Why SingleSpeed?

  A singlespeed's chain runs directly from the chainring  to the rear sprocket and back. A geared bike's chain snakes around two jockey pulleys to a sprocket that  is out of line (left-to-right) from the chainring by  much as an inch. Even without the chainline issue the  improvement is at least a couple percent, and compared  to some of the more crooked chainlines you might run  on a multi-geared bike, the difference can be quite  a bit more than that. Believe it or not, you can feel  the difference. Don't believe me? Find a bike shop that  sells a few singlespeed bikes, and pull both a singlespeed  and a geared bike off the rack. Now crank the pedals  backwards pretty hard and let go. Notice how much longer  the pedals spin on the SS bike? That's the difference  in efficiency, and it's even more pronounced under load.

Maintenance.  No derailleurs to adjust, no jockey pulleys to lubricate,  no cables to clean. Most of the maintenance most of us do, other than tires, is on the drivetrain. With  a singlespeed all you have to do is take care of your  chain. That's IT.

Durability.  No rear derailleur to tweak on trail obstacles, no shifters  to go bad, no front derailleur to jam, no 11-tooth cogs to wear out early and force you to replace your cassette  before its time.

Weight  savings. To be honest, I still have the rear derailleurs  on my bikes so I can run gears when I want, so I'm not seeing that much weight savings. BUT even so, when I  pull off my cassette and replace it with a single cog,  I'm taking away about 220 grams. That's half a pound.  I can easily feel the difference when I pick up the  bike. Go truly singlespeed by stripping off the derailleurs,  shifters and cables, and you can end up saving 2-3 POUNDS.  People spend hundreds of dollars to lose that kind of  weight off their bikes, but with singlespeeding you  can do it for free.

Concentration.  You don't have to think about what gear you're in. You  don't have to plan your downshift ahead of time when  you come to a stop in traffic. It's not like shifting  is THAT much of a mental burden, but you'd be surprised  how many brainwave cycles singlespeeding frees up for  other things. Like paying more attention to traffic.  Like paying more attention to your body english, line  and speed when you attack that rock garden. Singlespeeding makes you a better technical rider.

Momentum.  1. On a geared bike, when you start losing speed on  a climb, you downshift, and you let off the power to  do it ... which slows you down even more. On a singlespeed,  you stand up and hammer. You get more momentum going  up the hill (although it can be exhausing at times!).  2. Because you know climbing can get tough if you bog  down too much, you pay a lot more attention to preserving  your momentum, and you're less likely to sap away precious  momentum with your brakes when you don't need to. 3.  Because you carry more momentum going uphill into difficult  technical sections, you have an easier time getting  through them in the uphill direction. Why is technical  terrain harder going uphill than downhill? Speed.

Pride.  Let's be honest here. It feels pretty good doing that  bad beeotch of a climb in a gear twice as tall as you  would have on a geared bike. And people that aren't  ordinarily impressed by others' riding are sometimes  impressed that you can ride a particular trail AT ALL on a singlespeed.

Those are the reasons that are most important, but singlespeeders are a diverse group (which is a good  thing) and here are some other potential legitimate reasons which to respect:

Elegance.  A singlespeed bike has a really nice clean, elegant look to it, with no derailleurs hanging  off various places, shifters cluttering up the handlebars,  and shift cables running along the tubes.

Cachet.  It's a fringe activity. You're a member of a pretty  exclusive club if you're a singlespeeder. There's always  the danger of it being a trendy fad, which means someday  it won't be cool anymore, but I don't think where anywhere near there yet.

Making  a statement. There are a lot of people who are fed  up with planned obsolescence, Shimano's dominance of componentry, and/or the over-engineering of today's  bikes. Some people like making a statement about one  of those things, or about noncomformity, stickin' it  to the man, or maybe something else they think singlespeeding  stands for.

Boredom.  Some of the people on this forum are extremely accomplished  mountain bikers. They've ridden it all. Singlespeeding  is a new challenge.

"Singlespeeding  can be an experience that demands more of a person
,  and so a person finds that extra drive, that extra strength  to do something that perhaps he didnít believe  he could accomplish before. Or even relate to. Singlespeeding is quiet. Itís simple. Itís pure. But itís  way more than that -- itís personal."

Single Speed Links

SheldonBrown.com -  single speed conversions
Spot.com -  frames and components
SurlyVille.com -  frames and components
PaulsComponents.com -  components
WhiteIndustries.com -  components
PhilWood.com -  components
DrunkCyclist.com -  all sorts of BS (bike stuff)
SingleSpeed Outlaw