I was given a Xtreme Productions delrin main gear for the Solo Pro. So I took the weight differences between the v911, Solo Pro and Xtreme.
The v911 is the lightest, and very slightly thinner than the other two.
Here’s the weight of the stock v911 main shaft compared to the Solo Pro’s carbon fiber main shaft. In case you’re wondering, the Solo Pro main shaft is a drop in fit. No mods needed.