# What is a lugged frame?



## KendleFox (Sep 5, 2005)

Hi Everyone

Just looking at older Ebay bikes, and I dont know what a lugged frame is, or if it is good or bad? I'm thinking it is a method of construction, but cant seem to find info on it. If some of you know of bad construction methods, please do tell, so I can avoid a bad purchase/

Thank you so much...


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## sgt_hedgehog (Jun 28, 2004)

*lugged frames are...*



KendleFox said:


> Hi Everyone
> 
> Just looking at older Ebay bikes, and I dont know what a lugged frame is, or if it is good or bad? I'm thinking it is a method of construction, but cant seem to find info on it. If some of you know of bad construction methods, please do tell, so I can avoid a bad purchase/
> 
> Thank you so much...


a lugged frame is a frame (all most always steel) where the frame tubing are bonded together at the junctions by other pieces of metal, which are cut into sometimes very intricate shapes. They're always the most unique looking bikes, because there are so many shapes of lugs.


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## northcoast (Jul 11, 2003)

The first photo is an example of a lugged frame that is pinned and ready to be silver brazed (not TIG welded)

The second photo is an example of a TIG welded frame. No lugs, see. Just the tubes.


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## cpuffe (Aug 1, 2004)

A lugged frame is steel tubes held together by investment cast lugs and fillet brazing or silver soldering to make a bike frame. Generally this is very good (especially for people who began cycling in the 80s or earlier, or who can appreciate a work of art).


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## Jesse D Smith (Jun 11, 2005)

northcoast said:


> The first photo is an example of a lugged frame that is pinned and ready to be silver brazed (not TIG welded)
> 
> The second photo is an example of a TIG welded frame. No lugs, see. Just the tubes.


Good post, good photos, good explanation. I like it when I read a question, and know that pictures will explain the answer better than words, and someone else comes up with goods.


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## RodeRash (May 18, 2005)

I'm not up to speed on current frame construction. 

Older steel frames, (60's 70's and before) used butted tubes. The tube wall was thicker at the end than in the center of tube length. The tube needed to be "butted" to a specific length for a specific frame and so the standard "double butted" frame constructiong was the strongest and most expensive way to build a frame. 

Reynolds 531 doubled butted tubes (British) and Columbus doubled butted tubes (Italian) where held in the highest esteem, and frames promeninently displayed Reynolds and Columbus tube construction decals. 

The most expensive frames were "all 531" or "all Columbus" -- all the tubes in the frame/fork were double butted. 

Less expensive frames would use Reynolds or Columbus in the three main tubes. 

Lugs were discrete items unto themselves and had their own brand names. Nervex lugs (French) where ornate and highly regarded. Prugnat lugs (I think Italian) were more spare, and also highly prized in a frame. 

Lugged frames were "brazed" or "silver soldered" -- in either case the lug and tub were pinned together in a jig, and the joint was "sweated" with a torch while the braze or silver solder flowed into the joint between the lug and the tube. 

Silver solder uses a lower temp. than brazing, and seemingly causes less heat distortion and "tempering" of the steel in the frame/lug. Silver soldered frames where most expensive. 

Alloys in "brazing/soldering" vary a great deal. But it's important to note that the frame tubes are not melted, nor is the metal in the lug. The "solder" or "braze" flows at a temp. lower than the melting point of the steel frame. 

Welded frames in today's modern bikes have the tube metal melted and "welded" or molecularly joined with the metal in the welding rod. 

Once the lugged frame is soldered/brazed, a specialized frame builder will clean up the joints on the frame. This is art work in itself, and highly detailed. Once the lugs are cleaned, they were often chrome plated, and then the frame was painted with the lugs "masked" so that they contrasted chrome against the paint. Pin-striping around the edges of the lugs often further contrasted the lug work. 

A well made lugged steel frame is a work of art. There are probably lots of photos of lug work in the "retro" section of these forums. 

Here's a nice site which discusses steel lugged frame construction. 

http://www.cwo.com/~lunarlab/

And here's a photo of a Nervex lug on the seat bracket of a bike.


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## KendleFox (Sep 5, 2005)

WOW!!!

You guys are the "google" of the bike world!!!

Thank you so much for taking the time to teach me about the lost art of lugged frames. It is always nice to know that people like you are so willing to help us newbees out, so we can enjoy the biking lifestyle.

Thanks again...


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## Frank121 (May 14, 2002)

*Chromed head tube lugs*



KendleFox said:


> Hi Everyone
> 
> Just looking at older Ebay bikes, and I dont know what a lugged frame is, or if it is good or bad? I'm thinking it is a method of construction, but cant seem to find info on it. If some of you know of bad construction methods, please do tell, so I can avoid a bad purchase/
> 
> Thank you so much...


Chromed head tube lugs from a Colnago Master, Conic SLX, and Superissmo


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## rogger (Aug 19, 2005)

.....


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## northcoast (Jul 11, 2003)

RodeRash said:


> Alloys in "brazing/soldering" vary a great deal. But it's important to note that the frame tubes are not melted, nor is the metal in the lug. The "solder" or "braze" flows at a temp. lower than the melting point of the steel frame.


Very important point.


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## Kerry Irons (Feb 25, 2002)

*Well, not really*



cpuffe said:


> A lugged frame is steel tubes held together by investment cast lugs and fillet brazing or silver soldering to make a bike frame.


Lugs do not need to be investment cast. Investment cast lugs are the highest quality lugs, but many fine bikes were built with lugs that were not investment cast. 

Fillet brazing, as it's name implies, is a joining technique where the brazer puts down a fillet of brazing compount at the joint (looks similar to the weld line in the TIG welding example) and DOES NOT involve lugs. Fillet brazing is an alternative to using lugs.


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## omniviper (Sep 18, 2004)

Frank121 said:


> Chromed head tube lugs from a Colnago Master, Conic SLX, and Superissmo



those are awesome pics my friend. im assuming those are from your stable. you are very lucky


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## RodeRash (May 18, 2005)

Colnago has always featured unique lug work in the past. Cinelli and many of the custom English frame makers were notable for the lug designs. 

Frames used to be constructed all pretty much of the same materials. It was the lugs and the style that set one bike apart from the next.


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## mandovoodoo (Aug 27, 2005)

RodeRash said:


> . . .
> Less expensive frames would use Reynolds or Columbus in the three main tubes.
> . . .
> 
> Once the lugged frame is soldered/brazed, a specialized frame builder will clean up the joints on the frame. This is art work in itself, and highly detailed. .



The 3 main butted sets generally had straight gauge forks & stays. Made for a less supple ride and more weight.

Some makers would do a lot of work after brazing. I always detailed the lugs carefully prior to brazing, made sure the tube miter was good, made sure I had about .002" radial clearance or whatever the particular material needed, and then flowed the joint in a manner where cleanup was minimal. One can braze so the feed point and the last glob of brazing material either aren't visible (inside the bottom bracket) or get cut off (e.g., seat & head tube joints). This was the trick for production work - clean setup, clean brazing. With silver, hot water and a brush will often get off the flux. Then a little emory cloth and one is done. Really was fun.


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## naawillis (Oct 6, 2004)

Frank121 said:


> Chromed head tube lugs from a Colnago Master, Conic SLX, and Superissmo



can you say bling bling?


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