Thursday, May 22, 2008

First Things First

Before I build a swing bike, or any other bike I need to build a road bike to train on. After a month riding a TT like everywhere I know why most people don't them except for races. Sometimes it's hard to climb in the bull-horns, or there are time you would just like to sit up.

Next week I'm going to start building my road frame. This is one idea I have.

Since every bike is an experiment. I'm wanting to bend tubing on this one. Since I'm Still planning to ride across MO for the record, I'm planning on building this bike so I'm in the same position on the drops on this bike as I am on my bulhorns on my TT bike. However I know I'm going to have to comprimise something since I want a road bike. I still have some tweaking to do.

While I'm talking about training I went on my first hard ride of the season. I did a lot better than I did last year at this time.

I rode my bike to the ride, and back from the ride, so I went easy, but looking at the meat and potatoes I spent 36 minutes of my ride above 172bpm. That about right for the TNWC (Tuesday Night World Championships), but I did a lot of sitting in and not my usual never ending string of attacks . . . but I'll get there.


Anonymous said...

I took a brief glance at your frame image, and a couple of questions came to mind.
1. What is your BB drop from centerline of the hubs? Have you considered doing a life-size drawing of your dimensions, so you're able to check exact wheel with tires installed fit?
2. What material are you considering bending? Is that the most effiencient way to join those two points?
3. Are you sure you want that slack a head-tube angel on a TT bike?

It's an interesting design, but since many things have been done before, it might help to consider the reasons that different builders used certain techniques, and the materials they used.

CurbDestroyer Chronicles said...

The bottom bracket drop is 75mm (The dimension is under the down tube). It's really low because I like a low center of gravity, and I like sitting lower than most people in a paceline. If this bike works well I'll then go for 80mm.

I could get a full scale drawing done, but I've got 6 frames around here to take dimesions off of. And if I need to a can project the points in different views. I've done that and headed of problems before.

I'm going to build it out of straight gauge 4130 steel. My first bike are going to be experiments. This frame I'm going to experiement with bending tubes. I want to build some verticle compliance in this frame. Since the stiffest tube is the shortest tube, you can say the longer the tube, the more flexible. So instead of a straight line from A to B, I'm giving it an arch. I have to say I don't expect much, and I'm bending them more for experience, and the way it looks in this case.

I designed this frame to be a comprimise between conventional road geometry and time trial geometry. I've never had a bike That I didn't think cornered fast enough. What I do notice is stability. I'm building this bike to have stabilty. Hopefully a with 71.5 head angle I should be able to read a book while I ride. The fork I'm going to use is 45mm. I'm stuck with that. So I had to choose a head angle that gave me a trail that resulted in lots of stability.

I learn more from failing than I do not failing. So far everything I've done has worked out for me. So I'll keep pushing the envelope till I find out what is possible, and what's not. A lot of bicycle look exactly a like, it's just the paint and stickers that make them look different. Sure there are other easier joining methods and ideas's but as JFK put it.

"We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win"

I know why other builder do what they do. an over time there is a reason some things are built the way they are. There is a reason most frames have a 72 to 74 degree seat tube. after riding a TT bike around for a month I know why. I can better communicate these reasons . . . for example why you don't want a road bike with a 78 degree seat tube after actually having done it and built it, rather than borrowing from other people's work. I choose to explore, rather than just go down the beaten path when it makes sense to. Everybody can buy a tubeset and weld it together. All it takes is some practiced skill. What intersts me is the imagination. There is no imagination in just welding a tubeset together out of the box.

Well anyway. Stick around because next Friday I'm going to start work on the road bike. I'm going to make some adjustments to it . . . maybe some radical. . . . Won't that be fun.