Introduces argon into the frame and absorbs heat from the weld to reduce distortion; results vary based on tubing diameters, wall thicknesses, and personal welding styles.
Compatibility:
Specifically sized to fit our shells with a 1.860" center relief
Metal to metal interfaces are bronze to stainless steel making sticking, binding or galling very unlikely
If you already own our heatsink FT5004, you only need to buy the bronze center, FT5019, and draw bolt, FT5029; the rest of the pieces in the assembly are interchangeable.
Components:
Center: C-630 bronze (very good heat conductor)
Cones: 303 stainless steel
The center expands with two cones to fit with minimal clearance on the interior diameter of the bottom bracket shell. One cone butts against the draw bolt and the other is threaded female 1/4" NPT for the argon connection
Draw Bolt: C-630 bronze
Drilled to accept argon from the threaded cone. It has an internal hexagon to accept both a 5/16" and 8 mm Allen wrench
Washers:
Two 1-7/8" OD stainless steel washers plug both ends of the bottom bracket shell and are pulled together with two M20 x 1.5 nuts.
Item sold as an 8 piece assembly.
Directions for Use
After the frame has been tacked, remove from the fixture.
Insert the bronze expanding sleeve into the bottom bracket shell. The sleeve must be compressed slightly to get it in the shell.
Place both cones in the sleeve.
Insert bronze draw bolt through one cone and thread it into the cone on the opposite side.
Using the 8 mm internal hexagon in the bolt, tighten the bolt which will expand the sleeve.
Install both washers with the mating nuts.
Introduce Argon through the connector (not included; the connector fits inside a standard 1/4" internal pipe thread in the cone).
To remove the heatsink, reverse the above procedure.