Archive for April, 2016

I don’t know what the whole fuss about the dangers of disc brake rotors in pro road racing is all about. I may not be the fastest road racer on the planet, but I’ve had my fair share of experience in a road racing field and same goes for disc brake use.

It blows my mind how little these pros actually know about disc brakes, pros/cons, or how to even use them properly.  I guarantee you more than half of the pro peloton at this year’s Paris Roubaix probably have never used a disc equipped bike in their life time.  Especially the ones who remember racing on bikes that only had 3 gears…

To clarify, I really feel bad about those riders who were injured during this years Paris Roubaix, and I wish them a very speedy recovery.  Yes, road racing has it’s dangers.  I’ve crashed on the road more than I care to admit, and crashing at speed makes it even worse.  Throw in some cobbles, 200 of some of the strongest cyclists in the world, and a pretty big trophy at the end of the race, and you end up with these dangers compounded.

This year is the first full year (or was until about 3 hrs ago) where at least the pro peloton had the ability to ride a disc brake equipped road bike in any UCI sanctioned road event.  Yet you can easily get away with racing an old school cantilever equipped CX bike with carbon rims in a rainy road race no problem, but that’s another story.  Honestly, I cannot tell you what the solution to this whole debacle is, I’m just here to point out some VERY obvious facts.

What actually happened?

First off:  If you read Ventoso’s word for word account of what happened, his recount of the crash goes something like this:

Let me take you to 130km into the race: into a cobbled section, a pile-up splits the field, with riders falling everywhere. I’ve got to break [brake] but I can’t avoid crashing against the rider in front of me, who was also trying not to hit the ones ahead. I didn’t actually fall down: it was only my leg touching the back of his bike. I keep riding. But shortly afterwards, I have a glance at that leg: it doesn’t hurt, there’s not a lot of blood covering it, but I can clearly see part of the periosteum, the membrane or surface that covers my tibia. I get off my bike, throw myself against the right-hand side of the road over the grass, cover my face with my hands in shock and disbelief, start to feel sick… I could only wait for my team car and the ambulance, while a lot of things come through my mind.”

Ok, so he remembers his leg ‘touching’ the back side of the bike of the rider in front.  I have a hard time believing that he himself remembers exactly what his knee touched.  But regardless, lets move onto some other alarming facts.  Did he ever mention anything about spokes?

Ventoso goes on to talk about the number of disc brake rotors present in the peloton for this years Paris Roubaix, 32.  Meaning 2 full teams of 8 all had disc brake bikes.  8 x 2 (wheels per bike) x 2 (# of teams) = 32.

Disc Brake Rotors:

Only those who have used disc brakes a lot would understand the true dangers and/or subtleties of riding with disc brakes.  For example, if you are riding down the Stelvio, or a MTB trail descent next to the Stelvio, your rotors will heat up like no body’s business by the end of the downhill, so you better stay away.  Yet if you are on a long road ride where you only use your brakes (lightly I might add) to take a 90 deg corner every 5 mins, it will be highly unlikely that your rotors will heat up hot enough for the hot rotors to be any help in cutting through your skin.

Bladed Spokes:

So how many bladed spokes do you think were present in this year’s Paris Roubaix Peloton?  Of all the bikes I could see from photos of the race, and the status of the types of wheels in the current pro peloton, I imagine EVERY team had aero wheels with bladed spokes (as flat box regular spokes are essentially a thing of the past), but just for safety sake lets say 5% of the wheels out there used normal non-bladed spokes.  As most wheels are carbon, this allows less number of spokes per wheel, but lets assume that the average number of spokes for a wheel is 20 (a far cry from the 32 on some wheelsets, so this ends up being a very safe estimate).  So the total number of bladed spokes in the peloton would have been about 200 (# of riders) *2 (wheels per rider) *20 (average # of spokes per wheel) = 8000 (factoring in the 5%) = 7600 bladed spokes.  A whole lot more than 32, or am I wrong?  That’s over 200 times more likely to come in contact with a more dangerous spoke than a rotor.  ***My initial math was of by one whole digit.  Which further makes the case.  Thanks to Gary for pointing this out!

Spokes vs. Rotors:

Bladed spokes are always more narrow than rotors further adding to the danger of the bladed spoke.  Most bladed spokes (and even rotors for that matter) are measured in units smaller than mm’s but lets say for the public sake that an average bladed spoke ends up being around 1mm wide.  When the average rotor comes in around double that at 2mm’s.  Adding to the fact that bladed spokes are called ‘BLADED spokes’ for a reason (meant to be as aerodynamic as possible in order to cut through the wind with minimal resistance like a blade) I don’t know of any rotors that are designed with this in mind.  Most of them are all flat at the end further reducing their ability to cut through skin.

Do rotors heat up when braking and cut through skin when red hot?  I don’t know if you’ve seen the recent GCN episode talking about the differences between disc brakes and canti’s but for shits and giggles, it’s a must watch.  Make sure you get to the middle part when they use a sausage to show you the dangers of the rotors, er… I mean bladed spokes…

Not only are bladed spokes more dangerous when comparing directly to disc rotors, you need to keep in mind that spokes are travelling at nearly twice the speed of the rotor and are always moving.  Lets use this image from http://physics.stackexchange.com/ to show what I’m talking about.

If the bike ends up moving at 40km/hr (v) which is roughly the speed of the rotor given how small it is and close to the hub, then the part of the spoke that is closest to the rim end up moving at almost double this speed, or 80km/hr (2v)  I don’t know about you, but this trend is getting a bit alarming for me…

Summary:

Ok, now taking all this into mind, on top of the fact that Ventoso doesn’t recall exactly what he ran into, nor doe they say anything about the details of his Etixx- QuickStep buddies incident, who’s to say his knee didn’t ‘touch’ a spoke.  The dangers in the peloton are real, yes, but the inexperience (when related to disc brakes) of the majority of these pros is portraying a very twisted view on what the dangers truly are.

If the majority of the people involved in cycling at this higher level are really just worried about the compatibility problems, and the fact that they know they will have to wait longer for a wheel than if they just stick with the tried and true rim brake wheels, then why are they shooting technology advancement in the foot by playing the safety game.  Or is cycling the next soccer (or football for those outside of North America) and we are just looking for the next thing to blame in order reduce the amount of suffering we have to go through to win a bike race.  Hey what do I know, I’m just a cyclocrosser in the ‘off-season’ who’s 2 beers into the night…