Production Process – Page 4

Gifts

We wouldn’t normally talk about our business here on the 7 where our main goal is to share the awesomeness of riding bikes and to show some of the amazing ways people are riding Sevens out in the world. But it’s Christmas Eve, and we’re feeling all happy and sentimental and above all grateful for where we are in the life of our little bike company. 2015 will mark our 19th year building custom bikes, and that is a gift unto itself. Work is work. It can be hard sometimes, but there’s nothing we’d rather work hard on than building bikes.

If you’re reading these words then you’ve contributed to what we’re doing in some way.

We’ve built more than 30,000 bikes now, all of them one-at-time, by hand. More than money earned, that work is the reward. We do what we do because we love bikes and we love cycling, so the opportunity to work with so many riders on THEIR bike is a gift.

Doing what we do also turns out to be a pretty great way to explore cycling. We ride what we build and evolve our designs out on the road and the trail, bringing back ideas and experiences that inform the next bikes out the door. It’s an amazingly rich way to ride. It helps you feel connected to the bike in ways that are hard to articulate, and that is a gift, too.

When we started out we made a conscious decision to try to bring custom bikes to as many people as possible, which meant doing things differently, developing a manufacturing model that allowed us to turn out more than one bike a day. The core group here, all of whom came from Merlin Metalworks, already had decades of bike-building experience, but what we wanted to do with Seven required us to share that experience with a larger group, and that has brought us so many great young bike builders over the years, all of whom had their own ideas, their own passion. Seven has turned out to be an incredibly rich place to work with a vital collective energy, and that is another gift.

We are also part of an industry with virtually no downside. Bikes improve people’s lives, make them healthier, bring joy, allow them to explore, to connect with friends. It’s nice to work all day and feel what you do has that sort of positive impact on your customers.

The old trope says it’s better to give than to receive, but it can be hard to tell in some instances who is giving and who is receiving. We’re here on Christmas Eve, working so that more people can ride great bikes in the New Year, but we feel like the receiver. We’ve had 18 years of fun, and 2015 looks like another log on that fire. Coming on two decades here in our shop, we’re not nearly out of ideas, and the minute we run low, you, our riders, will come up with the next great thing and gift it to us, so we can build it for you.

Happy Holidays to all, from your friends at Seven.

The Finisher’s Dance

Gritty Nylox bristles whip over the titanium tube and brush off the discoloration left behind from welding. The sound isn’t deafening, but with three other frames being wheeled at the same time, it is pretty loud this afternoon. The final stage, before frames get wrapped up and shipped out, or in my case handed off, is my favorite to watch. Unlike a welder, whose hands move slowly and steadily, frame builders move about like dancers. Twirling around the stand as they flip, twist, and rotate the bike, their performance looks choreographed. Dan C. is working on my bike, but his recital isn’t a dance at all, in fact it’s one of the most arduous parts of fabrication. We call it “FINISHING.”

Before I caught up to him, Dan had already run my frame through the CNC machine where the bottom bracket was threaded, faced, and chamfered. In machining, the bottom bracket starts as a thick walled, round tube. When the down tube, seat tube, and chain stays are all welded on to it, the heat distorts the metal, microscopically, but enough that it’s no longer perfectly round. The thick tube wall is important because our CNC machine will bore through it, expanding the inner diameter to leave a perfectly round hole, which it can then thread. You can see the difference in wall thickness.

Dan had also faced and reamed the 44mm head tube so my Chris King InSet 7 headset will press in evenly. As an aside, the lathe that faces and reams head tubes is my favorite machine in the building. Who knows what it did before it came to Seven, but it looks old and tank like. I bet it weighs several tons. Head tube after head tube, it keeps working, just like new. Spin the crank and it goes round and round like a Record square taper bottom bracket. So cool.

When those two steps were finished, Dan bonded in the seat tube insert, cut the seat top binder notch, and checked the frame’s alignment, making improvements where necessary.

By the time I got back to see how it was coming along, my bike was half way through the wheeling process.

Once the main tubes have been wheeled, and the natural sheen of titanium comes through, he’ll exchange his drill for a ruddy strip of Scotch-Brite. The Scotch-Brite pad gives a uniform finish to the frame that can be replicated at home, at the end of the season, or whenever I want it to look like new.

When the frame passes Dan’s final, grueling, inspection, he’ll attach all of the small parts. The last step is to wipe down the frame with a light furniture polish.

Pretty soon my frame will be ready to build, and I will be bouncing off the walls.

Behind the Mask

Nestled snug in their box, the tubes that will become my frame roll, with the jig, from machining to welding, where they wait to be claimed. Who welds each frame is a matter of chance. Whichever welder is available at the moment takes the next frame in line. In my case, that welder is Stef Adams. Coincidentally, Stef welded my other Seven back in 2005, an Elium SL, and she did such a good job with that one that my thirst for a new bike was stifled for nearly a decade.

While in the machining stage, tubes get coated with grease, dust, shavings, “permanent”marker, finger prints, oil, and who knows what else. To ensure that her welds will last a lifetime, Stef cleans each tube in a two stage acetone bath which wipes away everything, including the boastful claims of the marker. By wearing fresh, cotton gloves she keeps her own finger prints off the tubes in the process.

Sevens are TIG welded (the acronym stands for Tungsten Inert Gas). We pump argon through our frame jigs and into the tube sets as we weld them. The inert argon won’t react with the molten titanium, which is why we use it to “clean” the inside and outside of each area to be welded.

Stef assembles the clean tubes back into the jig, then hooks up a gasket to the head tube in order to create the back purge, plugging all of the external holes in the frame (e.g. where water bottles will be mounted) with stoppers. Internal breather holes, previously drilled into the tubes, will allow the gas to flow from one tube to the next until all of the tubes are overflowing with argon. Argon also flows out of the welder’s torch which protects the outside of the tubes.

A gauge at each welding station lets the welders know when there is enough argon in the frame to begin welding. Stef checks the gauge and begins tacking one tube to the next. A tack is a small spot weld that holds the tubes in place. They make freehand welding more manageable.

Out of the jig and onto the welding table the tacked frame goes. Stef works in a most graceful fashion, twirling the frame around the table, welding a little here, a little there, with the smooth, precise movements that she has perfected over the course of more than seven thousand frames.

Little by little, the frame gets closer to completion. Stef says it takes a few hours to weld a frame as “simple” as mine, but that couplers and other options can add to that. My frame is simple in that it is a straight forward mountain bike, with no additional features or options that need to be welded on. I clarify with her that it is also awesome, and she agrees.

Below are the bridges and zip tie guides. Not too many, means not too complicated.

Perfectly round, overlapping droplets of molten titanium bond the tubes together. A stack of dimes, fish scales, whatever you want to call them, they will hold the frame together for the rest of its life. I think they are beautiful. One of the many artistic achievements of the welder is to make it appear that the weld was done all at once, one droplet after the next, until the entire tube is welded, but in reality, they work in tiny centimeter long increments, which is why the frame is flipped, spun, and maneuvered into different positions as they go.

For a novice, welding can be pretty scary. There is electricity, intense heat, and a light so bright it could blind you. Behind a camera lens, it looks like a brilliant purple and blue light.

But from behind the welder’s mask, it’s actually quite pleasing. The welding mask is tinted so dark that, to Stef, it feels like welding by candle light. She works slowly but steadily. Aiming the torch with her right hand, she increases the heat until it’s so hot that the spindly titanium bead in her left hand melts when she dabs it on the tube. Each droplet adds material and strength to the weld. This style of welding bikes is called the Puddle Bead Method, and was pioneered by another welder at Seven, Tim Delaney. Stef is a master, and does a great job of explaining what she is doing while she works. She makes it look so easy, but I know that if I were at the helm, there would be shouting, catastrophe, and probably a fire.

A job well done and a small token of appreciation.

The next time I check on it, the frame is all together and hanging up in the final machining department, ready for the next steps, so close to completion.

Taking Shape

My friend Matt Sutton is in charge of machining the tubes of my bike. This is great news, not because he is any better at machining than the other machinists, but because Sutts’ audiophilia is currently through the roof, just like mine. He recently stepped up to a new pair of high quality bookshelf speakers to go with his tube amp, and I have some interest in learning about that, so in addition to pestering him about my bike, I also grill him with questions about his audio equipment. I’ll bet he enjoys that as much as I do.

While Sutts waxes poetic about his new KEFs, he picks up an empty box, and starts collecting the small parts needed to build my frame; two 6/4 titanium drop outs and a 68mm bottom bracket are the first to get dropped in. Tube selection comes next. We have an enormous variety of straight gauge titanium tubes, in all different diameters and wall thicknesses. They extend from floor to ceiling, forming a hallway at one end of the machining department.

Like an Olympic pole vaulter, Sutts maneuvers the eighteen foot tube into the cut-off lathe. The build sheet says that my seat tube is to be 16.5″ long, which is exactly where Sutts cuts it, and in to the box it goes. When he’s done, there are nine straight sections of tubing and a pair of drop outs.

I’m not a machinist, but this first step seems far easier than what comes next, which is the tube butting process. By making an already thin tube wall even thinner, the ride characteristic of the tube is changed. For a given diameter, a thinner tube wall will yield a more compliant ride. My bike already has cushy tires and a plush suspension fork, but even still, I’ll appreciate the give these butted tubes will provide. Each individual tube is butted for the individual rider. Your bike and my bike could end up with the exact same tube diameters, but the wall thickness will almost certainly be different, and so will the resulting ride.

After butting, the tubes start taking shape. The down tube gets curved to create enough clearance for the fork’s crown to pass underneath without contact. I will crash this beautiful bike. This I know. And there will be damage to my components and my pride, but not to the underside of my down tube.

In order to fit one tube precisely to the next, Sutts copes the ends of each.

On our full titanium frames, we give the chain and seat stays an “S” bend. Stays are bent two at a time in a hydraulic press at room temperature. When each bend is complete, they are inspected on the alignment table to make sure the bends are accurate. The chain stays also receive a squish, in my case a big squish, to achieve clearance for a burly tire.

My chain stays are 17.2″ long, will accept a 2.4″ tire on a 27.5″ wheel, and will allow clearance for my 32 tooth chain ring. You can probably imagine that there are a few thousand variations on chain stay designs. I find it fascinating.

The finish line of the machining process is the jig, where the frame builder can see his or her work come together. Once the jig is mocked up to the appropriate angles and measurements, each piece of my frame is put into place. For the very first time, and only for a shining moment, the shape of the frame is revealed.

If you listen carefully, you can hear the beautiful sounds of a far away choir, at least I think I can. The jig rolls to welding, and I pace with excitement.

Underway

When we receive a signed confirmation form for a new bike, the designer staples the pages together, slips them in a folder with all the accumulated paperwork, and clicks it off in the database as “confirmed.” That designation alerts Matt O’Keefe, the head of production, who nabs the folder and walks it back to the machining area where he files it neatly and squarely in the back of the build queue. The last spot in the queue can be found all the way to the right of the vertical file.

If thinking about your new, one-of-a-kind, hand built Seven Sola SL gets you excited, well then, you want that folder to be all the way to the left. Until it’s the very first one on the left, it won’t be started. The wait can be agonizing.

So I couldn’t believe what happened this morning. All alone in pole position, my folder finally sat on the far left.

From there, right in the sweet spot, Mike Salvatore plucked it out of the queue, then invited me into his office to show me the build sheet he was creating for my bike. I glowed.

The first task is to take the information from the confirmation form, and turn it into a build sheet that specifies every detail of the work to be done. Every single detail, big and small. Tube lengths, diameters, wall thicknesses specified to thousandths of an inch, cable stop styles and locations, where the tubes will be cut, butted, coped and many, many other pieces of information are all included on the drawing so that it can flow through the fabrication process without being held up.

Mike has drafted several thousand build sheets, but I could tell by the confident clicking of his mouse, this one was extra special.

Reading my enthusiasm, he pointed out a few details and explained why they were important. The chain stays, for example, when designed around my single 32-tooth chain ring and 2.4″ tires have to be curved to avoid running into the crank, squished to create tire clearance, angled back to avoid hitting my heels, flared to miss the 180mm rear disc rotor, and finally spread to reach the drop outs. A lot of thought goes into each chain stay, a lot of engineering. After plugging in a few more numbers, every last specification was accounted for and the fabrication of the frame could begin.

For one lucky individual, this will happen in a matter of moments.