It's not the same though. Don't ask me why, but 5lb off the bike is far more noticeable than even a stone off the rider.
If we ignore all the other variables between bikes, I can only see 2 reasons for this:
- You can't just 'drop' 5lb of flab by clicking your fingers, but you can switch bikes in seconds - you therefore associate light bikes with a tremendous increase in speed, but never notice the effects of changed bodyweight. OR
- It's the unsprung weight thing, well known to car engineers**. You don't go faster by moving 5lb from the bike to your body*, but the increase in ride quality and 'lively' handling makes for a more pleasurable experience, giving a psychological boost.
M
The footnotes:*I'm being heretical here, suggesting we carry as much stuff on our body instead of the bike. Well, I think for pure performance, this probably works. But a heavy rucksack will still tire you out over a long ride, enough to banjax any minor handling improvements!
**Who laugh at boy-racers adding bigger tyres+wheels, as they are usually heavier, and thus often result in WORSE handling. As a Miata driver Roger, you of all people should know about this