rob.char said:
I don't see how weight would be much different. Unless the tubes were thicker or thinner. The Flight just looks like it's made of Sanko steel which is the same material as 4130 cromo. Except it's drawn rather then welded into a tube like db tubing. Am I correct? I think the Sanko is made in Japan if it matters to anyone. But 4130 is 4130 right?
Butting a tube does make it thinner in areas that don't need to be as strong as the ends where the joints are. It makes a signifigant decrease in weight and improves ride quality over similar tubes minus the butting. The Sanko tubing is double butted. Most of the steel bikes that are on the list are some version of 4130 Chromoly. For example, the GT Peace is made from Reynolds 520 which is essentially 4130 under a different name.
An Eccentric Bottom Bracket (EBB) tensions the chain by using an oversized bottom bracket shell with an off center hole for mounting the bottom bracket (crank spindle). You rotate the bottom bracket in the shell to take up slack in the chain. This allows you to use horizontal dropouts and quick release skeweres on a Single Speed bike. The reason that I am not a fan of the EBB is that many people have had issues with squaking, slipping, and stripping the fixing bolts. Then again, many people have experienced none of these issues. I just don't want to deal with it.
Another thing to consider with an EBB is that when you change gear ratios, you end up changing the relationship between the crankset and the saddle. Again, it's not a big change, but it is something to consider.
Sliding dropouts give you the ability to use a horizontal dropout and quick release skewer like an EBB. In this system, the dropouts are mounted onto slots at the seat tube/chain stay junction. The disk brake mount is also on the sliding plates so the brake moves with the axle. This is a very elegent design with the only real drawback being that the wheelbase of the bike changes very slightly with gearing changes.
Track ends are the simplest method. If you remember how the rear wheel is mounted in just about any BMX bike, that is a track end. This almost necesitates the use of a bolt on rear axle to prevent slipping. I have heard of some people using Shimano XT skewers with success but I'm not about to try it. Also, since the disk brake is mounted on the seatstays (or chainstays on the On One Inbred and a few other bikes) they must be moved in concert with the wheel with each gearing change.
Frames with track ends:
Vassago Jabberwocky
GT Peace 9r
On One Inbred
Surly Karate Monkey
Redline regular Monocog
Frames with EBB
Gary Fisher Rig
Raleigh XXIX
Niner.....
Bikes with sliding dropouts
Kona Unit
Redline Monocog Flight
This is by no means an all inclusive list. Or for that matter it may not even be a completely accurate list.
