Anyone build their own frames?

[graucho]

Not a pro at bike frames, mostly have done mini choppers. I purcheasd some bender plans cheap from ebay. They say you can build in a few hrs, took me a saturday.
http://cgi.ebay.com/ebaymotors/EASY...36442QQrdZ1QQsspagenameZWDVW#ebayphotohosting

Also got rid of my torches and arc welder years ago when I stopped building street rods.. Purchaced 110v mig from ebay also to do the thin stuff. Took some practice, works great on frames.

 

[lennyharp]

I use 4130 Cro Moly Seamless tubing if possible for my bike frames and trailers. The frame work I built to handle the Staton gearbox and EHO35 Subaru motor is .049 wall thickness 1/2 inch tubing I got from Tube Service downtown Phoenix. I have bought from Nova Cycle Supply and the tube sets are great if you want to build a complete frame. They have bottom brackets, braze ons, head tubes, drop outs and all the fittings needed as well as many tubings. Probably need at least the Mountain bike or tandem tubes as road bike stuff is so thin it would not hold up to motored bike use. Here are some tables with common bicycle steel sizes for 4130 ....... http://www.fairing.com/bicycle_frame_depot.asp?subcat=cm4

 

[SimpleSimon]

Great thread. I have been working on and tweaking a bicycle design for most of a year, after spending more than 6 months learning the basics of steering geometry, ergonomic design as applied to bicycles, etc. Practical design work has been frustrating at times, but very interesting, and the info here will be a very real help. Thanks to all of the contributors to this thread.

 

[lennyharp]

I find the geometry a facinating part of the design process. Seems there are a lot of ways to look at what is desired. I look at the motored bike as a performance bike that needs performance built into the frame angles. The frame I think can be longer than a racing bike but it probably needs angles a lot like the racing bikes. I am going to extend a frame to have about 15 extra inches in the rear end from bottom bracket to rear hub. I will probably just cut off the rear end and rebuild it to my specs.

I will use the angles that a racing mountain bike use as it is designed to go 50 miles an hour down trails and keep control easy for a tired racer. I am using a racing frame right now and find it works great. I will be shooting for head angle 72% seat tube angle 72-73% bb heights 11.5-12 inches chain stay length about 32 inches. There are lots of measurments and angles to take into consideration, http://www.surlybikes.com/bigdummy.html shows a specs sheet for their bike. This is not a race length but the angles are straight from racing bikes. All I can do is try and see if my theories work out.

Augidog is using this stretched out frame design, but I don't know any measurements or angles he used. I started building frames in the 1980s when mountain bike design developed. The changes that took place and interesting geometries used was an education for me.

 

[SimpleSimon]

Well, rats.

I had a long post finished, hit submit, and it evaporated.

I'm not going to re-write it. Suffice it to say, I need a trike. I want a tadpole for various reasons, and I want it to be a leaner for those same reasons. Semi-recumbent I need. Nobody I can find builds one, except some of the forward spar mounted crank recumbents, which for various reasons don't work for me, and they are all ****ably expensive.

So, I've designed one. I'm about ready to begin building it, which means I need to find shop space I can use (at least a garage), and I need to do so soon. Money is the biggest limiter - disability income doesn't go far. Material costs will run about $700, depends on how much I can salvage.

 

[fm2200]

my experience with welding and fabricating a frame for motorized bikes was ok but they were weren't works of art, kind of utility looking. Now in my opinion you'd be hard pressed to make a better looking frame than what's out there now like the Schwinn old style frames the kind China's reproducing for these gas bikes like the one's sold by spookytooth cycles. I have an all chrome frame and you could never afford to chrome plate a frame after fabricating one, and to make a better looking frame is doubt full. Unless of course you think, you are the a legendary designer with a flair for artistic ability and innovated one of a kind concept, then you just may pull it off. For me I'm really satisfied with the old style Schwinn that I have from spookytooth.