Doesn't that sound better than "FIXIE" Single fixed gear! Of course I guess Sturmey has a?multiple fixed gear, But SFG has ring to it. NOW the BIG problem, and this I think applies to any riding of the bike,GEAR down, TWIDDLE or SPIN as its now called, DONT push the BIG gears, I had many mates, Track riders mostly, that did have knee and hip problems, also HEART attacks like Beryl. MY best mate John Bradbury a top local track rider was lost due to this,a few years ago.Of course other problems can cause this to.BUT you can help yourself by gearing down, Like other members of my age I am still riding with No problems.Work on style and pedal motion, DON'T worry about the speed, it will come with the?miles of riding. Lance the man, how does he do it. never below 100rpm or so, EVEN up a bloody mountain, The great Coppi pushed the BIG gears, how long did he last?? a chap on the trail that I ride in Parker,?always pushing a 56X11 looks like slow?motion when he goes by, Cant ride anymore his KNESS went out! jogs a lot now.45yrs old! is it worth it?? Cheers John Crump OldandtwiddlingBrit, Parker. Co USA?