The pizza cutter strikes again
#1
Senior Member
Thread Starter
The pizza cutter strikes again
Hugo Hofstetter left with huge cut in ear after dramatic crash at Circuit de la Sarthe, questions safety of disc brakes.
https://www.velonews.com/news/road/f...th-disc-brake/
https://www.velonews.com/news/road/f...th-disc-brake/
#2
Senior Member
Join Date: Mar 2010
Location: Seattle, WA
Posts: 23,208
Mentioned: 89 Post(s)
Tagged: 0 Thread(s)
Quoted: 18883 Post(s)
Liked 10,646 Times
in
6,054 Posts
Brakes at all are dangerous, what we need are rocket boosters, fixies, and some PBR!
#3
Senior Member
Join Date: Oct 2013
Location: Mich
Posts: 7,389
Bikes: RSO E-tire dropper fixie brifter
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked 2,969 Times
in
1,918 Posts
keep a safe personal space distance from all crashes.
__________________
-Oh Hey!
-Oh Hey!
Likes For Troul:
#4
Senior Member
Join Date: Jan 2010
Location: TC, MN
Posts: 39,520
Bikes: R3 Disc, Haanjo
Mentioned: 354 Post(s)
Tagged: 1 Thread(s)
Quoted: 20810 Post(s)
Liked 9,456 Times
in
4,672 Posts
How does a rotor cause a small puncture like the one that's in line with the gash? I guess I can't tell if that's a ridge or a valley between the two.
Likes For phrantic09:
#6
working on my sandal tan
Join Date: Aug 2011
Location: CID
Posts: 22,629
Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers), All-City Space Horse (hers)
Mentioned: 98 Post(s)
Tagged: 0 Thread(s)
Quoted: 3871 Post(s)
Liked 2,568 Times
in
1,579 Posts
Dumb question... I don't have a lot of experience with discs, but how does a 2mm thick rotor become "razor-sharp"? I do have some experience with razors, and they are quite thin.
Wouldn't rounding the outer edge a bit keep it from getting sharp during a reasonable service life?
Wouldn't rounding the outer edge a bit keep it from getting sharp during a reasonable service life?
#7
Senior Member
Join Date: Oct 2013
Location: Mich
Posts: 7,389
Bikes: RSO E-tire dropper fixie brifter
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked 2,969 Times
in
1,918 Posts
Dumb question... I don't have a lot of experience with discs, but how does a 2mm thick rotor become "razor-sharp"? I do have some experience with razors, and they are quite thin.
Wouldn't rounding the outer edge a bit keep it from getting sharp during a reasonable service life?
Wouldn't rounding the outer edge a bit keep it from getting sharp during a reasonable service life?
__________________
-Oh Hey!
-Oh Hey!
#8
Senior Member
Join Date: Jan 2010
Location: TC, MN
Posts: 39,520
Bikes: R3 Disc, Haanjo
Mentioned: 354 Post(s)
Tagged: 1 Thread(s)
Quoted: 20810 Post(s)
Liked 9,456 Times
in
4,672 Posts
Dumb question... I don't have a lot of experience with discs, but how does a 2mm thick rotor become "razor-sharp"? I do have some experience with razors, and they are quite thin.
Wouldn't rounding the outer edge a bit keep it from getting sharp during a reasonable service life?
Wouldn't rounding the outer edge a bit keep it from getting sharp during a reasonable service life?
FWIW you *can* get an extremely sharp edge out a nominal 90° angle, but it takes some work teasing out and burnishing that edge (which is how woodworking cabinet/card scrapers work). The rounding off that the manufacturers do should prevent anything near that level of sharpness for the lifespan of the rotor.
#9
Disco Infiltrator
Join Date: May 2013
Location: Folsom CA
Posts: 13,446
Bikes: Stormchaser, Paramount, Tilt, Samba tandem
Mentioned: 72 Post(s)
Tagged: 0 Thread(s)
Quoted: 3126 Post(s)
Liked 2,105 Times
in
1,369 Posts
#10
-------
Join Date: Jul 2020
Location: Tejas
Posts: 12,795
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 9653 Post(s)
Liked 6,365 Times
in
3,505 Posts
Dumb question... I don't have a lot of experience with discs, but how does a 2mm thick rotor become "razor-sharp"? I do have some experience with razors, and they are quite thin.
Wouldn't rounding the outer edge a bit keep it from getting sharp during a reasonable service life?
Wouldn't rounding the outer edge a bit keep it from getting sharp during a reasonable service life?
Likes For Mojo31:
#11
Disco Infiltrator
Join Date: May 2013
Location: Folsom CA
Posts: 13,446
Bikes: Stormchaser, Paramount, Tilt, Samba tandem
Mentioned: 72 Post(s)
Tagged: 0 Thread(s)
Quoted: 3126 Post(s)
Liked 2,105 Times
in
1,369 Posts
Some questioned the propriety of some riders using fast-stopping discs while others were managing the different deceleration offered by rim brakes.
__________________
Genesis 49:16-17
Genesis 49:16-17
#12
Disco Infiltrator
Join Date: May 2013
Location: Folsom CA
Posts: 13,446
Bikes: Stormchaser, Paramount, Tilt, Samba tandem
Mentioned: 72 Post(s)
Tagged: 0 Thread(s)
Quoted: 3126 Post(s)
Liked 2,105 Times
in
1,369 Posts
Likes For Darth Lefty:
#13
-------
Join Date: Jul 2020
Location: Tejas
Posts: 12,795
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 9653 Post(s)
Liked 6,365 Times
in
3,505 Posts
Don't know. Put your bike on a stand and start spinning the rear wheel. Put your finger on the edge and see what happens. If no cut, increase the speed of the wheel and try again. Eventually, you'll find out what it takes.
Or, maybe he didn't get "cut." Maybe his ear got caught in something around the area of the disc and was torn in the melee. The article did not really say what specific injury he had. In lay usage, the word "cut" can mean a lot of different things.
Or, maybe he didn't get "cut." Maybe his ear got caught in something around the area of the disc and was torn in the melee. The article did not really say what specific injury he had. In lay usage, the word "cut" can mean a lot of different things.
Likes For Mojo31:
#14
Disco Infiltrator
Join Date: May 2013
Location: Folsom CA
Posts: 13,446
Bikes: Stormchaser, Paramount, Tilt, Samba tandem
Mentioned: 72 Post(s)
Tagged: 0 Thread(s)
Quoted: 3126 Post(s)
Liked 2,105 Times
in
1,369 Posts
Perhaps we need safety razor discs with 5 blades
__________________
Genesis 49:16-17
Genesis 49:16-17
#15
Senior Member
Join Date: Mar 2010
Location: Seattle, WA
Posts: 23,208
Mentioned: 89 Post(s)
Tagged: 0 Thread(s)
Quoted: 18883 Post(s)
Liked 10,646 Times
in
6,054 Posts
I think the OP's point is that racing is dangerous and Big Bike should stop forcing it on us.
#16
Senior Member
Join Date: Jul 2009
Posts: 5,949
Bikes: Colnago, Van Dessel, Factor, Cervelo, Ritchey
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 3951 Post(s)
Liked 7,296 Times
in
2,946 Posts
I don't think there's any way that a disc brake rotor could damage a helmet like that unless it was removed from the hub and thrown by a ninja.
#17
Senior Member
Join Date: Jan 2010
Location: TC, MN
Posts: 39,520
Bikes: R3 Disc, Haanjo
Mentioned: 354 Post(s)
Tagged: 1 Thread(s)
Quoted: 20810 Post(s)
Liked 9,456 Times
in
4,672 Posts
#18
Disco Infiltrator
Join Date: May 2013
Location: Folsom CA
Posts: 13,446
Bikes: Stormchaser, Paramount, Tilt, Samba tandem
Mentioned: 72 Post(s)
Tagged: 0 Thread(s)
Quoted: 3126 Post(s)
Liked 2,105 Times
in
1,369 Posts
__________________
Genesis 49:16-17
Genesis 49:16-17
#19
-------
Join Date: Jul 2020
Location: Tejas
Posts: 12,795
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 9653 Post(s)
Liked 6,365 Times
in
3,505 Posts
Damn, bruv, brave move!
Likes For Mojo31:
#20
• —
Join Date: Jun 2015
Location: Land of Pleasant Living
Posts: 12,233
Bikes: Shmikes
Mentioned: 59 Post(s)
Tagged: 0 Thread(s)
Quoted: 10167 Post(s)
Liked 5,860 Times
in
3,154 Posts
If the discs are good and hot, they’ll self-cauterize the wound, making extensive debridement necessary, but preventing potential exsanguination.
Likes For MoAlpha:
#21
Senior Member
Join Date: Sep 2005
Location: In the foothills of Los Angeles County
Posts: 25,288
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 8279 Post(s)
Liked 9,034 Times
in
4,472 Posts
I have a chainring scar on my left leg from falling off of my mtb. Let's get rid of those dangerous chainrings.
#22
-------
Join Date: Jul 2020
Location: Tejas
Posts: 12,795
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 9653 Post(s)
Liked 6,365 Times
in
3,505 Posts
Likes For Mojo31:
#23
Senior Member
Join Date: Mar 2010
Location: Seattle, WA
Posts: 23,208
Mentioned: 89 Post(s)
Tagged: 0 Thread(s)
Quoted: 18883 Post(s)
Liked 10,646 Times
in
6,054 Posts
You guys should see my legs after an hour with kittens!
Likes For Seattle Forrest:
#24
Banned.
It's one reason I went 1x. No more exposed teeth from the chainring because the chain shrouds them at all times and 1x chainring tend to have more dull/wider teeth, less likely to cut even if exposed.
Likes For qwaalodge:
#25
Senior Member
The real danger is hitting the tarmac at 30 mph in a virtual bathing suit and an eggshell. - Happens in almost every pro road race. Blaming the brake discs is a red herring.
Likes For Racing Dan: