Here is the big frame I mentioned in the other big bike thread that is going currently. It's a 67cm for a big dude. He has broken custom bikes and wanted something reliable and weight wasn't an issue. He is a strong guy and likes to climb but he is also an aggressive descender. We talked about disc brakes but he was firmly in the Ultegra camp so we stayed there. Modern DP brakes are awesome.

I used .9/.6/.9 on everything but the down tube (straight gauge) and stays. The head tube is a thick walled unit that I purchased in 1 meter lengths. We took in opinions from several people regarding the needs of the customer including what he had already been riding, what he had custom made and he also got a fit from a guy out his way in Cali.

We ended up coming up with something pretty normal. 73 seat, 73.5 head angle and a 670mm C/C square frame with 425 stays. I raised his BB a couple of MM due to long cranks.

Here is how it went. P.S. I also modded a vintage John Deere steering box for the Friday thread.

We started by being goofy for a few mins.


30 285 by frankthewelder, on Flickr

Here is a bad photo of a nice tool. I can measure the wall thickness and locate the transitions. I forgot what the paint means on the end of the tube.

I made a collar to go between the 35mm down tube and the 31.6 seat post. I welded the OD and added a few random holes for plug welds.


30 313 by frankthewelder, on Flickr

BB shell is vented. I grain it "with" on a belt sander with a scotchbrite belt to I can mark it with a caliper. Primitive, but I do many BB platforms.


30 315 by frankthewelder, on Flickr

It's 10" long.


30 316 by frankthewelder, on Flickr

I made the end of the top tube rectangle to fit against the seat tube. Remember, it's bigger than the seat tube.


30 322 by frankthewelder, on Flickr

Here is how I do it.


30 323 by frankthewelder, on Flickr

Mitre the seat tube end of the top tube first. It makes it easier to keep the tube indexed.


30 339 by frankthewelder, on Flickr

Dinner time. More in an hour or so.,