KBS 560 / 580 Junior Shaft Grip Sizing

[SNEAKBIRD]

My son just turned 10 and is completely addicted to golf; his Mom was an elite college player which has always fascinated him. He plays many sports and we have kept him away from golf as long as we can but the dam broke this summer and he could not be contained. Recently, his coach pointed out that he is overpowering his US Kids clubs which got my mind turning. Bottom line, I just bought him some cheap ebay Mizuno MP 54 heads and will have them built with either the KBS 560 or 580 junior shaft. My understanding is that both shafts perform identically with the only difference being their butt diameter. What I can't figure out is how to arrive at the correct size grip in both scenarios. My wife thinks he should go a size down from standard, which I assume is a "Undersize" or "Ladies" grip size. His hands measure just over 6". I'm leaning towards the .580 sized shaft because it seems that there are more grips available in that core size.

 

Please help me solve this:

1. Undersized Grip Size = .560 Shaft + "X-sized Grip" + X-wraps of Tape
   
2. Undersized Grip Size = .580 Shaft + "X-sized Grip" + X-wraps of Tape
   

 

Thanks everyone!

[Cwebb]

A .580 core "undersized" grip on a .580 shaft with one wrap of tape, will result in the actual size the manufacturer intended. Unless you're looking for the grip to play smaller, I'd go with this

[SNEAKBIRD]

Thanks! Shafts arrive soon!

 

A .580 core "undersized" grip on a .580 shaft with one wrap of tape, will result in the actual size the manufacturer intended. Unless you're looking for the grip to play smaller, I'd go with this