Well I dropped my chain yesterday and it bent a link. No one could spare a power link, so I chopped the chain and put it back on... I couldnt shift above 4th gear, Because I was worried about my RD stretching way out.
in 3rd-2nd gear the chain got so tight it wouldn't shift at all I had to move it manually.
So I rode the whole trail in my 5th gear in the back and my 2nd ring up front
(dont know the exact tooth numbers, but its an 8 speed bike) and holy crap... it was a challenge going up them hills. But I never once stopped or walked! I still ran a 31.4 minute lap, which is considered fast, my normal times range between 27-30 mins.
But I'm conviced that single speeders must be
A: Mentally Insane
B: Freaking Ripped as heck