Well, I'm reviving a 15 month old thread because I've been playing around with rigid Future Shock replacements on my Specialized Sirrus X 5.0. I initially bought one of the ultralight Ebay units described earlier in this thread, but despite the finite element analysis provided, the 2mm wall thickness just weirded me out a bit, so I decided to fire up the lathe in my garage and crank out one of my own. The much greater wall thickness as shown below is comparable to that used in the initial FSD kit developed by the Bike Sauce:




Basically I just bought a 1-1/4" rod of 7075 aluminum, cut it down to 150mm, turned a couple of outer diameters to fit headset and stem then bored a 3/4" hole down the center - raw material and finished product shown:



Another reason to do this is to fit the stem I want to use which has a slightly larger than usual stack of 45mm. The end result fits well.


The thicker walls do come with a weight penalty - my replacement shaft weighs 170g, similar to the Bike Sauce unit but much heavier than the Ebay unit at 110g. Though it may damage my weight weenie credentials I'm willing to sacrifice the 60g for increased confidence bashing around on mixed terrain.