Any tricks to 'sizing" a helmet?

[FLrider]

I just bought a new Shoei RF1100. My last helmet (Shoe TRZ) fit comfortably when I bought it, but after 2 years of use, the fit has gotten a little sloppy.

 

So, when I bought the new helmet, I went down a size figuring that as I wore it, it would break in, and fit just right.

 

Problem is, it's tolerably tight but after about 15 minutes or so, I can feel myself bringing on a headache.

 

My dad used to have this gizmo that he would insert into his shoes and with a few turns of a knob, the insert would expand, stretching the leather.

 

Any of you guys have any tips that might "speed up" the break in process?

 

I am confident that I have the right size. The next size up just moves around too much.

[Danny caddyshack Noonan]

Assuming that the helmet is the correct size to begin with, a large spoon can deform small areas of the EPS foam. However, with each deformation, you gain comfort but lose a bit of safety margin. Some heads won't find a helmet to fit and have to do this.

With Shoei, you can usually get new cheek pads. I bought two extra sets.