Results 1 to 6 of 6
  1. #1
    Find Life to Live Life
    Reputation:
    Join Date
    Jul 2004
    Posts
    135

    Types of steel: lugged, double butted, etc??

    What are the differences between all these types? My bike has Columbus Thron double butted chromoly steel tubing. What does that mean?

  2. #2
    Old and Fixed, Moderator
    Reputation: Dave Hickey's Avatar
    Join Date
    Jan 2002
    Posts
    20,856
    Quote Originally Posted by UCLA_MCDbio
    What are the differences between all these types? My bike has Columbus Thron double butted chromoly steel tubing. What does that mean?

    http://www.m-gineering.nl/buizeng.htm
    Dave Hickey/ Fort Worth

    My 3Rensho Blog: http://vintage3rensholove.blogspot.com/

  3. #3
    RoadBikeReview Member
    Reputation:
    Join Date
    Jul 2004
    Posts
    22

    Good

    That means it's made of pretty good steel tubes. Double butted means the tubes are thicker at the ends where they are joined so they can be light an strong.

  4. #4
    RoadBikeReview Member
    Reputation:
    Join Date
    Aug 2003
    Posts
    777
    Quote Originally Posted by UCLA_MCDbio
    What are the differences between all these types? My bike has Columbus Thron double butted chromoly steel tubing. What does that mean?
    Thron was Columbus's lowest-cost tubeset that had all of the "good" qualities for bicycle tubing:

    Chromoly: Steel alloy using small amounts of chromium and molybdenum. Chromoly steel probably has the best strength / weight / cost relationship of any material for bicycle frames. Not the "best", mind you, just the most even distribution of compromises. All steel alloys are about equally stiff and weigh about the same, by volume. They vary in strength quite a bit. Stonger metal can be used to build a lighter bike, by using less of it.

    Seamless: Formed by drawing "cold" steel over a mandrel. This imparts a grain to the metal, and creates a stronger tube than seamed tubing, which is rolled from sheet steel, welded along the edge, and then processed to remove the seam.

    Double-butted: Thicker on the ends than in the middle. Typical wall thicknesses for bicycle tubing vary from 1.0 - 0.6 in the butted sections, and 0.8 - 0.4 in the center sections. Thron would be at the upper end, probably .9/.7/.9 and maybe 1.0/.8/1.0 in larger frames.

    Lugged refers to one of the three common ways to attach steel tube together to make a bicycle. In a lugged frame, the tubes are fitted into steel "sockets", called lugs. The joint is brazed togehter: heated with a torch and silver or brass solder is wicked into the gap between the tube and the lug. "Fillet brazed" frames are brass brazed without lugs. The builder builds up a "fillet" (fill-it), a little curve of molten brass between the tubes. TIG-welded frames are made by butting the tube directly up on another and passing an electric current through them. This melts the two tubes together. Any method can build a good or a terrible frame, though the different methods have different advantages (and disadvantages).

    --Shannon

  5. #5
    RoadBikeReview Member
    Reputation: Nessism's Avatar
    Join Date
    Feb 2004
    Posts
    1,366

    Thorn info

    Quote Originally Posted by tube_ee
    Thron was Columbus's lowest-cost tubeset that had all of the "good" qualities for bicycle tubing:

    Double-butted: Thicker on the ends than in the middle. Typical wall thicknesses for bicycle tubing vary from 1.0 - 0.6 in the butted sections, and 0.8 - 0.4 in the center sections. Thron would be at the upper end, probably .9/.7/.9 and maybe 1.0/.8/1.0 in larger frames.


    --Shannon
    Shannon, your post is very good overall but I can add some further info regarding the tubing.

    Thorn tubing is "over size" which means it has a 1-1/8" top and seat tube, and a 1-1/4" down tube. The down tube is .8/.5/.8 and the top tube is .8/.6/.8. These wall thicknesses are medium-thick by modern standards but not overly so.

    While Thorn may be on the thicker side compared to some other tube sets, but this is not necessarly a bad thing depending on the purpose of the frame. For example, if stiffness is desired thicker tubes are needed.

    Good luck.

    Ed

  6. #6
    RoadBikeReview Member
    Reputation:
    Join Date
    Jan 2004
    Posts
    591

    Thickness

    Quote Originally Posted by Nessism
    For example, if stiffness is desired thicker tubes are needed.

    Good luck.

    Ed
    Or use a larger diameter and draw it thinner.Thron is just plain cromo., avable is both standard and oversize.

Similar Threads

  1. Replies: 38
    Last Post: 09-09-2004, 07:08 PM
  2. Replies: 14
    Last Post: 08-13-2004, 06:54 PM
  3. Manufacturers of lugged Italian steel frames
    By BNA_roadie in forum General Cycling Discussion
    Replies: 29
    Last Post: 08-05-2004, 02:43 PM
  4. Lugged steel top tube ding
    By rroselli in forum Fixed/Single Speed
    Replies: 7
    Last Post: 07-09-2004, 11:21 PM
  5. Did somebody say lugged Italian steel?
    By EvilGilligan in forum General Cycling Discussion
    Replies: 5
    Last Post: 05-17-2004, 07:10 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

EUROBIKE

Hot Deals

Latest RoadBike Articles


Latest Videos

RoadbikeReview on Facebook