In the last segment the crew of U.S. Choppers straightened the Bonne Belle, 1940 45 frame, but I asked Rick Krost, da boss, if he felt any gusseting was necessary. He pointed out all the strong factory gusseting in the front and even on the single down tube, but suggested that we gusset the rear legs to strengthen the point as which the power hits the salt. My concern was in many respect for Valerie Thompson, our Bonneville Salt Flat rider.
I could tell, while working with Rick, and witnessing his watery blood shot eyes that he was either coming down with something or hungover. His first rocking chair gusset notion met with mixed reviews.
First, I coped the pipe after fitting it all to make sure it would all line up right and fit snuggly to the rear frame rails,” said Rick Krost. “I compounded the top “fish lips” by running the mill head at an angle… 25 degrees to be exact.”
It's real important to have the weld area clean before welding… nothing like emery cloth and elbow grease.
To make matters fun, these old frames are all furnace brazed. There’s brass everywhere on these frames. A lot of the times the pits in the metal keep you from cleaning all the brass out of the clean metal, which is bad for welding mild steels with 70S2 rod. It will contaminate your welds and they will fail.
“I chose to weld the pipe to the stanchions with steel,” Rick said. “and then weld it to the frame with Silicon bronze to avoid any contamination issues or weld failure.” Another benefit of SIB is that we can work around the tubing quicker as it has a lower melting point so as not to put too much heat into this old brazed frame..
”I used a clay heat sink in front of the castings or a sloppy wet rag,” Rick said, “depending, so the heat doesn't crawl over to that nice furnace brazing and loosen it!!! This could be bad!!!”
Done deal– the supports lined up well and were symmetrical. The 3/4 tube was used to help with any possible chain rubbing issues and they tuck up nicely between the frame rails.
Look at those rear frame rails. Notice how they line up and are parallel to each other? That was the frame fairy's work the other night…. boy is she good. “This frame was about 3/8-inch out of alignment, when we started this project,” Rick said. “U.S. Choppers putting old steel back into use again!”
“Hey Bandit, come down with this flu…,” Rick sniveled, “I'm outta here… go cuddle up to my wife and her girlfriends. It's 8:00pm and I'm hoping your liking the finished result.”
He only uses Proto-Fab tubing. It is seemless, cold rolled and drawn over a mandrel bender. No seems or scale that must be removed. “All size increments will slip-fit over the next size,” Rick said, “so no machining was required.” He welded each piece with silicon bronze rod using a Lincoln TIG 355 battleship welder.
