I tried running trains for the first time today and encountered very noisy running conditions on only some of my track. Here's what I'm using: All Atlas Code 55 Flex for the straight sections Snap track for the curves #5 turnouts I tried all three of my new engines today for the first time (just started a new layout). All track is glued to cork roadbed over 2" rigid foam insulation on an L-girder frame. Engines: Atlas SD-24 Atlas GP-38 Kato P42 (Acela) All three engines were noisy only on the curved snap track. So far I have only used 18.75 radius curved snap track in two areas with about 4' of flex and some turnouts between them. When the engines hit the curves the noise level is ten times louder over what it is in the straight area. It's as though the flanges are hitting the little molded spikes on the inside of the rails. Is this normal for Atlas snap track? If so, should I stop being a lazy newbie and use all flex everywhere, or am I missing something?