The BOS Kirk2 1-Way is definitely a racer’s shock. The open-mode compression tune is relatively firm, and while we rammed most shocks full of volume spacers to get the desired level of progression during testing, this was as progressive with no spacers at all.
This will prevent mellower riders, or those with naturally progressive bikes, accessing full travel. For our needs, though, it was about right.
Off the top suppleness was pretty good, though it felt a little dead further into the travel.
Removing the air revealed a pretty high degree of friction compared to some of its peers, but it’s also to do with the rebound tune.
We found the beginning stroke rebound too fast, causing bucking on take-off, or after hitting bumps when seated.
Slowing down the rebound caused less sensitivity in the mid-end stroke because the rebound shims couldn’t open up enough to allow it to recover quickly in this part of the stroke.
The firm pedal mode makes it an efficient climber and our rebound woes would be lessened if we could run it even more progressively, but most riders will find it lacking in sensitivity.