Go Back  Bike Forums > Bike Forums > Road Cycling
Reload this Page >

The pizza cutter strikes again

Notices
Road Cycling “It is by riding a bicycle that you learn the contours of a country best, since you have to sweat up the hills and coast down them. Thus you remember them as they actually are, while in a motor car only a high hill impresses you, and you have no such accurate remembrance of country you have driven through as you gain by riding a bicycle.” -- Ernest Hemingway

The pizza cutter strikes again

Old 04-13-22, 10:11 PM
  #26  
Joearch
Junior Member
 
Join Date: Jun 2020
Location: Los Angeles
Posts: 142

Bikes: Bianchi Infinito CV Disc Ultegra

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 45 Post(s)
Liked 53 Times in 28 Posts
I must say that while pedaling along I have looked down at the front wheel, thinking to myself that the brake rotor does remind me of a dremmel cutting tool. Thought a number of times if I were to come in contact with someone with my rotor tne results would not be good. True there are a number of dangerous parts on the bike, the rotor is extra scary.
Joearch is offline  
Old 04-13-22, 10:26 PM
  #27  
Seattle Forrest
Senior Member
 
Seattle Forrest's Avatar
 
Join Date: Mar 2010
Location: Seattle, WA
Posts: 23,208
Mentioned: 86 Post(s)
Tagged: 0 Thread(s)
Quoted: 18879 Post(s)
Liked 10,638 Times in 6,049 Posts


I didn't realize how dangerous wheels with spokes are, I'm going full disc to play it safe. Having trouble finding a front one, might have to go with a faring.
Seattle Forrest is offline  
Likes For Seattle Forrest:
Old 04-14-22, 05:52 AM
  #28  
eduskator
Senior Member
 
eduskator's Avatar
 
Join Date: Aug 2019
Location: Québec, Canada
Posts: 1,365

Bikes: TCR Pro, Revolt Adv

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 583 Post(s)
Liked 333 Times in 256 Posts
''Questions safety of disc brakes''
I think there are a lot more people crashing because they lost their braking power due rim brake failures or inefficiency than people getting their ears cut by discs during a crash.
eduskator is offline  
Likes For eduskator:
Old 04-14-22, 07:30 AM
  #29  
qwaalodge
Banned.
 
Join Date: Jan 2022
Location: Kingdom of Qwaa
Posts: 307
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 211 Post(s)
Liked 78 Times in 61 Posts
Originally Posted by eduskator View Post
''Questions safety of disc brakes''
I think there are a lot more people crashing because they lost their braking power due rim brake failures or inefficiency than people getting their ears cut by discs during a crash.
True, the injury potential for losing brakes is far higher than getting into contact with hot, spinning disc rotors.

The biggest hazard of rim brakes is the tire or rim or both exploding during long descents in the warmer seasons. Apparently, the current solution to that problem (other than upgrading to disc brake) is minimize braking during long descents. A practice that can be quite problematic for many reasons especially when riding public roads
qwaalodge is offline  
Old 04-14-22, 07:39 AM
  #30  
MoAlpha
• —
 
Join Date: Jun 2015
Location: Land of Pleasant Living
Posts: 10,682

Bikes: Shmikes

Mentioned: 56 Post(s)
Tagged: 0 Thread(s)
Quoted: 8826 Post(s)
Liked 4,764 Times in 2,540 Posts
Originally Posted by big john View Post
I have a chainring scar on my left leg from falling off of my mtb. Let's get rid of those dangerous chainrings.
One of the more memorable cycling injuries I've seen was what a chainring did to someone's calf in a Wednesday night crit crash.
MoAlpha is offline  
Old 04-14-22, 08:31 AM
  #31  
big john
Senior Member
 
big john's Avatar
 
Join Date: Sep 2005
Location: In the foothills of Los Angeles County
Posts: 21,364
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 5746 Post(s)
Liked 5,500 Times in 2,819 Posts
Originally Posted by MoAlpha View Post
One of the more memorable cycling injuries I've seen was what a chainring did to someone's calf in a Wednesday night crit crash.
Mine isn't too bad. I can hardly see it anymore since I now have that old man skin. I have a worse one on my right leg from slipping off the kickstarter on my motorcycle when I tried to start it in work shoes.
big john is offline  
Likes For big john:
Old 04-14-22, 10:17 AM
  #32  
popeye
Senior Member
Thread Starter
 
Join Date: Nov 2004
Location: Newport Beach, CA
Posts: 1,916

Bikes: S works Tarmac, Felt TK2 track

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 354 Post(s)
Liked 164 Times in 103 Posts
Originally Posted by MoAlpha View Post
If the discs are good and hot, they’ll self-cauterize the wound, making extensive debridement necessary, but preventing potential exsanguination.
Says Gavin Mannion who was also injured this week:

“Both crashes were pretty minor except the fact that I landed on a hot rotor,” Mannion told CyclingTips. “For one, I needed eight stitches in the front of my knee, and for the other, I needed 12 staples in my hip. The cuts were so clean it was almost like the rotor burned through it.”
popeye is offline  
Likes For popeye:
Old 04-14-22, 10:34 AM
  #33  
bampilot06
Senior Member
 
Join Date: Dec 2019
Location: 757
Posts: 7,325

Bikes: Madone, Emonda, 5500, Ritchey Breakaway

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 6605 Post(s)
Liked 3,088 Times in 1,315 Posts
Bikes should have both rim and disc brakes at the same time. Ultimate stopping power plus redundancy. What could go wrong.
bampilot06 is offline  
Old 04-14-22, 10:38 AM
  #34  
himespau 
Senior Member
 
himespau's Avatar
 
Join Date: Jun 2008
Location: Louisville, KY
Posts: 13,148
Mentioned: 32 Post(s)
Tagged: 0 Thread(s)
Quoted: 3666 Post(s)
Liked 2,465 Times in 1,466 Posts
Originally Posted by big john View Post
I have a chainring scar on my left leg from falling off of my mtb. Let's get rid of those dangerous chainrings.
Outlaw platform pedals with pins or rat trap pedals. No way to know how many shins and calves have been carved up by those suckers over the years.
himespau is offline  
Likes For himespau:
Old 04-14-22, 11:30 AM
  #35  
eduskator
Senior Member
 
eduskator's Avatar
 
Join Date: Aug 2019
Location: Québec, Canada
Posts: 1,365

Bikes: TCR Pro, Revolt Adv

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 583 Post(s)
Liked 333 Times in 256 Posts
Originally Posted by qwaalodge View Post
True, the injury potential for losing brakes is far higher than getting into contact with hot, spinning disc rotors.

The biggest hazard of rim brakes is the tire or rim or both exploding during long descents in the warmer seasons. Apparently, the current solution to that problem (other than upgrading to disc brake) is minimize braking during long descents. A practice that can be quite problematic for many reasons especially when riding public roads
It does make sense! Never thought of that to be honest, but rubbing brake pads on a wheel for an extended period of time must heat the whole thing pretty seriously.
Hot air = increase in pressure = assploding tires!
eduskator is offline  
Old 04-14-22, 12:32 PM
  #36  
tomato coupe
Senior Member
 
Join Date: Jul 2009
Posts: 4,196

Bikes: Colnago, Van Dessel, Factor, Cervelo, Ritchey

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 2724 Post(s)
Liked 4,795 Times in 1,922 Posts
Originally Posted by MoAlpha
One of the more memorable cycling injuries I've seen was what a chainring did to someone's calf in a Wednesday night crit crash.


!!!WARNING!!!! Not for the squeamish, but a chain ring incident suffered by someone I used to ride with:

======> DO NOT CLICK ON THIS LINK IF SERIOUS WOUNDS UPSET YOU <=======


Did you read the above warning??

https://4.bp.blogspot.com/-H45qNo6GC...0/IMG_2742.JPG

Last edited by tomato coupe; 04-14-22 at 01:04 PM.
tomato coupe is offline  
Old 04-14-22, 12:45 PM
  #37  
Mojo31
-------
 
Join Date: Jul 2020
Location: Tejas
Posts: 9,009
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 6837 Post(s)
Liked 4,287 Times in 2,335 Posts
This sport is dangerous! Lot's of equipment designed to maim and injure people. I think I'll go back to couch surfing.
Mojo31 is offline  
Old 04-14-22, 02:31 PM
  #38  
big john
Senior Member
 
big john's Avatar
 
Join Date: Sep 2005
Location: In the foothills of Los Angeles County
Posts: 21,364
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 5746 Post(s)
Liked 5,500 Times in 2,819 Posts
Originally Posted by eduskator View Post
It does make sense! Never thought of that to be honest, but rubbing brake pads on a wheel for an extended period of time must heat the whole thing pretty seriously.
Hot air = increase in pressure = assploding tires!
I tried those peel and stick patches at one time and had one blow off on a steep descent when it got too hot.
big john is offline  
Old 04-14-22, 05:10 PM
  #39  
Kapusta
Advanced Slacker
 
Kapusta's Avatar
 
Join Date: Feb 2017
Posts: 5,822

Bikes: Soma Fog Cutter, Surly Wednesday, Canfielld Tilt

Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 2593 Post(s)
Liked 2,295 Times in 1,297 Posts
Originally Posted by Darth Lefty View Post
How fast do you imagine it's spinning?
By the time you end up in a pileup and coming into contact with a disc, it is not going to be turning very fast. The edge of the rotor is only moving a fraction of the speed of the tires.
Kapusta is offline  
Old 04-14-22, 06:59 PM
  #40  
Darth Lefty 
Disco Infiltrator
 
Darth Lefty's Avatar
 
Join Date: May 2013
Location: Folsom CA
Posts: 13,373

Bikes: Stormchaser, Paramount, Timberjack, Expert TG, Samba tandem

Mentioned: 69 Post(s)
Tagged: 0 Thread(s)
Quoted: 2954 Post(s)
Liked 1,860 Times in 1,211 Posts
The EWS lately did a study about what kind of injuries riders were getting and how severe (in terms of days to recovery). Does road cycling have any similar stats?
__________________
Genesis 49:16-17
Darth Lefty is offline  
Old 04-14-22, 08:02 PM
  #41  
qwaalodge
Banned.
 
Join Date: Jan 2022
Location: Kingdom of Qwaa
Posts: 307
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 211 Post(s)
Liked 78 Times in 61 Posts
Originally Posted by eduskator View Post
It does make sense! Never thought of that to be honest, but rubbing brake pads on a wheel for an extended period of time must heat the whole thing pretty seriously.
Hot air = increase in pressure = assploding tires!
The rim braking heat weakens the rim material (aluminum or CF and keeping in mind, the tire pressure, is pushing hard against the rim edge). A lot worse if the owner did not bothered to replace the rim after the wear indicators have worn out.

And then, the heavier the rider, the higher the tire pressure, the higher chance of blowing out the rim when dragging the brakes in long, hot weather descents. Fortunately, many blowouts seem to happen at the rear wheel which is less dangerous than the front but still very dangerous especially if it happened 40mph downhill.

This is why you hear the advice very often, "do not drag your brakes in long descents". But it doesn't always work for everyone for many reasons and the disc brake is a most welcome tech for that.
qwaalodge is offline  
Old 04-15-22, 04:08 AM
  #42  
Racing Dan
Senior Member
 
Racing Dan's Avatar
 
Join Date: Aug 2015
Posts: 2,117
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 1250 Post(s)
Liked 282 Times in 190 Posts
Originally Posted by Darth Lefty View Post
How fast do you imagine it's spinning?
A lot less fast than you think. Assuming you go down at 30 mph, the edge of the disc, assuming a 160mm disc, is only moving at ((pi*0.16m)/2.15m) * 30 mph = ~7 mph, and that is at about 375 rpm.
Racing Dan is offline  
Old 04-15-22, 06:03 AM
  #43  
seypat
Senior Member
 
Join Date: Oct 2010
Posts: 7,899
Mentioned: 67 Post(s)
Tagged: 0 Thread(s)
Quoted: 2750 Post(s)
Liked 1,917 Times in 1,197 Posts
This thing only weighs 12lbs. Plenty heavy enough to inflict major damage if swung as a weapon. Especially if you're a biscuits and mustard type of person. (that wasn't a rotor, though) Imagine how much damage it or something similar with a thinner blade profile could do attached to a 150lb projectile traveling 20+ mph. That's a lot of ballast with lots of force behind it. It's entirely possible. Not likely, but possible. I still think the chainrings would do more slicing damage. Blunt force, most anything attached to the bike will pack a punch.

seypat is online now  
Old 04-15-22, 06:55 AM
  #44  
Reflector Guy
Senior Member
 
Reflector Guy's Avatar
 
Join Date: Jul 2020
Location: Chicago
Posts: 1,241

Bikes: Bianchi Infinito XE, Via Nirone 7, GT Aggressor Pro

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 569 Post(s)
Liked 1,170 Times in 541 Posts
Originally Posted by seypat View Post
This thing only weighs 12lbs. Plenty heavy enough to inflict major damage if swung as a weapon.

LOL Reminds me of a "meme" we use on another forum..... Brake rotor threads are always a lively subject!

Reflector Guy is offline  
Likes For Reflector Guy:
Old 04-15-22, 07:46 AM
  #45  
Kapusta
Advanced Slacker
 
Kapusta's Avatar
 
Join Date: Feb 2017
Posts: 5,822

Bikes: Soma Fog Cutter, Surly Wednesday, Canfielld Tilt

Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 2593 Post(s)
Liked 2,295 Times in 1,297 Posts
Chainrings are FAR more dangerous than discs. The danger could easily be mitigated to near zero with a dead simple and extremely light ring guard (like a bash ring).

I find it amusing that anyone frets over discs while they don’t think twice about the easily solvable issue with chainrings.

To be real, I don’t think either is worth losing sleep over, but to worry about discs before rings is just asinine.
Kapusta is offline  
Old 04-15-22, 08:05 AM
  #46  
bikecrate
Senior Member
 
bikecrate's Avatar
 
Join Date: Jan 2005
Location: LF, APMAT
Posts: 2,739
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 611 Post(s)
Likes: 0
Liked 368 Times in 212 Posts
Why can't this be tested and put to rest? You could take a dead pig's limb, spin a bike wheel on a stand up to speed, stick limb up to disk and see what happens. Then have barbecue pig limb later. Where's Mythbusters when you need them?
bikecrate is offline  
Old 04-15-22, 08:10 AM
  #47  
WhyFi
Senior Member
 
WhyFi's Avatar
 
Join Date: Jan 2010
Location: TC, MN
Posts: 39,330

Bikes: R3 Disc, Haanjo

Mentioned: 353 Post(s)
Tagged: 1 Thread(s)
Quoted: 20610 Post(s)
Liked 9,279 Times in 4,595 Posts
Originally Posted by seypat View Post
Imagine how much damage it or something similar with a thinner blade profile could do attached to a 150lb projectile traveling 20+ mph. That's a lot of ballast with lots of force behind it. It's entirely possible. Not likely, but possible. I still think the chainrings would do more slicing damage. Blunt force, most anything attached to the bike will pack a punch.
Yeah, it's all about the impact force, and that rotational speed is a bit of a red herring, but I think that this overstates it. The force behind it isn't going to be the full weight of the bike and rider - we're meat sacks loosely attached to the bike at best. Yeah, discs can cause damage in pileup but, as you say, that's the nature of high-speed collisions and I think it's silly how much they're demonized (by some), relatively speaking.
WhyFi is offline  
Old 04-15-22, 08:39 AM
  #48  
seypat
Senior Member
 
Join Date: Oct 2010
Posts: 7,899
Mentioned: 67 Post(s)
Tagged: 0 Thread(s)
Quoted: 2750 Post(s)
Liked 1,917 Times in 1,197 Posts
Originally Posted by WhyFi View Post
Yeah, it's all about the impact force, and that rotational speed is a bit of a red herring, but I think that this overstates it. The force behind it isn't going to be the full weight of the bike and rider - we're meat sacks loosely attached to the bike at best. Yeah, discs can cause damage in pileup but, as you say, that's the nature of high-speed collisions and I think it's silly how much they're demonized (by some), relatively speaking.
Also, unless the target is up against something solid like the ground or a wall to produce an anvil effect, you're going to have a lot of bounce and recoil reducing the blow. Like I said before, it's certainly possible. I'm just not seeing it. More likely the gouge came from something like a protruding axle, a shoe cleat or a pedal. Maybe even the edge of a brake caliper.

You also have a wheel there that will probably hit whatever first. I don't see a direct hit head on from the rotor happening.

Last edited by seypat; 04-15-22 at 08:45 AM.
seypat is online now  
Likes For seypat:
Old 04-15-22, 09:19 AM
  #49  
Darth Lefty 
Disco Infiltrator
 
Darth Lefty's Avatar
 
Join Date: May 2013
Location: Folsom CA
Posts: 13,373

Bikes: Stormchaser, Paramount, Timberjack, Expert TG, Samba tandem

Mentioned: 69 Post(s)
Tagged: 0 Thread(s)
Quoted: 2954 Post(s)
Liked 1,860 Times in 1,211 Posts
Rotational speed and how fast it's spinning is absolutely a red herring. When I put my finger on the disk above I was in no danger because it's not really very sharp but if I fell on it, it could cut something. The cheap Tektro rotor isn't that impressively finished, the edges are not rounded at all. The situation is more akin to a hatchet. That's a lot scarier, they should go with that. But in cycling, calling something a hatchet is reserved for saddles, for some reason.

Somehow no one in motorcycle racing or mountain biking ever has this problem.
__________________
Genesis 49:16-17
Darth Lefty is offline  
Old 04-15-22, 10:23 AM
  #50  
Bearhawker
Full Member
 
Join Date: Apr 2012
Location: Prince Edward Island, Canada
Posts: 252

Bikes: '19 Norco Bigfoot 6.1 (primary ride),'12 Motobecane Turino (killed by dog crash), '12 Trek 3700 Disc

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 130 Post(s)
Liked 107 Times in 64 Posts
Airbags are obviously required. And seat belts to make sure you're positioned properly for the airbags to have maximum safety effect.
Bearhawker is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell or Share My Personal Information -

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.