Experimenting with guardless devettes, comparing Spitfire R41 cap to 2013 cap ground down to the same width, and experiencing the waxy face feel of the R41 and the G.B.S. bakelite razors has raised some questions for me:



1) How does the depth and convexity of the top cap of a DE affect the shave?

The Spitfire cap and a 2013 R41 cap ground down to the same 18.6mm width shave very differently although the guard bar is the same.

The Spitfire cap is shallower and less convex, but why does this make a difference to the end result even with steep angle (when it shouldn't come into play)?



2) With large blade gap razors, the guard bar seems to still be important but not to protect from the blade biting but rather to stretch the skin.

The guardless devette needs skin stretching to be smooth, but the R41 and some fierce bakelites are naturally smooth without this.



So how do the top cap and guard bar interact for the stretching effect?

And are toothcombs specifically designed to give the best skin stretching?



3) My two big toothcomb razors, the R41 and G.B.S. bakelite, both leave my skin feeling soft waxy and conditioned after the shave in a way that no other razors do.

It almost feels like the skin has been moisturised.

So what causes this effect?



I know some of you are deep into the mechanics and geometry of DE heads, so what do you think?