Originally Posted by LóFarkas
If you replace a tensioner-less ss freewheel with a fixed cog, other things equal, you get absolutely no efficience improvement. Zero. Uphill, downhill, northern or southern hemisphere, wearing a clownsuit, whatever. The route of the chain is where it's at, and that's the same with fix and ss.
Found this thread through search... worth reviving.
The pdf linked above gives a very strong argument for why fixed is more efficient than SS... The cranks turn themselves at the top of the stroke where the rider can't put in as much power.
With that said, I'm thinking of removing the derailleurs and inner chain ring on an old 10 speed that shifts just fine.
I'm not that strong a rider, but my favorite gear is 48/18 (72"). I like climbing up 7% grades in 40/18 (60"), and the lowest gear on the bike is 40/22 (49"). I'm not really used to standing much, but the bike feels suited to it, and going up seated at 40-50 rpm is ok. How do you decide what gear ratio to use?
The straightest chain line would be 48/16. And I have other bikes, including a slightly slower one with STI shifting and wider gears, and rides where there are no climbs above 5% (72" would be ok), and rides where 10%+ climbs are very short.
From what I gather, getting rid of the deraillers will increase efficiency both because of weight savings (close to 24oz I guess) and because the chain doesn't go through extra pullies.
Can I easily switch between 2 close cogs on the back by just not seating the wheel as far back as possible?