Why the curve?

[jamesspo]

Thanks everyone... I think what I meant about the perfectly close was misinterpreted... by perfectly close I mean the following... please correct me if I am misinformed.... (Also please disregard my terrible excuse of a drawing!

The use of the curved cap makes sense to allow you to get into tight spaces e.g. the upper lip/under nose area but to me it seems that if you hold the razor either too steep or too shallow it cuts hair, but away from the skin preventing a perfectly close shave no?

You're describing a particular case of a razor that has zero blade exposure (e.g. no protrusion of the blade past a line tangent to the cap and guard). You're correct, for that situation you only effectively have one angle that "works". In practice however you do get a little wider range than that, as your skin is flexible, and can be squeezed into the gaps, allowing cutting to occur outside the design angle. So indeed, if the cap and guard were extended along the skin line a bit to form a flat plane, it probably would assist in getting the angle right, and would prevent any use outside of that angle. It basically would turn the DE into a cartridge-like razor . Myself, I prefer the flexibility of the curved design, and more so, a razor with more blade exposure so you can set your own blade angle.

 

[jamesspo]

Oh really? How much are we talking?... anyone know a specific figure... something like the 34c?

Thanks.

Many razors have non-zero blade exposure. It's tougher to find one that doesn't than one that does. It's not a huge amount - on the order of .5mm or less in most cases. The R41 may be more than that. It's a little tough to measure. There is a great thread available where one of our members took some photos of a few vintage Gillette's showing their blade exposure. Let me go find a link to that...


Here we go. I think will help you get a picture of what's typical:

http://badgerandblade.com/vb/showthread.php/162987-Photo-Analysis-of-Razor-Designs

 

[kingfisher]

Gives the blade the cutting angle. If you look inside, you'll see that the razor actually bends the blade at the center point to give a user friendly cutting angle. If there was no bend, it would be very awkward to shave with.

Not true at all.

The Tradere SB is one of my favorite DE razors, and it doesn't bend the blade.

The main reason for the bend is to provide stiffness; the Tradere holds the blade so rigidly in the straight position that stiffness is achieved without bending the blade. The shave is, if anything, even more intuitive than most DE razors, and not difficult at all.

 

[jb91]

Many razors have non-zero blade exposure. It's tougher to find one that doesn't than one that does. It's not a huge amount - on the order of .5mm or less in most cases. The R41 may be more than that. It's a little tough to measure. There is a great thread available where one of our members took some photos of a few vintage Gillette's showing their blade exposure. Let me go find a link to that...


Here we go. I think will help you get a picture of what's typical:

http://badgerandblade.com/vb/showthread.php/162987-Photo-Analysis-of-Razor-Designs

That is really interesting, thank you! I just assumed they would all be zero blade exposures so you didn't cut yourself but that makes sense.

That article goes on to say how the more the blade is exposed, the less pressure you would use on the skin to prevent razor burn, I am guessing that if you have a zero blade exposure the gap between the blade and guard should be just a tad bigger to allow the skin to squeeze into that gap and allow a perfectly smooth shave.

Thanks so much for everyones input.

Kingfisher: Does the Tradere SB still cut at around 30 degrees?

 

[kingfisher]

I believe so, yes; the 30 degrees being the angle between the blade itself and the skin. The angle at which the handle is held varies a lot from razor to razor, especially comparing, for example, the Tradere to a razor that really bends the blade a lot, like a Progress.

 

[embalyst]

If you are asking about the curved surface shape of the head, it is the result of designing a multi-purpose tool that interfaces with concave, convex and flat surfaces in two directions.

Yeah....what he said....

 

[jwray15]

Try this simple experiment with a thin piece of any material that has some stiffness. Bend it. Now try bending it in the right angle direction at the same time. You can't. The same principle applies to razor blades. Bending the blade crosswise makes the edge more rigid.

^^ this