You can't cut your calf on a chainring?

---

----------------------------------------------------------
Zen and the Art of Triathlon. Strava Workout Log
Interviews with Chris McCormack, Helle Frederikson, Angela Naeth, and many more.
http://www.zentriathlon.com

When pros crash, they're usually in the big ring and the chain helps protect...besides, chainrings usually don't keep spinning at high rates during a crash. It's the spinning edge that is the danger (as any shop mechanic will tell you.)

When was the last time you heard of a pro rider being taken to the hospital to surgically repair a chainring injury? And EVERY bike has a chainring. Only a small percentage of the bikes at P-R had discs.

---

http://bikeblather.blogspot.com/

I suppose we could actually wait and let it get passed the "reportedly" stage before assuming it was the disc brake.

---

Ian

If he'd had disc brakes he could have avoided the crash altogether.

I wonder why they machine disc rotors with two quite sharp 90 deg edges? And I wonder if this accident would have been prevented if the edge of the disc was fully rounded or radiused?

---

Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook
--

I suspect radiusing the full edge may actually make it more dangerous when spinning...sounds like something for a Mythbusters-like test using pig parts.

---

http://bikeblather.blogspot.com/

I bet the nature of the injury could be a big clue in determining that...

---

http://bikeblather.blogspot.com/

You forgot the pink font.

---

http://bikeblather.blogspot.com/

That makes sense, but then why don't they radius both of the edges? Or radius them more?

Sounds like they're gonna start ...


( totally off topic, but is it just me, or is the advanced editor on this forum broken ... ? )

---

Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook
--

Yep, I cannot get the advanced editor to work either. Have to switch to basic

---

Dave Campbell | Facebook | @DaveECampbell | h2ofun@h2ofun.net

Boom Nutrition code 19F4Y3 $5 off 24 pack box | Bionic Runner | PowerCranks | Velotron | Spruzzamist

Lions don't lose sleep worrying about the sheep

The sharp edges, along the various waves, cuts and other contours, are designed to "machine" the pad to keep it clean and flat for more consistent braking and less noise...

---

"I'm thinking of a number between 1 and 10, and I don't know why!"

A disc is only spinning at ~1/5 the edge velocity at the tire. I don't think that the rotation of the rotor is a significant factor in cutting injury after considering a fall onto the sharp rotor edge.

I think that at a minimum the disc outer edge should be fully radiused. A 2mm rounded edge is dramatically less likely to create an injury than the sharp edge currently on discs. It would also be prudent to have a solid disc or one with no apertures where a finger could be trapped.

People are crashing all over the place in cyclocross with disc brakes.

Edit: Disk to disc per grammar comment by James Haycraft

Another option is to ban disc brakes and continue with the proven technology of rim brakes :)

Cyclocross probably has a few things going for it in terms of disc injury risk. Slower speeds, more spread out riders leading to fewer pileups and more clothing.

They could blunt it by using a piece of rubber. And then inflate that piece of rubber to make sure it's properly round and has a soft balloon shape to prevent injuries.


It is for me too. I had to use the basic one. I couldn't find the sarcasm button either :) Just "b", "u", "i",...

So on a flat road that's 10 km/h. On a downhill it'll be 20 km/h (but large pileups are less common on a twisty downhill) That's not nothing. We could test it with a piece of salami (and then eat the result...)


If you do that you remove a lot of the mud shedding abilities. The apertures are there to prevent premature wear of the pads. That's important in Paris Roubaix. (edit: the mud apertures are tiny)

The apertures might be important in wet weather riding too.

The holes are traditionally good for heat dissipation.

Just in January... http://www.cyclingweekly.co.uk/...d-disc-brakes-208497 And people like you tried to turn it against discs when it's purely a chainring injury

I think its time we all start racing in full leathers gp style ;-)

cobbles themselves create a few injuries

---

'to give anything less than the best is to sacrifice the gift'...Pre

Proven in what regard?
Both brakes have been proven to slow down the bike. Disks have, I believe, been proven to do it better. Have disks been proven to cause more or worse injuries? Not that I know of.....it there were any examples, perhaps they'd be used instead of hijacking chainring injury cases and suggesting a correlation!?
People have been falling off mountain bikes for years, not mass peloton crashes perhaps but regardless, have there been huge numbers of horrible disk based injuries?

Brake rotors on the mountain bike haven't been an issue when I have crumpled up on fast downhills. Last night I filleted a couple knuckles on some bladed spokes, them bastards can get you.

---

Pactimo brand ambassador, ask me about promo codes

It's funny you should say that. I'm not sure if you're referencing this video or it's just a coincidence
https://www.youtube.com/watch?v=JplymlruPZ8

Cut to 2:45[/reply]

Are you doing those downhills while in a pack of riders?

---

http://bikeblather.blogspot.com/

Nope, but I have seen some pretty spectacular pile ups and never heard of a rotors severing limbs, things I have heard tearing people up include: the ground, broken cranks, broken pedal spindles, broken handle bars, broken frames, the ground, trees, fences pretty much everything save the spinning bits (spokes and rotors).

---

Pactimo brand ambassador, ask me about promo codes

Exactly...which points out the large differences in use cases...something which should always be kept in mind. Just because a certain technology is good for one discipline of cycling, it doesn't mean it's automatically appropriate for another.

---

http://bikeblather.blogspot.com/