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Tech Tips/ DIY

Building The Tapered Leg Springer

Article & Photos By: Will Ramsey

Originally Published In The March 2016 Issue Of Cycle Source Magazine

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In the Cycle Source Year In Review, the readers voted Faith Forgotten Chopper’s tapered leg springer Best New Product of the year. I’d like to repay the honor by giving everyone an inside view of what goes into producing one of these front ends. This will be a two part tech article. This month I will focus on some of the machining processes and the raw fabrication of the springer. The next installment will walk you through the assembly process and installation of a completed Faith Forgotten Chopper Springer Front End.

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Building a springer calls for a lot of machine work. Many of the parts in our springer are CNC machined DOM tubing to the length r e q u i r e d for our customer’ s front end. The precise length will be obtained in the lathe when the ends will be faced square. The unique taper is cut manually in the lathe. This is accomplished by offsetting the tailstock while running the material between centers. This has taken a great deal of time to perfect as it is not easy to turn a sixteen to twenty eight inch taper in a lathe without chatter. It is possible to I Article & Photos By: Will Ramsey by Brian Howell at Tooling Ventures in Louisville KY. He simply kills it on accuracy and surface finish for us.

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Our springers are built to order and they are built to fit, so some of the variable components are machined manually in house to provide a unique fit to the customers’ bike. The neck stem is one of these items. Accuracy is critical here as the bearing surface needs to be precise so that the front end isn’t sloppy.

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The rear legs are rough cut in the horizontal bandsaw from 1.250” DOM tubing to the length r e q u i r e d for our customer’ s front end. The precise length will be obtained in the lathe when the ends will be faced square.

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The unique taper is cut manually in the lathe. This is accomplished by offsetting the tailstock while running the material between centers. This has taken a great deal of time to perfect as it is not easy to turn a sixteen to twenty eight inch taper in a lathe without chatter. It is possible to use a taper attachment but it requires a lot of blending (with sandpaper) between stopping points. The method we use allows for a single accurate cut that cleans up very nicely. When it comes to surface finish, it is all about Feeds & Speeds *research project*

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Once the taper is cut I use a center drill to place a hole on the lower end of the tubing. This will be the location of the rosette weld (plug weld) for the lower inserts.

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*Trade Secret* I use a countersink bit in a hand drill to taper the rosette weld hole. This accomplishes two things. First, and most important, it makes is much easier to ensure full penetration and fusion between the insert and the tubing. Without the taper it is quite easy for the weld to “bridge” across the tubing trapping a void inside the weld. Second, it allows for a greater amount of surface area to be welded thus ensuring a strong rosette weld. This is a technique that should also be used when slugging a frame.

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The leg inserts are precisely machined to a light press fit. This ensures a strong, centered joint that cannot be skewed by the welding process. I hammer these into the legs with a rawhide mallet or a rubber dead blow (whichever happens to be closest to me)

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The rosette weld is performed first followed by the seam. In this case the order does not matter as any rotation of the insert is meaningless. However, if you happen to be slugging a frame the rosettes should always be welded first to aid in maintaining rotational alignment of the tubing during the welding of the seam. But I digress…

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The rear legs return to the lathe in order to metal finish the welded seams. I often find myself spotting poorly metal finished joints on aftermarket chromed parts where I can tell a grinder was used to speed up the process… Do yourself a favor and take care when dressing out a weld. Push yourself to be a better craftsman and you will be rewarded with a feeling of pride. Now I’m not saying a weld can’t be properly finished with a grinder; it is just my opinion that a file is king when it comes to dressing out the weld on a tube.

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The springer legs are sanded to a 600 grit finish in order to provide an excellent surface finish for final plating or powder coat. If a springer is welded up with a rough finish and sent out to be chrome or nickel plated, the ability to polish every inch of the product is compromised. I like to get the surface finish as nice as I can to ensure a beautiful finished product.

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With the weld dressed out and the leg sanded, it looks like it was machined as one solid piece. I am always inspired and driven by builders and craftsmen that take the extra step to really “finish the job”.

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The rear legs are finished by welding in a threaded bung which secures the top tree during final assembly.

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The legs are not the only parts to get sanded to a nice finish. The trees and spring perch must also be sanded with a DA sander to a 600 grit finish to allow for easy and complete polishing. This takes time but really makes a difference in the end. It is these extra steps that separate our parts from many high production products.

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A simple hydraulic press is used to press the neck stem into the lower tree before we can begin organizing all the parts in the weld fixture.

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This fixture is built on an aluminum cast jig plate. I designed it to be extremely accurate as all the components indicate onto 1/8” dowel pins and all mating surfaces are machined square and flat.

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The fixture rotates allowing me to always weld in the flat (horizontal) position. This simply makes laying down nice weld beads easier. After the parts are thoroughly cleaned with acetone, the springer is TIG welded using purified argon, ensuring the best possible welds.

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Our Mittler Brothers bender helps me crank out two very accurate wishbone legs for the front half of the springer.

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The fixture components are changed to position the 3/4” front legs prior to welding. This picture illustrates the care and precision used to produce a straight and accurate front end.

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After welding is complete, the springer is sent out for plating. Next month we will illustrate the final assembly process and mounting of a completed Faith Forgotten Choppers Tapered Leg Spring. Feel free to contact me with any questions comments or concerns. will@faithforgotten.com

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