Handbuilt Titanium 29er Mountain Bike
For those of you following my blog these past few months, you know that I’ve been going to the United Bicycle Institute (UBI) to learn not only how to work on bicycles as a mechanic, but also to learn how to build frames.
I’ve gone one class left, but I’m far enough along now that I can honestly say that I’ve completely built my own bike. In this case, a mountain bike frame made of titanium tubing, joined by TIG welding (a new skill for me), custom built to my own specifications.
It is what’s known as a 29er mountain bike, built around 29-inch wheels. Traditionally, mountain bikes had 26-inch wheels (click this link to see the size difference) but a few years ago some smart folks decided to make the wheels as large as a standard road bicycle (29″/700C). There are advantages (as well as some disadvantages) to the larger size, but since I already have a 14 year old 26″ mountain bike, it was time to try out the “new” technology.
Not only is the titanium frame completely built by me, but so are the wheels. Custom made for this purpose. That’s another skill I learned at UBI. These wheels gave me fits that we didn’t encounter in school, but with the skills I learned, I figured out how to overcome the issues and turn out two pretty darn perfect wheels. The last set I built was for my road bicycle, which doesn’t have to deal with the impacts and forces that these will have to endure. For the first few weeks, I’ll cringe just a bit as I bash these through the rocks, over the roots and off jumps.
The color scheme was really dictated by my front shock. It was the end of season sales, so I jumped on a great deal before class even started. As you’ll see in a moment, it’s aluminum, white, black and red.
The black and red work really, really well with the bare titanium frame.
Don’t you think?
And before someone gives me a hard time about mismatched front and rear tires (you know who you are), after discussing with a local bike shop owner, I bought the Continental Mountain King 2.4’s, knowing that they run small, much closer to a 2.2. When we built the bike we measured and figured that 2.2′s would fit fine in the rear triangle. Well, a few mis-strokes of the file and some other decisions along the way, plus the fact that the titanium pulls like crazy when it’s heated and that almost-2.2 tire needed at least another 2mm of clearance on the knobs for it to work.
Since it’s a small independently owned shop, he wasn’t as keen as I to swap out the entire set just so I could have matching tires; I understand that. So for now I’m running a 2.4 with very aggressive knobs up front (where I personally want them) and a less aggressive 2.1 in back.
The three pics immediately above were taken right before the yesterday’s maiden run up the fire road and back down the singletrack. I picked my path purposefully to not be too technical, since there was a lot I needed to get used to. For one, the bike is an upgrade from my 26” mountain bike that I bought in 1999, so these wheels were going to accelerate and roll across obstacles differently. Plus, the handlebars are a good 200mm (almost 8”) wider, so I needed to get used to those before I hit the narrow paths between the trees. Also, the SRAM X7 drivetrain shifting is quite a bit different than my 15 year old Shimano XT drivetrain.
So best to go (somewhat) gentle while I work things out.
Not two minutes into the downhill portion of the run, the bike showed me who’s boss. It will take a few days for the skin from my hip to ankle to return.
But I can’t wait to ride it again.
- Handbuilt titanium frame – .035 tubing; 74° Seat Tube; 70° Head Tube; Effective Top Tube Length – 630mm; Bottom Bracket Drop 58mm; Chainstay Length 450mm
- Handbuilt wheels – Shimano XT M629 Centerlock hubs; Sapim Race 2.0/1.8/2.0 Double Butted Black Spokes; DT Swiss M520 29″ Disc Rims
- Fork – Manitou Tower Pro – 120mm of travel
- Headset – Chris King Red Sotto Voce
- Stem – Spank Spike 50mm, 0° rise
- Handlebar – Spank Spike EVO 777mm
- Disc Brakes – Shimano SLX; Centerlock hub mount; 160mm rotors
- Drivetrain – SRAM X7, 3×10 (yes, that’s 30 separate speeds, although it really means that there are ~24 usable gears). There are five gear combinations that are between 1:1 (22×22) and 1:0.61 (22×36). Those sure made riding up the steeper parts of the fire road more comfortable.
- Seatpost – FSA SL-K Carbon Fiber, 0° offset
- Saddle – Diety Pinner Downhill
Huge thanks to Mike DeSalvo (who, other than Goddess, is the only one to see this bike in person so far) and Rich Arvizo (UBI) for getting me through the frame build. I’m already looking forward to the steel TIG class in March.