I’m building a cross bike for Lonnie V. of Spokane WA right now. The frame is steel with swoopy seatstays and S&S couplers. I build quite a few coupler bikes every year in steel and titanium and I love them. The couplers are a beautifully made part that work incredibly well. They add cost and a little weight but they have absolutely zero affect on the ride of the frame. The idea that got Steve S (the maker) to design and start offering couples was that it allows you to pack your complete bike in a case that’s 26×26x10″.  That is the max size airlines allow for checked bags without a fee. Since the airlines charge $75 and up for bike boxes it doesn’t take long if you travel a lot to pay for the couplers and case. Another major advantage to the couplers that is largely overlooked is the convenience of getting the bike around. The hard case has wheels and a handle so it can be easily rolled around the airport, but also, unlike the large hard bike cases, S&S cases fit easily in the trunk of a cab. Pricing is a bit spendy at $600 for steel and $900 for titanium plus the hard case $430 and various other accessories that add up to about another $100 but like I said, if you travel a lot they pay for themselves.

I will be in the shop today. If you are in the queue and received an email from me Friday to discuss design, feel free to call. Lonnie, I’ll be posting pictures of your frame tomorrow, it’s just about done.

So here it is, #2. Remember I’m a Framebuilder so I’m way out of my element when it comes to talking to a camera. I’m actually a lot worse than I look but Aaron (the producer) did a good job of keeping me from looking like a complete buffoon.We had to break it into three parts in order to upload it to YouTube so we could take advantage of their streaming.

I’m building a titanium frame for Ned right now and it made me think, some might be interested in learning about the infamous “double pass” weld. You hear the term kicked around a lot but what is it, really. Here is the scoop, the double pass (DP) weld is used primarily for titanium although I have seen it employed on some Italian aluminum bikes.  You never see it on steel. You’ll hear all sorts of reasons why people use the DP weld on titanium, most notably because it’s needed in order to produce the penetration necessary to create a strong joint. The biggest reason most builders use the DB is because it produces better looking welds, welds that are out there for the world to see. You don’t get to cover them with paint like you do with steel. The reason you see it done with titanium but not steel is because steel suffers from a reduction in strength through the heating cooling cycles that titanium does not. A person could DP steel but the likelihood of future failure would be very high.

So here is how the double pass works. First you must have very tight fitting joints. The builder will then weld the joints without the filler material that is used in a standard single pass weld. This is called a homogeneous weld or, for simpler minds like mine, the first pass (FP). The result is a very small shiny joint that is not strong enough to be used. Some builders will go around all the tubes like this without any filler but there are all sorts of variations on the theme. For instance I  like to use very small filler wire in all the crotches that require more filler during the second pass in order to avoid undercutting. I also like to grind the transitions in the FP  that exist between the homogeneous sections and the sections that I’ve used a little filler. The gives me a consistent FP to follow and allows me to create second pass also known as the “dress pass” that looks better. Once the first pass is done the builder will then weld around the frame with the second pass using filler just as they would if it was a single pass weld. Since the first pass is done, the frames alignment is fixed and the normal challenges of filler angle, introduction rate, etc don’t exist, the builder can just concentrate on producing a consistent, pretty weld. Once they’re done with the second pass the weld is complete.

There is no single “right” way to to weld. Most builders have their own style and you can see it in the final results. Some use a single pass, others use a double. Some pulse, some don’t. If you pulse, the appearance of the final weld can vary dramatically depending on the pulser settings. Other variables are filler rod diameter and the rate of speed at which the welding is done. Some welds are super pretty and consistent and others…not so much.  The important thing to remember is just because a weld isn’t pretty doesn’t  mean it’s not strong. And conversely just because is pretty doesn’t mean it’s strong, although I will say, if a welder can make a weld pretty, they can probably make it strong. It’s not harder to make a weld pretty than not if you know what your doing.

So there you have it, the “Double Pass” weld. Below are a couple  pictures of Ned’s bike with both a first and second pass. Ned, your frame is just about done and we’ll be assembling it soon.

Loretta and I have a few things going on this week. The big news is that Loretta is finishing up her Photo Studio. Loretta has spent the last  10 years accumulating stuff to eventually use in her own studio. We were finally able to commit space and now  have 700sf of windowless space that adjoins Strong Frames. She will use it both for her own personal artistic projects as well as getting images for the Strong Frames website. We still don’t have all the fancy lighting, softboxes and stuff like that but we’re looking around for good deals and used stuff, hopefully we’ll have lighting setup soon. Currently she makes do bouncing light off of foam core and other little tricks that produce good results but take up a lot of time and space. Personally she is interested in more artistic photography like B&W for which she’s building a dark room and emulsion transfers. By the time she’s done with a lot of her stuff you’d never know it started as a photo. I’ll try to post examples someday.

I’m building Ned’s butted titanium road frame. It’s a full build getting Sram Force with some very nice carbon bars, stem, post and DT wheels.

Lastly, webisode #2 is done. We should have it posted today. I’ll post a link on the Facebook page as soon as it up and of course dedicate a blog post to it as well.