One of the major moans about this jump into RTR modelling is that things that should work together...don't. Case in point is this standard Bachmann 03. It runs beautifully, far better than I could manage with a kit-built chassis. It comes complete with tension lock couplers, as they all do, which are designed, one assumes, to work with the trade's uncoupling ramps. This is another gripe, but my point here is that this little beast runs up to a ramp, and then 'clunk'! There is a cover over the gear wheel which is lower than the coupling droppers. Why? Did someone fail to notice this at the design stage? So I removed the couplers and keeper plate, and with a BIG file ground the cover off thus exposing the gear as above which is now proud by no more than 1mm. Result: the 03 glides across the ramps like John Sergent on ice.