I did the Antipodal Suspension Upgrade too. I was in a rush, so didn't photograph anything; and I was away from my computer, so I didn't consult the excellent directions provided above. I used about one-and-a-half doorstops (the leftover bit is 25 mm). I didn't glue the two pieces together. The exposed part of the rubber is now 40 mm unloaded, and it compresses to 34 mm when I sit on the saddle.
I've ridden 28 miles on it so far, 18 of them in the last two hours. Comments? Well, for the first time, I'd have to say I didn't think about the suspension once! Never bottomed out, never pogo'd, didn't have any creaking noise.... Draw the conclusion of your choice; it seems I noticed nothng at all. Presumably I was, like Jur, in Suspension Nirvana.
Note, at one point, heading up West Side Hwy at about 17 mph, I hear the distinctive sound of a tire blowing out. It sounded like my rear wheel. I pulled over, anticipating that harsh bumping of rim on pavement. But I soon saw that both tires were (and are still) fully inflated. Bizarre; what could that sound have been? Never found out; must have been a passing car.
One more word to Jur and Pine Cone: Thanks!
Congrats to you too. It's a really a nice modification. Yan should really take note of it and change the specs of the bike to this. It's much better ride and should be cheaper too.
On the "bang" noise - I wonder if the doorstop/elastomer was not fully seated at first, then popped fully in while you were riding. It's that, or you had too many beans for lunch!
