I'm sure I posted this in another thread the other day... I'd argue any razor with a negative blade exposure is a slightly flawed design. As you suggest, these razors may work poorly with a less wide blade. Some razors work well with any blade as they have positive blade exposure with all blades. I'd stick to those razors. BUT some people claim the Mamba gives them a BBS shave with Polsilver. Others feather blades. Some derby. If it's negative blade exposure means the blade doesn't get as close, how is this possible? I think the actual answer is that all of the minute differences actually make very little difference. A blades a blade.
Kai is an outlier in terms of blade width , every other blade seems to measure the same or close enough. Razors with negative exposure may require some pressure to maintain optimum contact that's all. It's certainly possible to get a BBS shave with negative exposure given proper technique with any blade.
I would agree that blade exposure isn't such an issue for the gamechanger but I'm not convinced that's because of blade exposure, more something else to do with the geometry beyond my understanding. Some blades definitely have neutral or negative exposure, e.g. Treet / Personnas: However, unlike the Mamba it doesn't seem to affect the shave so significantly. But I would argue that the blade exposure is more noticeable as a result over a razor which has a lot of exposure with any blade.
No idea what you are talking about here, blade exposure is a function of head design, not the blade. Blades are a standard width (+/- .08mm, ie .04mm per side in exposure), Kai exception previously noted.
The Gamechanger seems to perform ok with any blade, but I personally notice a big difference with the Kai. The Mamba is the only razor I have had difficulty with, ever, and my RAD issues have led me to try a fair few. But the Mamba was transformed with a blade change, and has gone from being my least favourite to one of my favourites.
Treet Dura Sharp carbon and American Personnas are noticeably narrower. The Personnas are a fantastic blade for more aggressive razors.
I presume you "notice" using a micrometer or calipers rather than your eyeballs to discern differences of less than .1mm, can you share measurements? By my callipers the Platinum Treet measures in the normal range (21.9ish), don't have the carbon or Personna Blue on hand.
I'm sure most of the experiences here are based on the M.53 , what I'm showing here is the M.70 with a Gillette Super Thin Platinum (Thai), will append thread later once I've shaved with my thoughts on how the M70 compares to the GC.84 with a proven favorite blade for me.
Well, just stowed the gear, as expected the M.70 is milder than the GC.84. I pulled a BBS shave with two passes save for top of neck, which I normally do cross grain up and down with the GC. With the Mamba I did it WTG then cross grain up and went back ATG. My suspicion is if I do the area WTG/ATG it yields BBS in two passes like the GC. I liken the shave of the M.70 to my Pils, with a distinct handling advantage to the M.70, the Pils is head heavy, handle centric and the head has a large profile with makes the under the nostril area a bit of work, let alone the price difference. The M.7o is a great 'mild razor'. In time I'll find out if it's blade selective but I still give the nod to the GC.84 as my go to stick.
Some further food for thoughts as I continue my blade testing with the M.70. Starting with my fav, a two pass blade in all my sticks, and work to nick oneself with. The M.70 was two passes in most places with a third. From there went to a mid-performing blade, good shave but tad more nick prone than my favs, to test my theory a milder head can tame blades. This turned into a three pass exercise, nick free, but did require pressure I don't have to use with the GC.84 and others. From there put my money where my mouth is, and grabbed what I've found to be an unforgiving blade that razor burns me at best and has nicked me in even my mild heads, the feather. The only one I've found meaner has been the Kai DE. To my surprise the M.70 work the feather almost nick-free, two pass, zero razor burn. Additionally, the feather didn't require the pressure that the personna on the second pass. With these revelations I still feel there's something to be said for head/blade optimization for one's beard/skin type. For me it's now more, where's a head like this' place in my arsenal? Do I keep it in rotation with my other mild heads? Save it for days when I want to use aggressive blades? Seems pretty limited/low frequency of use.
The carbon is a lot narrower. Around the 21.63 mark. But my caliper measurements seem slightly different to yours I make Kais slightly wider. You probably have a better measurement technque than me. Regarding the Mamba, this from the Italian Barber web site: "Blade Exposure: ~0 to -0.01mm (I say roughly because of blade width variances)" The thing is we don't know what blade width the Mamba is aimed at. If it's Derby Extra, even the Astras would have a negative blade exposure at the tolerances Razorock have gone for.
I felt the same when I first got the Mamba working for me. Then after some reflection I changed my mind. It's a high precision razor, not a flexible shaving tool, but that's all right for me - it requires precise blade matching and technique and as a result it produces very precise results. When I first used the Mamba it was the worst DE shave I have had in 30 years of DE shaving. Now I have invested time in it I might go as far to say it gives the best DE shaves.
While I understand your point it's not self evident that differences of this magnitude (less than .05mm per side) would be noticeable. I use the "narrow" BIC often and certainly notice no difference in exposure. One never hears the BIC described as mild due to lack of exposure. I don't recall anyone even mentioning the Kai until after its width was measured (and thus opinions subject to confirmation bias). Marvelous Mamba/Bic combo today.
