Probably a daft thought,but has anyone given thought to having a freewheeling bottom bracket/cranks?
Would remove mass from the rear wheel and place it nearer the centre of the bike.Bigger axle,interface with the bb on which to mount some kind of freewheel,more rigid,stronger mounting for rear cassette,stronger rear wheel?

Thoughts?

😯

you can get them on trials bikes already.

http://biketrials.com/review/2004_Echo_Stock_Front_Freewheel_Cranks_L401.html

Not that wiki links can always be trusted

for singlespeed or trials (basically singlspeed anyway) i can vaguely see the point. for geared bikes I can only begin to imagine how quickly your rear mech would die

Why do you suspect the rear mech would die fast?

because when free wheeling the chain would still be going round thus the jockey wheels would be going round all the time. also if anything got caught in the chain then the entire mass of the wheel and your momentum would be transferred directly through the mech until you came to a complete stop,

Do you freewheel that much? Point about the rubbish getting tied up is a good one though.

it's be interesting to see how much time you spent freewheeling on an 'average' ride. I suspect it's a fair bit. does a cadence meter/garmin combo give you this info?

you can get fixed rear hubs for cassettes too (here) they are used in trials with the front freewheel so you dont have the problem of gears messing up when back pedaling, also means gears change without having to pedal (as long as your rolling, or do the trials hop/kick/endo and as long as the rear wheel does a rotation you change gear :0)