OK. I've been reading the forums at TSD for about a month now and regularly see references to aggressive and mild razors. I'm using a Tech and a Super Speed, both of which I have read are mild shavers. They both do a great job and I can't see how I could have a more aggressive shave. Can somebody explain the difference between and aggressive and mild razor?
There are a few geometries that contribute to a razor's aggressiveness. First, and probably most importantly, is the distance between the blade edge and the bottom plate guard. A larger gap allows for more or thicker hair to enter between the razor edge and the safety bar to be cut. The second geometry is blade exposure. Imagine drawing a line that touches the very edge of the top plate and the safety bar on the bottom plate. How much the razor blade edge sticks out past this line is the measurement referred to as blade exposure. For obvious reasons, a razor with a large blade exposure is a more effective cutter, if more irritating, as it allows for more of the applied force to be transferred from the blade to the hair (as opposed to the force being transferred from the top plate or bottom plate to the face). The third dimension is cutting angle. While the angle you hold the razor at is determined by the imaginary line discussed earlier, the angle between the face and the blade edge when the razor itself is held at the proper angle to the face is the cutting angle. The shallower the cutting angle, the more aggressive the razor. Imagine shaving with a straight razor. If you hold it perpendicular to your skin, you're not going to cut whiskers. You'll just rub your skin off. If you hold it almost parallel to your face, it'll cut all your whiskers off, as well as most of your face. The shallower the angle, the greater the cutting power of the blade. An aggressive razor, such as the futur, combines all three of these to whack at some big nasty whiskers. The futur set to 6 has a blade gap of something like 1.5mm and a blade exposure of about .3mm, with a cutting angle of about 8 degrees. By comparison, a superspeed has a blade gap of maybe .5mm, a blade exposure of 0mm, and a cutting angle of about 25 degrees. (the latter are educated guesses, as I no longer own a superspeed, and am just looking at a picture). If you have fine whiskers, a mild razor is the ticket. If you have a steel wool foundry on your face like me, a Futur on 6 or a GEM Micromatic Open Comb is the weapon of choice.
This is a scheme I made for Russian shaving blog. It should help to understand geometry in addition to what aberneth said Blade exposure - the distance between the edge of the blade and the tangent to the razor head. In essence - this is the distance that the blade is drawn to the surface of the skin and from which your face is not protected by a razor (if applied flat, of course); Gap - the distance between the guard and support blade; Span - the distance between the edge of the blade and the edge of the guard guard; Guard - the bottom portion of the razor head also protects the face from the blade. alpha angle - is that famous 30 degree recommended angle.
Ooops... It was a combination of a great diagram (on topic) and making me hungry (off topic). Nice granite!!
Perfect. Thank you for the great explanation. Now that I've read your explanation and seen Alexy's diagram, it makes sense. My wiskers are thick but fine (if that makes sense) so the Tech and SuperSpeed works perfectly for me.
Well then .. and this' easy! razor aggressive can 'Strip off the face, taking away the skin flap, and a razor makes you feel comfortable in paradise without the need to be dead! ahahahahaha joking of course .... :happy102
Fantastic diagram! I thought about making a crude diagram, but it was some time past midnight and I wanted to be in bed I'm curious if you would distinguish between the angle at which you hold the razor and the angle at which the blade intersects the face. Essentially, the flatter the blade between the plates, the less aggressive the razor. I know that with a razor like a futur, the blade is quite curved. Am I right in this, or is my line of thought convoluted?
Yes, this is cutting angle. It changes from razor to razor. As I remember from the straight methodology, it is recommended to cut at 30 degrees for WTG pass, at 15 degrees at XTG pass and at 5 degrees at ATG pass.
That's not quite what I meant. I'll draw up a diagram when I get home for the day. I'm not so good with these "word" things
Cutting angle is formed from the angle at which blade sits in razor relative to the tangle to razor head and the angle at which you hold the razor. It's simple
Okay, yeah, that's it. However, I thought that this angle was a constant, as the angle made between the razor's long axis and your face is pre-determined by the geometry of the top and bottom plate, and barring an adjustable, the angle between the razor blade and the guard is constant.
Adjustables are something different in this concept. Most of them simply bend the blade, thus change the angle at which blade sits. More angle = more exposure. Some Gillette Toggles changed the gap Too much math... It's almost midnight here. I gotta resist further thoughts
