Code 100 Track Quandary -- Peco Compared to Atlas

[RobertInOntario]

Is it possible that Altas's Code 100 track is a fraction finer than Peco's Code 100?

I'm thinking this is the case because one of my older British locos (a Triang 08 diesel switcher, made in the late-1950s or '60s) bounces and clicks along my Atlas Code 100 track because of its large flanges (pizza-cutter) wheels but runs well on my Peco Code 100 track.

I basically can't run it on Atlas Code 100 track but it's fine on Peco's. Thanks in advance for any feedback!

Thanks,
Rob