Try 8 to 10mm of prebend without the mast up, with the rig on and sailing this should come out to about zero prebend with a very tight dolphin striker strap.

My Dolphin striker post is 25mm OD, 3mm wall thickness. Goes through the beam and attaches to underside of mast step. Your not compressing the front beam between the post and the mast step are you?

What club do you sail at Nick? I would like to follow the results of your new platform.

Darryn
Mozzy
1782