I have a confession. I have been coveting some triathlon-related gear. The biggest of which is a SRAM RED crankset, 165mm, 10 speed, GXP, 53-39T. Anyone have a spare one of those layin around? I'll trade you for the exact same thing except with 172.5mm cranks. Tweet me if you do.
The engineering mind in me got to thinking. Surely I could make my own version of the Torpedo mount for just the cost of some lightweight, stiff material and my own time. I recruited my brother to help me since he has access to scrap carbon and knowledge about machining things. His girlfriend found me a piece of scrap carbon, and on the day after Christmas we put our heads together and got to work.
|My brother teaching me UniGraphics at our kitchen table. Photo by Mom.
|Screenshots from UniGraphics.
|The template, cutting it out, finished template, finished tracing!
|Me drilling, Steven band-sawing.
When I got back to St. Louis (and let several months go by), it was time to sand these suckers into submission. Mwahahahaha. First I started with 100-grit paper to get all the big chunks off. I used a chopstick to help force the paper into the small slots. Then did the same thing with 220-grit and 400-grit, in that order.
|Sanded on the left, unsanded on the right. Back and front shots.
Then, it was time to put on a finishing coat. Although, I gotta admit, I was too dang excited to try this out so I mounted the sanded-but-not-coated piece onto my bike for an easy Saturday spin. I had to add a little bit of bar tape (lucky I had extra laying around) under the lower velcro straps so they would be more stable. And I had to steal a decidedly un-fast-looking plastic bottle cage from my mountain bike (complete with residual dirt). But I confirmed that the dimensions all line up, the velcro holds pretty well, and the piece will not break under training stress.
|First installation, with a dirty mtb cage.
After that first ride, I purchased a carbon bottle cage for aesthetic purposes (it's my bike that's vain, not me) and then decided to put a different final coat on each piece. For one piece, I used a 5min clear epoxy. On the other, I used a spray-on clear coat. I discovered my epoxy-ing skills are severely lacking; I ended up wasting quite a bit and the finished product still looks a little goopy and uneven. But it is very shiny and feels durable. The spray clear coat was ridiculously easy to apply but the finish is thinner and looks like it might wear off more quickly.
|Final install! Photo from underneath the aero bars.
I chose to install the clear-coated piece because it looked cleaner.
|New bottle cage! Ready for racing!
I proved myself right with this project, that the X-Lab Torpedo mount really is just a piece of carbon with some holes cut into it. And it can be made at home. But it took a significant amount of time, way more than $50 worth, to create this thing. It took design time on the computer, fab time in my grandpa's shop and in my apartment, and shopping time in a hardware store for the screws/washers/nuts/velcro/epoxy/clear coat. Granted, I had a learning curve on the design software and epoxy finishing, but it still was a multi-step project that consumed several hours. So if you don't have access to free scrap carbon, or a bandsaw, you are probably better off just buying one from your local LBS. And then you won't have a goopy epoxy job to deal with!