Has anyone considered making a UW out of a Coker rim? Does that sound possible? Would it would be too heavy? For UW riders, would you place the pedals 6" from center (like 6" crank arms), or more?
You wouldn’t want to make the ‘cranks’ too long or it might smart a bit. 
I don’t thing weight will be an issue. I find heavier wheels ride better than light ones.
There are a few old pics of people riding penny farthing (sic) wheels as ultimates. I expect John Foss will have some pics.
Nick
