I wanted to go penny-farthing for ultimate efficiency but the wheel can't get big enough.
I think the weight difference in fixie vs multi-speed is inconsequential; emptying out your colon before departing would have a larger effect.
I wonder about the drivetrain efficiency difference. I've seen derailleur systems credited with 92.5-98.5% efficiency, depending on gearset and tension. Fixed ratio couldn't be 100% and assuming there's no reason it wouldn't be worse than the best derailleur scenario means we'd be comparing 98.5% to 99% or 99.5%? Either way I wouldn't think that's detectable to the rider.
I bought my 27" framed Fuji in 1983 and for quite a long while put 25+ miles on it daily. Sure wish it had an odometer- am curious how many miles are on it!
