A well-known ski store in the SF Bay area just completed a "major tune" on my 2008/09 AC30's. These skis had not been tuned before. Back at home, I got out a straight-edge and a flashlight to shine from behind just to see how the the job turned out. I observed that the plastic bottom has a very slight concave shape vis-a-vis the steel edges. A sheet of normal copy paper won't fit into the gap between the straight-edge and the base, but real thin paper such as heat imaging cash register receipt paper just fits.
Is this small amount of concave likely to affect the performance of the skis as compared to completely flat?
The shop said the bottom edge bevel was done at 1 deg and the side edge at 2 deg. Shining the light behind the straight-edge on the bottom shows the bottom edge does have a very slight bevel. And for the side, my 2 deg side edge tuning tool does match up.
Overall, the tune looks good with wonderful burr-free sharp edges and a structured base. But as above, I am not sure if the slight concave bottom shape is significant enough to challenge the shop for a re-do.
Many thanks for your comments.
p.s. The tune was a $0 comp which I got as a sweetener to close the deal when I bought something else of significance from the store. So I probably am not on strong grounds to complain too much!