steelframes-lugged vs. butted?
 

How much better is a lugged frame than a butted frame. I have an older italian columbus lugged steel bike, but I notice all the new steel bikes are butted.

What are the advantages/disadvantages of each?

It's not butted.It's TIG welded. Neither is better assuming quality construction, just different. TIG is cheaper,that's why it's used so much.

Most lugged frames are butted. Butting has to do with the thickness of the tubing on the end. The lugs have to do with the joining process. Common methods to join bicycle tubes are lugs (brazed), welded and fillet brazing.

Most mid-to-high-end lugged frames are butted. None of the lugged frames of basic entry-level 10-speeds of the 1970s (Peugeot UO-8, Motobecane Mirage, Raleigh Record, Steyr Clubman, Nishiki Custom Sport, etc.) were butted.

Thank you,

I appreciate you clarifying the differences between tig welding and lugs as methods to join the frame

True. I was simply generalizing.

It's also strong than brazed, welded and fillet brazing

Butted tubing is a tube that its walls are thicker toward one end. Double butted is if the tubes walls are thicker on both end, and triple butted is when the tube wall has 3 levels of thickness along its length..

Typically you would use a thicker wall in areas such as the bottom bracket where most forces are created, and leave the middle of the tube thin walled for saving weight..

Here is a nice description on how Reynolds makes butted tubing..

Really? Why??

TIG is welding, and so is MIG and good 'ol stick welding.. all this are considered Arc Welding. Basically it is using an electrical arc to heat and melt the edges of the 2 pieces of metal to be welded, and adds a third material (the stick, or wire) that it mixing up with the two other metals to make it all one piece.

The issue with welding and bike frames it that the high heat changes the character of the tubes around the weld area, and in some cases it hardens it and makes it more brittle and less flexible.
On the other hand, a welded frame can have any shape and geometry you want. Just cut the tubes and weld, as you are not restricted by the angles of the lugs. Also, welding can be done automatically by machines (as a matter of fact machine can cut tube and weld better then human :) ), and the frames are alot cheaper to make...

Lug construction is traditional and personally I think it looks prettier..

Brazed construction is when they use brass the way you use solder to connect 2 surfaces of steel to each other. Brazing allows you to build lug less frames (geometry freedon) and never heat up the tubes to the point of melting.. Also, Brazing joints can be made smooth and pretty and the frames can be made to look stunning with no use of Bondo (filler)...

see: http://rivendellbicycles.com/html/101_lugs.html
http://www.anvilbikes.com/story.php?news_ID=19&catID=3

My frame is fillet brazed with a lugged BB. I'll post a pic of one of the fillet brazes when I can. They look really good although they are marginally heavier than welds :).

This is actually a complicated and fascinating subject. There are some fancy modern steels on the market (such as Reynolds 853) which are designed to improve their strength characteristics when welded or brazed. Check out http://www.reynoldsusa.com/. These modern high alloy steels are approaching the strength to weight ratio of titanium!

All quality frames are butted ( tubes thicker at ends for more strength) that I've ever heard of , and the turnip truck is miles down the road
If you mean welded when you say butted vs brazed -tough question many arguements for both, I'm NOT going into them since it may be a moot point since either process, when done right, produces a machine that will last a long time. (To my eye a Lugged frame is more beautiful)

I'd say most now favor welded frames since the welding techniques and the steels (such as self hardening at temperature Reynolds 853) have been much improved the last few years

Although I find the older lugged frames prettier, there were a number of reasons that lugs dissapeared.
Lugless, TIG welded frames first became popular on mountain bikes. The TIG weld is as strong or stronger than a lugged unit although both types of construction are plenty strong.

One big reason that lugs dissapeared is that a set of lugs will only accomodate a few frame sizes due to the different frame angles needed to make extra small or extra large frameserts. Hence, the expense to tool numerous sets of lugs would result in a frame that would be more costly.

Also, lugless construction means that the frames can be robotically welded which is much cheaper and less complicated than brazing tubes inside of lugs.

Lastly, without lugs you have a lot more freedom insofar as the diameter and shape of the tube. With lugs, you're forced to use steel and small diameter steel tubes. Without lugs, you can vary the shape and diameter greatly using various materials (aluminum, titanium & steel).

The next frontier is the new generation of carbon frames. For a great example of sexy tube shapes using carbon, take a look at the De Rosa Tango:


http://www.velonews.com/tech/report/...es/6888.0.html

The very reason we do not like TIG welding for race cars frames makes it an ideal method of assembling bicycle frames. The heat is concentrated right at the held of the welder and it does not melt as much of the base metal. It the light gage tubing used in quality bicycles, this is a major advantage. As has been stated previously, with aluminum or titanium frames, TIG is the only realistic assembly method today.

Any of the three assembly methods can produce a quality bicycle. Individual preferences should decide.

Doc

Wow what a load of crap some have so happly donated here!!! First lets start with Tom, Tom had a lot of good ideas except for some statements like: "The TIG weld is as strong or stronger than a lugged unit although both types of construction are plenty strong." That's pure hooey, the lug construction is every bit as strong and stronger then a tig weld; the reason MTB went that route was to save money on construction cost-THATS IT!-which Tom alludes to later in his post!

The second statement Tom makes: "One big reason that lugs dissapeared is that a set of lugs will only accomodate a few frame sizes due to the different frame angles needed to make extra small or extra large frameserts. Hence, the expense to tool numerous sets of lugs would result in a frame that would be more costly." Where did that come from? Bike manufactures for years were making bikes from the smallest to the largest frame size's and used lugs; the molds for all these various angles with lugs were already made so making the frame to fit whatever size rider was never an issue.

Tom's third statement: "Lastly, without lugs you have a lot more freedom insofar as the diameter and shape of the tube. With lugs, you're forced to use steel and small diameter steel tubes. Without lugs, you can vary the shape and diameter greatly using various materials (aluminum, titanium & steel)." This was a half true statement-the wrong part was the diameter and shape of the tube...kind of true, but there were oversize tubesets called OS and MAX tubes that had lugs available for them, and some such as Colnago used a tube with a fluted shape to it and they had lugs to fit it. Making a lug of various shapes, sizes and designs is not a problem with wax castings, but to keep complication down they limited it to 2 different tube diameters and limited it to tube shape-mostly round except for the Colnago.

Then Astra said that lug construction is heavier, problem is with a welded frame they have to have the ends thicker to buttress the tube when it's welded so the thicker ends almost negate the lugs weight and still is not as strong as the lug.

Read the sites I posted earlier, plus here's more for your entertainment pleasure: http://www.henryjames.com/faq.html
http://www.epinions.com/content_1176608900
http://www.worldclasscycles.com/JACKSON-HOME.htm (read fabrication methods).

Well, yours is not exactly stink free.... The 'fluted' Colnago tubes are round on the ends where thay plug into the lugs,except at the base of the seattube where the rounded section is slightly ovalized. Identically butted tubesets are used in both lugged and tig welded construction, meaning that a welded one isn't necessarily thicker or heavier. I could go on,but..............

Well you could go, but you haven't read the web sites to blow your thesis to the wind. But hey your right, no one listens until you make a mistake.

Well, there is right and wrong in any of this stuff, and Neither James or Jackson are 100%. A Columbus Data book list 'lugged' and 'tig' tubesets for the very lightweight nemo and genius tubesets.Weight advantage for the lugged is 22 and 31 grams respectively, and part of that goes away when ends are cut to length. Other listed tubesets are the same for lugged and tig,being thick enough in HT and other critical places that they can be lugged or tig. And this does not even get into the air hardeing alloys specifically engineered for tig welding.The Henry James statament that tig seattubes require external butts at the seat cluster is BS, as I have several that aren't.

So DocF do you use mig or stick. I know that stick is generally required for code in construction but the pieces are really big and can soak up the heat. Seems like mig would be much faster, no chipping and brushing every minute and a half and you wouldn't spend as much time letting parts cool.

Mig is the best way to put a race car together, and a really good welder (which I am not) could do a wonderful job on a bicycle frame with mig. When I was actually doing fabricating, I trusted my work on .083 and heavier stuff. The .040 and smaller bits were usually done by a guy who was aircraft certified. This is all open wheel stuff built with 4130 aircraft tubing. Some of the old time fabricators gas welded everything.

Most of the sprint car and midget frames produced today by Beast, J&J and others are TIG welded because they are throw away designs that can't be straightened and the speed and economy of TIG reduces the cost to a level that some teams find tolerable. For the guy racing at a local track, it does present problems.

Stock cars are made with DOM tubing (about the same as "hi-ten") and I used a stick welder for them.

Would I attempt rewlding a bicycle frame? Certainly, not one that was of any level of quality. My skills are not good enough to do the very light gage tubes.

Doc

anyone know anything about peugeot's "patented lugless brazing technique" from the 80's. Most of these bikes don't look welded at all. The welds are tiny...?

(I pray I've got this right, this is a pretty tough crowd)) I was sold a Peugeot 501 Reynolds from that era for $25 by a local bike painter , only identification was a decal that said "Nice" on one side and "12 vitesse" on the other. He has a lot of experience with painting and frame repair, but he couldn't figure how it was done, either. He determined after it was sandblasted that the joints were silver brazed, he was pretty impressed, thought it was crazy to do on a production bike. All the cable guides and the shifter bosses were affixed that way, too.

That de Rosa is de Ugly. Looks like it got hit by a shockwave.