Straight tubing, or butted?
Assuming that the center of the butted tubes have a thinner thickness than the straight tubes, such that the joint ends are of similar wall thickness. What are the benefits of butted tubes, beyond weight?
Butted frames are stronger and many people prefer the appearance of a butted frame. Now days most lugs are so simple that it doesn’t really improve the frame’s asthetics. Plus, I’m sure they have the welding techniques down to where lugged frames aren’t any stronger.
I may be confused, but it sounds like you may be describing lugged frames in general?
Cheers
Yeah, I’m speaking in general terms. I know next to nothing about Ti and the process they use.
I believe you are confusing tube butting with lugs. They are independent of each other. Butted tubes refer to the thickness of the tube wall at different points in the tube. Typically this means thicker tube walls towards the ends of the tubes, and thinner in the middle. A straight gauge tube has no butting, since the thickness/gauge does not change throughout the tube. Straight gauge is the least expensive type of tubing since it requires the least amount of work. It does carry a slight weight penalty, but only slight. You can get ti, steel, and al in straight gauge, double butted, and even sometimes triple butted.
Lugs are a completely separate issue. Lugs are one method for attaching said tubes together, typically steel, although occasionallly used with Ti. If you want to see lug work, go look at http://www.vanillabicycles.com/. To attach the tubes together, the tubes are connected to the lugs using a process called brazing with a silver or brass filler. This is like using solder to attach metal parts together. This process does not (necessarily) permanently bond the tubes together. For example, of your beloved steel frame gets a ding in the top tube, or down tube, and you want to get it fixed without ditching the frame, you could get a skilled frame maker to “unsolder” the tube from the lugs, and then replace the tube with a new one.
The other typical method for attaching tubes welding (TIG or MIG). This directly fuses the tubes together making them essentially on piece of metal. No lugs are used. Take a look at a litespeed ti, serotta ti, or merlin ti to see good welding.
Wilson
I’m no expert. I did get a custom frame from Roark this August. It has straight gauge tubing. Love the bike. This of course is because it was made for my dimensions. So it fits really well. I think that the straight stuff will be a little stronger. Probably more impervious to dinging a tube, which could happen easier with the thinner walls of butted tubes. Overall I think Ti is more impervious be it straight or butted. Don’t take my word for it though. Just my first thoughts.
Thanks for your replies, it appears that the only difference maybe price and weight…anyone else.