Quote:
Originally Posted by Darkness
The 0.3% improvement mentioned is solely due to the reduction in mass, a three hundredth of the weight of bike and rider. It completely ignores rotational effects.
https://en.m.wikipedia.org/wiki/Newton's_laws_of_motion
It should be possible for me to get my remaining brain cells to quantify the change, I was just hoping someone had already done it! |
Agreed, I'm sure the mathematics are a lot more involved than the single equation quoted in the article. Unfortunately, I've already used up my monthly quota of brain cells trying to get my head round vectors and trigonometry in Richard's thread!
Do we need to take into account the effect of gearing? Do you remember those thrust curve graphs that used to appear in owner's manuals to tell you when to change gear? (Showing my age there!) Here's an example:
There's an interesting article in this month's Bike magazine in which they use a thrust curve graph to show why the Triumph Speed Twin feels so good on the road. Thrust curves are calculated from the torque, gearing and wheel size and mirror the shape of the actual torque curve.
They show how the gearing magnifies the effect of the engine's torque at the rear wheel. For example, the Speed Twin produces 83 lb.ft torque and the maximum thrust at the rear wheel in first gear is over 900 lb.
Since the thrust curve is directly related to the torque curve, any changes to the torque curve would be magnified at the rear wheel. Even if the overall torque remained the same, if the shape of the curve changed presumably that would be felt at the rear wheel.
It's a pity I didn't do before and after dyno runs when I fitted my 1kg heavier flywheel as I'd be really interested to see what, if any, differences there were to power output or delivery.