Originally Posted by
jppe
Has anyone using a “frame too small” experienced a shimmy on fast descents? Just wondering if that could be a factor as well. Those can be frightening!
My larger frame road bike (Centurion Ironman) felt a bit twitchy on fast descents and curves when I first swapped from the original 125mm stem to a 90mm. But I got accustomed to it quickly. The overall frame geometry is more oriented toward comfort and stability in long road races or time trials, so that offset the slight twitchy feeling.
My smaller frame bike (early '90s Trek 5900) has the original long Ibis titanium stem. I suspect the bike might feel a bit twitchy with a shorter stem. It feels a bit stretched out until my back, neck and shoulders are loosened up. But it feels very stable on fast descents and curves. The LBS owner remembers those early Trek carbon fiber bikes and said they were more oriented toward long one day and multi-day stage races and time trials, and some racers found them a bit unresponsive for crits on short courses with lots of tight turns. No big deal, I'm never riding crits again at my age. Time trials, maybe.