Shave'n Blind Blade Test
- Thread starter alexface
- Start Date
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- Cumbria, England
For me the Astra SP were my favourites, closely followed by Astra SS. The Gillette 7 O' Clocks were pretty good, as was the Shark which was a new one to me.
I absolutely hated the Wilkinson Sword which felt like it hadn't been sharpened at the factory, and a Russian thing (Rapira?) that felt about the same. A special dishonourable mention goes to Feather, the first gave me two good shaves and then turned into a hacksaw and the second was crap out of the packet.
None of the blades were better than a Personna med, however the Astra SP have cemented their position as an excellent second choice blade. I was happy to see that my blind ratings matched my previous experience with the blades I'd tried before.
I absolutely hated the Wilkinson Sword which felt like it hadn't been sharpened at the factory, and a Russian thing (Rapira?) that felt about the same. A special dishonourable mention goes to Feather, the first gave me two good shaves and then turned into a hacksaw and the second was crap out of the packet.
None of the blades were better than a Personna med, however the Astra SP have cemented their position as an excellent second choice blade. I was happy to see that my blind ratings matched my previous experience with the blades I'd tried before.
OP
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- 81
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- North of the Pole
- Thread Starter
- #83
Hi Gentlemen, I've been busy with family and this thing called 'life'. I'll be under a rock for at least another month or two.
I'm happy to read your blade experiences and reactions. Feel free to continue discussing round one, but please refrain from discussing round two at this time.
FYI, I sent out 31 blade packs. 4 guys dropped out or simply vanished without contacting me. 7 have begun but not completed round one. 10 round one packs have been completed. 4 have begun but not completed round two. 6 guys have not started round two.
Round one (aka trial round) was a practical learning experience for me. There are multiple organization concepts represented in round one. All packs have some duplication; In many packs there are exactly two of each blade brand. Most blades are compared against four different blades (consider ABCDEACEBD). The wider test consists of 20 different blades; Obviously each participant only received a subset of the total possible blade brands. However, there are 10 core blade brands such as Feather and Astra SP meant to string the wider results together.
Round two consolidates the blade brands. Participants generally received the same blades with similar order patterns but in entirely different sequences. The blade brands were selected based on round one core blades, participant preferences, supply, and whim.
I expected all round one participants to have completed by now; Unfortunately, that's not the case. I hope to compile some early statistics to whet your appetites, but don't hold your breath waiting.
I'm happy to read your blade experiences and reactions. Feel free to continue discussing round one, but please refrain from discussing round two at this time.
FYI, I sent out 31 blade packs. 4 guys dropped out or simply vanished without contacting me. 7 have begun but not completed round one. 10 round one packs have been completed. 4 have begun but not completed round two. 6 guys have not started round two.
Round one (aka trial round) was a practical learning experience for me. There are multiple organization concepts represented in round one. All packs have some duplication; In many packs there are exactly two of each blade brand. Most blades are compared against four different blades (consider ABCDEACEBD). The wider test consists of 20 different blades; Obviously each participant only received a subset of the total possible blade brands. However, there are 10 core blade brands such as Feather and Astra SP meant to string the wider results together.
Round two consolidates the blade brands. Participants generally received the same blades with similar order patterns but in entirely different sequences. The blade brands were selected based on round one core blades, participant preferences, supply, and whim.
I expected all round one participants to have completed by now; Unfortunately, that's not the case. I hope to compile some early statistics to whet your appetites, but don't hold your breath waiting.
OP
- Messages
- 81
- Location
- North of the Pole
- Thread Starter
- #84
Some very preliminary findings with respect to three blades...
Astra SP were perceived as sharper, more comfortable, and preferred over Shark Super Stainless.
Astra SP were perceived as more comfortable and preferred over Feather. There were also significant number of participants who perceived Astra SP and Feather similar with respect to comfort and preference. Neither was perceived to be significantly more sharp than the other.
Edited 27 May, 2015. Findings that were no longer supported by new data have been eliminated. No new findings added to this post.
Astra SP were perceived as sharper, more comfortable, and preferred over Shark Super Stainless.
Astra SP were perceived as more comfortable and preferred over Feather. There were also significant number of participants who perceived Astra SP and Feather similar with respect to comfort and preference. Neither was perceived to be significantly more sharp than the other.
Edited 27 May, 2015. Findings that were no longer supported by new data have been eliminated. No new findings added to this post.
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Your third finding is surprising, with the "reputation" of feather being super sharp at all costs.
Joel
Joel
OP
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- #86
Before much more data comes in, these are just prelim tentative findings. The error bars (themselves shaky calculations) are enormous. The findings I posted were only >2% shy of random. From the above we might also assume that Feathers are sharper than Sharks, but I just don't have the data to assert that (I've found transitivity unreliable). However, the data do show that Feathers' reputation for sharpness is contestable.
alexface said:
This is why I so love science. If blind-study data can reliably conclude that Astra is even just about as sharp as Feather ... that alone would be a huge step forward in consumer understanding of DE blades....
One guy's free-time project (plus all of the study's participants) can suddenly call into question the previously accepted wisdom of hundreds (if not thousands) of posts across dozens of websites.
So much of consumer DE shaving knowledge has been based on anecdotal evidence and influenced by reputation-bias (if that's a term?). I am very happy to see us as a shaving community starting to improve upon this.
Awesome work, Alex.
By the way ... before I get too excited ... what's your sample size on this data?
Cheers,
Shawn
OP
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- North of the Pole
- Thread Starter
- #89
12 to 24 data points for the above findings. Error roughly 20% < 1/sqrt
< 29%.
< 29%.
OP
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- 81
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- North of the Pole
- Thread Starter
- #91
The three shave results are merged.
The group that found the two blades equally sharp was a large percent and the difference between the sharper and duller groups falls within sampling error. Feather seems to be sharper on the first shave and dull progressively thereafter, but again, the differences are well within error.
The group that found the two blades equally sharp was a large percent and the difference between the sharper and duller groups falls within sampling error. Feather seems to be sharper on the first shave and dull progressively thereafter, but again, the differences are well within error.
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alexface said:
Which is why no-one attempts a third shave with a Feather and gives you your skewed result.
- Messages
- 3,477
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- Cumbria, England
I've never felt that Feathers were noticeably sharper than Astras even on their first shave.
OP
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- 81
- Location
- North of the Pole
- Thread Starter
- #94
Gillette 7OC Super Stainless (Green) were perceived to be sharper than Rapira Platinum Lux.
Gillette 7OC SharpEdge (Yellow) were perceived to be sharper than Feathers.
Greens and Yellows were rated similarly sharp.
Feathers were rated sharper than Derby.
Astra SP were rated sharper than Shark Super Stainless and Gillette 7OC Super Platinum (Black, India).
Feathers, Astra SP, Derby, and Shark SS were all rated sharper than Personna Lab Blues.
Astra SP were perceived to be more comfortable than Feather, Shark SS, and Derby.
Feather and Shark SS were also perceived to be more comfortable than Derby.
Greens were preferred over Rapira Platinum Lux.
Astra SP were preferred over Feather, Shark SS and Derby.
Feather were preferred over Derby.
Shark SS were preferred over Personna Labs.
Edited 27 May. Orange findings are no longer strongly supported by new data. No new findings have been added to this post.
Gillette 7OC SharpEdge (Yellow) were perceived to be sharper than Feathers.
Greens and Yellows were rated similarly sharp.
Feathers were rated sharper than Derby.
Astra SP were rated sharper than Shark Super Stainless and Gillette 7OC Super Platinum (Black, India).
Feathers, Astra SP, Derby, and Shark SS were all rated sharper than Personna Lab Blues.
Astra SP were perceived to be more comfortable than Feather, Shark SS, and Derby.
Feather and Shark SS were also perceived to be more comfortable than Derby.
Greens were preferred over Rapira Platinum Lux.
Astra SP were preferred over Feather, Shark SS and Derby.
Feather were preferred over Derby.
Shark SS were preferred over Personna Labs.
Edited 27 May. Orange findings are no longer strongly supported by new data. No new findings have been added to this post.
OP
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- 81
- Location
- North of the Pole
- Thread Starter
- #95
There is a strong correlation (84%) between blade comfort and preference, a moderate correlation (74%) between sharpness and preference, a mild correlation (68%) between sharpness and comfort, and a mild correlation (64%) between all three.
When two blades are similarly sharp, the more comfortable blade is preferred 80% of the time and never disliked. When two blades are similarly comfortable, the sharper blade is preferred 56% and disliked 6% of the time. When two blades are similarly sharp and similarly comfortable, one is preferred 11% of the time (I wish I knew why!).
Of blades perceived to be more comfortable, 90% are preferred and 3% disliked, irrespective of perceived sharpness. Of blades perceived to be sharper, 79% are preferred and 11% disliked, irrespective of perceived comfort.
In other words, guys greatly prefer a comfy blade, which is often also the sharper blade.
48.7% (sharper comfort preferred)
15.4% (similar similar similar)
9.3% (similar comfort preferred)
6.8% (sharper harsher disliked)
6.1% (sharper similar preferred)
4.2% (sharper similar similar)
2.3% (similar comfort similar)
1.9% (sharper harsher similar)
1.9% (similar similar preferred)
1.3% (sharper harsher preferred)
0.8% (sharper comfort similar)
0.6% (sharper comfort disliked)
0.6% (sharper similar disliked)
0.0% (similar comfort disliked)
===
100.0% (rounded above, +/-4.6% sampling error)
* Note that for example (A is sharper harsher preferred over B) implies/same as (B is duller comfort disliked over A)
When two blades are similarly sharp, the more comfortable blade is preferred 80% of the time and never disliked. When two blades are similarly comfortable, the sharper blade is preferred 56% and disliked 6% of the time. When two blades are similarly sharp and similarly comfortable, one is preferred 11% of the time (I wish I knew why!).
Of blades perceived to be more comfortable, 90% are preferred and 3% disliked, irrespective of perceived sharpness. Of blades perceived to be sharper, 79% are preferred and 11% disliked, irrespective of perceived comfort.
In other words, guys greatly prefer a comfy blade, which is often also the sharper blade.
48.7% (sharper comfort preferred)
15.4% (similar similar similar)
9.3% (similar comfort preferred)
6.8% (sharper harsher disliked)
6.1% (sharper similar preferred)
4.2% (sharper similar similar)
2.3% (similar comfort similar)
1.9% (sharper harsher similar)
1.9% (similar similar preferred)
1.3% (sharper harsher preferred)
0.8% (sharper comfort similar)
0.6% (sharper comfort disliked)
0.6% (sharper similar disliked)
0.0% (similar comfort disliked)
===
100.0% (rounded above, +/-4.6% sampling error)
* Note that for example (A is sharper harsher preferred over B) implies/same as (B is duller comfort disliked over A)
OP
- Messages
- 81
- Location
- North of the Pole
- Thread Starter
- #96
New findings as of 27 May (green findings below considered stronger; previous posts have been edited with weaker findings).
Astra SP are perceived sharper than Shark SS.
Astra SP, Feather, Shark SS, and G7OC Super Platinum (Black, India) are perceived sharper than Personna Labs.
Feather and Astra SP are perceived to be sharper than Derby.
Astra SP are perceived to be sharper or similar to G7OC SharpEdge (Yellow).
Yellows and Feather are indistinguishable with respect to sharpness (not exactly similar as many perceive one sharper than the other).
Greens are perceived sharper than Rapira Lux Platinum.
Astra SP are perceived to be more comfortable than Shark SS, Derby, and Feather.
Gillette Silver Blue are perceived to be more comfortable than G7OC SharpEdge (Yellow).
Blacks are perceived more comfortable than Labs.
Gillette Silver Blue are perceived more comfortable than Yellows.
Greens are perceived more comfortable or similar to Rapira Lux Platinum.
Astra SP are preferred over Derby and Shark SS.
Shark SS are preferred over Personna Labs.
Astra SP and Blacks are preferred over Labs.
Feather and Gillette Silver Blue are preferred over Derby.
Greens are preferred over Rapira Lux.
Astra SP are perceived sharper than Shark SS.
Astra SP, Feather, Shark SS, and G7OC Super Platinum (Black, India) are perceived sharper than Personna Labs.
Feather and Astra SP are perceived to be sharper than Derby.
Astra SP are perceived to be sharper or similar to G7OC SharpEdge (Yellow).
Yellows and Feather are indistinguishable with respect to sharpness (not exactly similar as many perceive one sharper than the other).
Greens are perceived sharper than Rapira Lux Platinum.
Astra SP are perceived to be more comfortable than Shark SS, Derby, and Feather.
Gillette Silver Blue are perceived to be more comfortable than G7OC SharpEdge (Yellow).
Blacks are perceived more comfortable than Labs.
Gillette Silver Blue are perceived more comfortable than Yellows.
Greens are perceived more comfortable or similar to Rapira Lux Platinum.
Astra SP are preferred over Derby and Shark SS.
Shark SS are preferred over Personna Labs.
Astra SP and Blacks are preferred over Labs.
Feather and Gillette Silver Blue are preferred over Derby.
Greens are preferred over Rapira Lux.