Road Bike Handling: Stem-Length/Trail relationship?

Triathlon Forum
1

Some manufactures, such as Colnago, use a large trail and a short top tube - and therefore long stem. Others , such as Trek use a small trail.

Is there some combination of stem length and trail that is unacceptable for a road bike meant to be ridden fast? For example would Calfee with a 58.8mm trail and a short stem ride poorly(unaggressively)? Or a Trek with a 50mm trail and 80mm stem? It seems as though a large trail would need a shortish top tube to get your weight over the front tire to give it a race feel. If I lived in SoCal I would just go test ride all these combinations but it ain’t gonna happen where I live.

Any theories?

2

I read something about this one time but can’t find the url. Seems to me that the moral of the story was to try to run a stem that is neither too long >140mm nor to short <80mm which means optimizing your top tube length. A short stem makes a bike twitchy and a long stem makes it unresponsive.