PVD IS Head Tube
Most framebuilders that work with steel have ignored the newer integrated headset design. I belive that it is the future. I decided to make up some very special head tubes for my bike projects.
Design
Note the increased strength on the bottom side for extending far below the down tube when using larger forks.
Stock
The 4130 stock required for this part is very rare. 1.750 OD x .250 Wall.
I ended up ordering the stock from Factory Steel and Metal Supply Co. out of Detroit, MI. EMJ Metals out of Freemont would be another good choice.
The price was $18.70 per foot with a $20 cut charge from 20 foot lengths. A six foot section should be enough to get 14 x 4.5" tubes.
Machining
A bushing was required to hold the part during machining.
Finishing
Special cutters will be required to finish the frame post welding. Cane Creek P/N TL0100. A little under $200 for these babies.
End Product
The head tube came in a little heavy due to a few manual machining considerations and some mistakes I made in the process. I would expect that a perfect CNC version to weigh in at 125g.
Comparing this to a "standard" PVD light machined head tube (93g) and a Chris King 1 1/8" headset (98g), this design doesn't add any real weight but is a far superior design.
Upper Stack: 8.3mm Lower Stack: 0.4mm
On The Bike
Frame scheduled to be welded mid August.
