high revs and tough shifting

[aphex301]

Whenever i pull hard in first gear and over 5500rmps or so, while shifting into second i sometimes get a grind if i dont shift hard enough. I have to shift hard and fast in order not to get the grind. Does anyone know why shifting into second is so hard and i get a grind. Keep in mind that while not racing or driving agressively, everything is fine and it shifts like a dream.
would synchonizers be the culprit here, or is it something more?
thanks.

 

[1LE]

You're making the tranny do something it doesn't want to. It beats on the synchros, and if they're not in perfect shape, it grinds.