link belt conversion-10K

All - Hi. I put a link belt (and earlier, a serpentine belt) on my underslung-motor 10K. I also made a .200 wide split flange to keep the belt from slipping off the motor pulley. While I've read that guys say the flat belt to link-belt conversion gives "geared head' performance, I'm able to cut cast iron at .0033/rev with the link belt, on the large spindle pulley and the small motor pulley, at only .025 deep/side on a 3" diameter. I'd hardly call that geared head performance. It also chatters.

Can someone calibrate me? Am I expecting too much?

Thanks