Like most of you know, the shocks have a fair bit of sideways movement between the shaft and the shock housing.

Problem is that in testing it was found (mainly by Nik Weyers) that air gets in this way no matter which caps (alu/plastic) you run. We tested a number of different o-ring types ( original, low friction, aftermarket 801's 70sh ), but the problem remains.

I have some custom shaft guides in mine (the guide ring between the o-rings made to much closer tolerances), which helps a lot (!). But they do wear quickly. I rekon since it's used to take a strain they are not really designed for. So it's more of a "work around" than an actual solution.

I did a bit of playing around with some parts to get a good shock cartridge without needing hard to make custom parts. You just need to drill out the cartridge cover a bit. Now it doesn't build up rebound anymore and the shaft support is much more accurate.

Note 1: Yes you need to use the smaller yokomo shim (6,4mm) twice, your not using the larger ring (7mm)

Note 2: The AE o-ring will fit, but of course I'm using the Janus "801" O-rings

Update: 26.03.2014 - Yokomo fix
"X" Ver. II shock bottom cap (with stepped collor) for B-MAX2