Originally Posted by Doge

For one - weighting fore and aft. On a decent, the weight will be farther back. There are generally speed differences entering and exiting as well. Of course the approach is different. The descender is often braking before the corner throwing weight on the front. Yea I know the pavement was slippery but I doubt Lace would have been doing his cross country trip if Beloki didn't have a corner in front of him - on a decent.

If the corner is also descending/negative grade, you have the exact same centripetal force (v^2/r) but less friction, as the weight on the tires is less so you cannot lean as hard as if the corner were level, for the same reason a sports car can break much shorter distances going up hill than down hill.