I am building an 0n30 layout incorporating a reasonably steep incline which my two Shays both climb comfortably with no slipping. However, when descending, each loco displays some jerkiness.  They are both DCC controlled using the NCE system.
Has anyone else experienced this and are there any solutions?
Rebuilding the incline is not an option I want to explore as it would result in a major redesign of my layout.

As a returnee to the Model Rail hobby in the UK I've just bought a DCC Ready 0n30 Shay at a very good,almost silly, price on e-bay from the Favourite Spot. It's a loco I've always admired for it's unique appearance and am pleased now to own such a model. However Bachmann apparently expect buyers to know everything about their purchase as they do not include any detailed instructions. I assume it is 12 volt but there's nothing to confirm this. In the box was an exploded diagram detailing all the bits but which ignores  the chip/circuit board visible in the bunker. Neither does it show where the plug point might be for adding a DCC decoder. Perhaps I'm expecting too much from the Makers but can anybody provide me with this info please or tell me where I might get it?