I thought stock was size 20.5X17 and weight 10.3.

I can buy either 10.25 or 11. ( Don't know the units, I assume they are grams.)

I'm adding a Scorpion Pipe and don't know what to get.

As top speed hiway riding is more important to me than taking off fast, (only because the pick up is fine the way it is) I would think the 10.25 is the way to go.

Any comments form anyone with experiance would be appricialted.