For those of you who don’t know what a butted tube is, it’s a tube that is thicker at each end then in the middle section. You can look at it as thinner in the middle or thicker at each end but the idea is that it allows for a lighter tube while still offering the builder enough material at each end for joining. The pro’s to butted tubing are lighter weight. The con’s to butted tubing are less dent resistance. I offer titanium in straight gauge and butted. I recommend straight gauge to nearly everyone but there are some customers that will want the added lightness of the butted titanium and are prepared to sacrifice a little durability. Butted titanium frames are on average about 0.3 pounds lighter than straight gauge and they cost $400 more. As a frame gets larger the weight savings increases. There is little to no perceptible ride difference between butted and straight gauge tubes. Below is a very nice butted titanium frame we just finished up for Ned. As I recall the frame weight was about 2.6 pounds for a pretty large frame of medium stiffness.

I’m a complete geek, so when it comes to bikes on the Internet I spend a lot of time looking at other builders sites and following the message boards. It’s fun to see what other builders are doing, how they do it and what motivates them. I have a handful of blogs I follow everyday and a handful of message boards I visit several times a day. I’m not much for posting on the message boards, I’d rather just see what others have to say. I also don’t want to come across as though I’m marketing so I think it’s safest to just lurk.

My favorite board is Velocipede Salon, it’s easily the most sophisticated collection of users when it comes to custom bikes. Lot’s of other builders participate as well. The Serotta board is also a great board. It’s transcended Serotta and evolved into a community that is loyal to cycling in general and not just the Serotta brand. MTR had a Framebuilding forum that’s fun watch as well.  There are  few experts that participate but more than anything it’s a place for the hobbyist to look for resources and assistance.

http://www.velocipedesalon.com/forum/index.php

http://forums.roadbikereview.com/

http://forums.mtbr.com/

http://www.serotta.com/forum/

http://www.bikeforums.net/

Also, just so we have a few pictures on this post, I’m currently working on Nick L’s titanium 26 Freeride MTB with sliders. Here are a couple images of t he progress so far. I’m about done bending and cutting tubes and should start welding today.

I got a few frames back from paint, both with very cool paint jobs. One is for Curtis H. and the other for Kyle B. I also finished up a titanium frame for Ned that will get assembled today and a steel frame for Lonnie which goes to Spectrum for powder coating. While Loretta and Bill get those frames built, photos taken and boxed I’ll be finishing up on a titanium frame for Kurt S. Kurt’s frame should be done today and shipping this week. He’s getting Dura Ace 10 with custom wheels and a Power Tap hub. It’ s going to be very cool. I’ll be posting a very complete pictorial of Kurt’s build on my Facebook page and Flicker as soon as I’m done but I’ve added a few images to this gallery for now.

From time to time I screw something up. Mistakes almost never make it out of the shop and in most cases they’re easy to fix. Most of the time it’s something harmless and stupid and I just redo it and it’s not a big deal. But there are times when I make a mistake that cannot be completely fixed. The frame below is one of those times.

As usual, when building this frame I got to the brake cable stops and had the frame held in the stand by the Toptube upside down. I put the stops on and off I went around the rest of the frame putting the braze-on’s on. Well as it turned out, I had the frame rotated 180 degrees from my normal position and the cable stops were put on the wrong (drive) side of the Toptube.  You wouldn’t think this was a big deal, seems like you can just take them off and move them to the other side, right. Well you can, the problem is that the frame is made of Columbus Spirit which is an Extralite tubeset. What  that means is that when the stops were removed there was some deformation on the tube and because the tube is so thin, I can’t do any reheat, filling or finishing to get rid of the ripples that were left after removing the stops.

So, I went ahead and put the stops on where they belong and had the frame painted. Of course the frame can’t be delivered to the customer so as a result I have a frame in stock with a minor blem. Here is were you come in. The regular price of this frame is $1850. Because of the minor cosmetic flaw I’m blowing it out for $800. If you are lucky enough that it fits you it’s a great deal. The imperfection is under the Toptube in a very inconspicuous location and there is no structural or durability issue. The frame will come with the normal Extralite three year warranty to any buyer that does not exceed 200 pounds. There are pictures of the frame below including close ups of the trouble area. Please feel free to contact me with any questions.

Regular Price $1850

Blem Price $850

You hear a lot of stuff out there about how hard titanium is to work with. While it’s true there is a small margin for error, I think the super thin steels and stainless hybrids are much more challenging than titanium. One of the reasons that titanium has such a reputation for being difficult is contamination. At about 800 degrees titanium will alloy with atmosphere and the contamination will cause the material to become very brittle. Of course all welding occurs well above 800 degrees and if contamination occurs the weld will fail. So to prevent the titanium from being exposed to atmosphere people have done a couple different things.

One every extreme measure, and in my opinion overkill, is to weld the titanium in an inert chamber. Usually a chamber  with a  window and arm holes like a sandblast booth that is pressurized with argon. This method works, but it’s expensive and it’s overkill, it’s also difficult to weld complex items with hard to reach areas like a bike frame. Few if any bike builders use chambers.

The way most framebuilders including myself protect titanium during he welding process is by careful purging of the local weld zone on both the front of the weld and the back of the weld (back purge) directly in the area being welded. The way this is done is by first adding venting between the tubes of the frame, then plugging any holes such  as the HT, ST and BB. We then fill the frame with Argon, an inert gas that does not negatively affect titanium during welding. That process protects the backside of the weld and is called back purging. The front of the weld is protected by argon being introduced to the weld area by a diffuser cup that is part of the welding torch. The gas (argon) the cup sends is the I in TIG and is used for any material when TIG welding but in the case of titanium more gas is used and it covers more area. When welding the welder then moves the cup at a rate of speed which allows the titanium to cool to below 800 degrees before the cup has advanced beyond it.

You might ask, how does the welder know if they’ve been successful preventing contamination. Well, that’s simple, color. Unlike a good clean steel weld in which you want that shiny blue/purple color, titanium must have little to no color at all. When titanium is contaminated it will have a beautiful blue/purple color around the weld and that  indicates you have contamination. A good titanium weld should have no color at all or just what is referred to as a “light straw” color.

I know this may be oversimplified for many but to really do it justice I’d have to write a book and this is more to provide insight than the knowledge needed to go out and weld titanium.

In the pictures of Rob’s bike below you will see the plumbing (green hose) that is pumping argon into the frame. Also notice that the welded areas have no color, that is the indication that the welds are healthy and strong.