I am currently riding a 52cm Cannondale Supersix Evo and I am very comfortable riding the bike no problems with pain etc. I started out using a 90mm stem and now that I am use to it and a little more flexible I am thinking in my mind I could move to a 100mm stem or longer. One thing I noticed is when I am standing I can brush me knees against my bars so I thinking I may need to push them out a little bit. Any thoughts on going from a 90 to 100mm. Appreciate anyone's experience and thoughts.

The key to having the right stem length lies in your shoulders. If a rider develops some tension in their neck and shoulder muscles, that often indicates that the stem is too long. If you currently feel somewhat cramped, then I can't think of any reason why you shouldn't go longer. Otherwise, if your position fits well, then why bother changing it?

As for the issue of knees against bars, try leaning a bit backwards when standing on the pedals. That way you'll also generate a bit more power, despite it feeling a bit less comfortable than leaning further forward. I hope my feedback is of help.

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