I've been wondering, how did they make the Profile cranks wrap around the threaded & splined bosses at each end ? What is this construction technique that they use ?


Oh look... someone even took the wrap idea and applied it to the headtube of a frame. Pieces of the downtube continue past the headtube and are wrapped around the front and welded. He got the idea from Profile crank arms. Very unique !


How about a wrap handlebar ! Anyone knows how ?

Profile's new catalog has a step by step showing how they make their cranks. There is also a video on the Best of 2004 DVD by Transit.

Basically the tube is mitered for the bosses. the ends are wrapped around and fully welded. the weld at the end of the bosses are ground smooth.

Thanks Special Ed

thinking of makin some? just make sure they are marked up as repros dude (I'd take some original '82-83 box style if you do em !)

I don't know about Profile but when I got the 50 cent tour of Bullseye back-in-the-day they were welding a boss in place and then having it "broached". I'm no engineer but most likely it was done in this manner to keep the splines from getting tweaked during welding and cause possible binding. I'm thinking they also broached the arms post-welding to get the alignment of the splines perfect...so the arms would be exactly 180 degress apart.

Just curious... would it be a good idea if someone actually took the wrap idea and applied it to the toptube/seattube junction ? Pieces of the toptube continue past the seattube and are wrapped around the end and welded ! Seem interesting huh ?