of gear in an 1/8 mile car if you try to run it on a 1/4 mile track, but you could have the same exact engine in it for this to happen. – Pᴀᴜʟsᴛᴇʀ2 May 24 '16 at 21:27

Not the answer you're looking for? Browse other questions tagged or ask your own question.