head tube weld distortion

Joined
Aug 31, 2019
Messages
4
Many of the designs here, TimberWolf and LodeRunner for example, call for welding the head tube to the HSS frame. I'm not saying that's a bad idea, not at all. However, my experience in the welding trade tells me the head tube will distort due to weld metal shrinkage and heat effects. Has anybody else found the distortion to be a problem?

My main concern is that the top and bottom bearing cups will not be parallel after cooling. Is the distortion enough to worry about? Will I have to machine the cups to get the bearings to work smoothly?
 
Joined
Jun 22, 2015
Messages
127
Location
Ontario
I've done a few of these now, and have never had a problem. The bearings do not see significant load or speed, so any minor misalignment from welding is inconsequential.
 
Joined
Apr 15, 2013
Messages
1,793
Location
Washington state
I purchased 2' lengths of 1 1/4" head tube material which is slightly thicker than on most bikes plus it is cromo. never had issue with blowing holes etc. since I have been using this headtube material (purchased online from shop in Oregon that sells bike frame materials. use a search to locate. I can't find my old bookmarks on this computer.
 
Joined
Nov 9, 2011
Messages
944
Location
Banglen, Thailand and a little bit Reading, UK
I do my builds in stainless, and some extortion is expected after welding. Simply filing them brings them back close enough to call parallel. Same goes with the BB shell. I use a couple of half metre lengths of square tube on each end to check for parallel. I also put some old bearing shells in the tubes whilst welding, just to keep them sort of round. There's enough slop in the cheapo bearing sets I use to not need perfect parallel faces, but each to their own....:)
 
Joined
May 31, 2013
Messages
2,374
Location
South Benfleet, Essex, England, UK
Spare "for welding" inserts, every time. ;)
 
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