iamlucky13

Several classmates and I went on a tour of an aluminum extrusion plant today that will be giving us some assistance with our senior design project. The company is SAPA International, which is based in Sweden, but their American office is here in Portland, OR. They are the 3rd largest producer of aluminum extrusions in the world. A couple of their engineers gave us a very interesting and thorough tour of the plant. I didn't even know before the tour started, but it turns out they have a division at this plant for manufacturing bicycle frames for several different companies (score!).

Needless to say, that was the coolest part of the tour. When we walked into that building I could see boxes packed with some neat-looking anodized rear triangles that I instantly recognized as being part of Santa Cruz Blurs. It appears their VPP frames are mostly or perhaps entirely produced here. Our guide took us through the entire process. We had already seen the extrusion process earlier in the tour, so he showed us tube-cutting, butting, welding, alignment, shot-peening, heat-treating, and anodizing. In particular, they seemed to be doing a run of Ellsworth Truth frame welding that day. There were several alignment steps that were very interesting and resulted in final tolerances of less than 0.004 inches (0.1 mm)! My professor commented afterwards that he finally understood why high-end bikes cost so much now that he had seen all the work that went into them.

I don't know all the companies they make frames for, but they claim you can tell by the large laps on their TIG welds. I did for sure see multiple frames for Santa Cruz (Blur, Blur 4x, VP-free), Turner (5-spot and DHR), and Ellsworth (Truth and a couple of their beefier frames). None of these had decals or badges on them, so I was struggling to ID them all. I also saw some sort of monocoque DH bike I didn't recognize, some BMX frames, and a few copies of what looked like an aluminum time trials bike. A lot of the assembly workers seemed to be into riding, as many were wearing T-shirts for the various brands.

So, that's a quick summary of a really great tour. If anybody has any questions about some of the manufacturing steps or aluminum extrusion in general, I would love to share what I saw in detail. I'm afraid I didn't have my camera, so there's no pictures. I offered to take a few of the reject frames off their hands, but no dice.

FoX Rider

Sounds like a really fun time. I would love to get out of school to see how bikes are made. LUCKY LUCKY LUCKY

anthonaut

Yes, you are lucky13! That would be an awesome experience.

Nice try with the reject frames

iamlucky13

I think any mechanically inclined person would really like this tour regardless of their interest in bikes.

Aside from the obvious awesomeness of seeing frames welded together and lot's of fresh blue anodizing on Blur frames, the extrusion process for the tubes themselves was pretty cool. In particular, we spent a little extra time watching their 10" press in action. They were feeding 10" diameter aluminum "logs" that were about 30 feet long into the furnace. It would come out at 850 degrees F, which was hot enough to make it pliable, but not molten. Then a massive shear would chop off about a 6 foot section which was hydraulic loaded into the ram, shaking the concrete floor with each movement. The ram was simply a huge hydraulic press that exerts about 3000 tons of force on the aluminum, forcing it through the die as a continuous cross-section about 100' long that is immediately cooled. This press was making some sort of rail, but the bike tubes are made the same way on a smaller 6" diameter press.