Sunday, May 08, 2011

Messing around

I love making and repairing things, love working on bikes, and recently decided my road bike was a bit too small. Guess who is going to learn to make bike frames.

I am 6' 4" with a 96cm inseam, so I need a fairly gargantuan ride. I have an old 62cm 1973 Nishiki Semi-Pro that I have converted to a commuter that is quite comfortable, rides smooth as butter, and climbs easily with a heavy load. Unfortunately it also weighs as much as a small car and is ugly as sin.
By the way, this frame was designed for 27" wheels, so has longer chainstays than current road bikes, making it awesome for carrying bags and still having lots of heel clearance. And if you convert the wheels to 700c, you have a ton of space for big comfy touring tires! I have 32's on there now but could easily go a couple sizes bigger. The only problem is that you need some long reach brakes, but Tektro makes the R556 long reach calipers that work perfectly. In fact, I think these things are way better than cantilevers which is what is normally on touring/commuter bikes, and they provide plenty of clearance for large tires and fenders if used on a 27" to 700c conversion:


I added braze-ons for racks and cable stops for different cable routing, and it turned out pretty sweet. The top tube on this bike is nearly 61cm center to center, which is quite long, but seems to fit me really well. However, with the 62cm frame size I have to use a stem with a large rise to get the handlebars up in a comfortable range. Standover height is nice, it could be taller in this regard but I like a little extra room..

So......how the hell did I get so sidetracked here? What was I going to talk about? Oh yeah, I want to build a road frame that has a standover height not much more than my Nishiki, but with a tall headtube so I don't have to use a crazy amount of spacers to get the handlebars up (approximately 1.5 to 2 inch drop.) I wanted it to be kind of a classic looking lugged steel frame, but with a more modern "compact" geometry. I wanted it light but also not too flexy considering how big its going to have to be. Turns out the perfect lug set exists already, the Llewellyn XL compact road set:



These things use a 31.8mm top tube and seat tube, and a 35mm down tube. Head tube size is 36mm. They give you 73 degree seat and head tube angles and a 6 degree sloping top tube.

I put my rusty drafting skills to use (thanks Mr. Kenoyer) and drew up my full size drawing. Took several drafts before I got everything to fit just right. This sucker is going to have a 61cm center to center seat tube, an effective top tube length of 60.5cm, a 240mm head tube, 75mm bottom bracket drop, and 425mm chainstays. Instead of building a fork, I designed it around the IRD Mosaic 57 carbon fork, which has an extra long steerer so will work well with my long headtube.

To keep this beast light and reasonably rigid (but not harshly so) I ordered a fairly nice "double oversize" tubeset (Columbus Life). Got the set and all the small parts I'll need from Nova Cycles. My hope is that with my frame size these tubes will offer a little more stability and rigidity but still have that nice smooth snappy feel that you can get with steel.Can't wait to get started!

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