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What/Who's bike is this?
I wonder why they chose to create a welded rocker link; compared to creating one via CNC machine.
Warpage, tighter tolerances come to mind
I love watching the little refinements with each version.
(Sorry I couldn’t post the images properly)
I could be wrong though
Neko Mullaly from Frameworks video "I've bent a lot of shock bolts because I think because the link is flexing and the span of the bolt is too long"
Dis-engage pedant mode (not really, that's my secret Cap.....I'm always pedantic).
https://www.youtube.com/watch?v=9FkAP7k_CbA
Went back to the (second) In Depth video and it's a standard allen bolt with a standard thread length (for the given bolt length). It looks like it's an M6 bolt? I'm going to go with an M6 bolt as it doesn't seem like it's an M8 and a lot of bikes use a size 5 allen wrench for the shock bolts, which means an M6 bolt for a standard allen bolt.
Anywho, the bend looks to be right where the thread starts. Coincidence? Nope. That M6 bolt with the fi6 mm shank? Yeah, that's more or less a fi5 mm diameter cross section when you factor in the thread being cut into the 6 mm nominal diameter. Same goes for the relief in the shank to be able to roll the thread and all.
So that shiny 6 mm diameter bolt you have there? It's actually a 5 mm when you factor in the lowest load carrying diameter. Which, looking at it from a stiffness perspective, is less than half than with a 6 mm cross section - the second moment of area is defined by diameter to the power of 4, so 5^4/6^4 comes out at 0,482 (48,2 %). Taking the standard defined inner diameter for an M6 thread that is ~4,9 mm (diddly squat at first sight)? It drops to 44,5 %.
If it was an M5 bolt with the smaller diameter of 4 mm, then the stiffness value at the threads drops to ~40 % of the shank diameter.
https://en.wikipedia.org/wiki/Second_moment_of_area
https://en.wikipedia.org/wiki/List_of_second_moments_of_area
https://amesweb.info/Screws/metric-thread-dimensions-calculator.aspx
Looking at the last link, the minimum thread root diameter is even lower at 4,5 mm than what I looked up in my handbook, where the bolt diameter was equated to the inner nut diameter. This page does it properly including the tolerances. Obviously a 4,5 mm diameter makes things worse for the stiffness.
Having a custom made bolt with a 6 mm seat in the rocker before starting the M6 thread would likely help a lot.
Am I offtopic again?
Little bit, that's why we love you.
Williams racing makes a 200mm, mullet link for the Norco.