I'm considering building a lugged steel track frame for my first frame. It's not likely that I will be able to complete this project before summer time, as I've never brazed, or soldered in my life, never designed a bike frame and only have a little real life experience with measuring dimensions and angles accurately enough to build a roadworthy bicycle frame. I'm asking around and trying to figure out a way to learn a little more about these things first hand. Currently, I'm toying around with BikeCAD and looking at a couple websites to price tubing and lugs. I'm trying to figure out where to start with figuring out what angles/dimensions will be necessary and which lugs will suit tight geometry and short wheelbase. Anyone got any tips on the basic design phase of frame building?
One thing that crossed my mind is this: Up here in wet Wisconsin, I thought the stuff would build up a rusty surface within a couple months, and this would be hard to clean up, especially on the inside, when it came time to build. About how long is the "shelf life" of untreated Columbus Thron CroMo tubing?
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For instance, I am looking at bottom bracket shells, and the description reads "60.30x62.30x7.30(degrees symbol) angles, 30x17mm, oval chainstays, also Italian threaded" I believe the first two numbers refer to the angle in degrees between seat tube and down tube and between seat tube and chain stays, and I assume that 7.3 degrees is the angle of each chainstay. As for 30x17, I'm not sure. Is this the threading of the shell?
This is extremely confusing and awesome. I'm going to go measure my Peugeot PX10N which was recently destroyed to gain a better understanding of tubing lengths/angles.
Nessism
The tubes come coated with a rust preventative of some sort but you could always add more.
17x30 is in reference to the oval shape of the chain stays. I've seen these listed with slightly different dimensions but basically there is not much difference. Unfortunately, these ovals don't often fit into the bottom bracket perfectly thus it's common to pinch them in a vice to shape them a little to optimize the fit into the sockets.
Good luck with your project.
Peterpan1
You can't leave the tubes lying around in a humid area, but stored in the kind of environment you would store books or surplus clothes, they will be fine.
The way I learn to design stuff is to draw different versions. Like if you want to design a road racing frame, look at some good examples. Get as many numbers off existing frames as you can, manufacturers print their dimensions, and you can import pictures off the web into cad programs and flesh those out to scale. Get components in your CAD, measure real wheels and parts as you get them. At the same time study current rides you are comfortable on. Or take bikes for a ride at the local shop and whip out an angle finder and tape in the parl before turning them in. You will soon learn to the design secrets of the classics of your particular segment as well as the more adventurous designs.
You don't need bikecad for this. I use turbocad at the moment. I have a files for various parts, but I started out with nothign more than rough wheels, concentric circles really, and groups of parallel lines I could manipulate. You just need to know some basic cad moves: translational moves, rotations, snaps, and trims. All the build info comes easily off your drawing. As I get new parts I create a file for them so I can use them in further drawings.
When it comes to building you initially cut out each part in the main triangle, and TurboCAD gives me angles and lengths to perfect diemsions. As far as the rear triangle is concerned, the rear axle/drops position comes right off the drawing, but the exact parts still need to be bent and fit individually, whatever CAD you are using.
Also, I only bother to draw the profile view, the rear triangle is 3D, but it comes together from the tubes, the bends, the tire clearance etc... I don't need a drawing for it.
superhotbug
I would like to know if you consider track bike as a bike you ride on a circular track or a velodrome track, or are you looking to build a single speed direct drive bike?
mediccody
I'm hoping to build a frame which will be durable enough to commute regularly and ride on the street, but which has track dropouts so that I can occasionally use the nearby velodrome (when the weather permits). A steel, lugged track frame also seems simpler to build due to its lack of cable guides, front derailleur mount, water bottle braze-ons, rack and fender mounts, etc.
The last couple days I've been looking at lots of frame measurements online, primarily ones similar to the track/track-style frame I've been considering. I've been doing some doodling of frames based on those designs. I don't have any good metric rulers or one of those half-circle rulers for drawing angles (forgot what they are called) so that may be a first investment in this project. I should probably also liberate a copy of this TurboCAD. Is there any free CAD software out there which will do this basic frame design stuff?
I've also emailed an instructor in the welding program at my technical college and hopefully he can give me some more information about getting some hands-on practice with brazing before I try to put together a bicycle. Basically, it may be a few months before I even start this project, but I appreciate everyones' responses.