Santa Creme has had a nasty rattle the last few months. I suspected the main link, took it out/lubed to no avail. A slight click/gap when lifting the rear.
So then maybe the shock? Its never had maintenance, the only change was flipping the chip. So I deflated it, and began to take it out. Front bolt popped right out, but the rear was very stubborn. Wha?
Rubber mallet escalated to wood and real hammer. And a slip plus chip to the white creme frame. 
No more white bikes.
I measured the diameter of the mount bolts, front was 0.795, rear 0.805. Hmm. So I sought OEM bolts for my frame but only found Titanium upgrades. Oooh! Oilslick!
https://betterbolts.com/
Mount bolts plus some link bolts were part of the package for $46 ship + tax.
So I learned of the hardware and processes used to put the shock on the bike, its generally called "shock mounting hardware". This video by the Lost.co was very useful
https://www.youtube.com/watch?v=9ScLQgoNgxU&t=928s
I ordered parts, a 22.2mm width was closest to my 22.0 requirement, THEN found the "lead buried" in the very end - go SMALL. So returned the 22.2 and got the proper 21.8 for my 2018 Santa Cruz Hightower V1 frame.
Another $22.
Re-assembly was easy. Along the way I compared weight of the Ti bolt vs the OEM steel - 8g lighter each.
