Shimano’s New Disc Road Brakes

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I saw this article at about Shimano’s new road specific disc brakes. I kind of hate the whole idea of it, switching all my wheels to disc. I didn’t do it for my cross bikes yet and guess I’ll wait to see if it is going to catch on before I think about committing.

I haven’t ridden them yet personally. The review was good. I don’t think that the braking on road discs can be as good as rim braking on aluminum rims. It has to be better than braking on carbon rims.

Shimano usually does it right the first time when they delve into a new product. Way righter that nearly all other companies. I’m sure it will be the same with these brakes.

I can’t applaud them for their choice for celebrity guess speaker. None other than the one of the worst descenders/bike handlers in he upper echelon of the pro field, Andy Schleck. Here’s what Andy had to say about the new brakes

Road racer Andy Schleck, guest of honour at Shimano’s press camp, had some positive things to say regarding the disc vs rim debate.

Plenty of people have claimed that pros don’t need or want them. But Andy had a different take: “If you’re descending in the wet, especially on lightweight carbon rims then there is often water on the rim braking surface. That means you need to brake early, to give time to clear that water. In turn, that often means you are dragging the brake into corners with no guarantee of when braking is going to happen.

“On a long descent in hot conditions, they way a brake feels at the top is different to how it feels at the bottom once the rim has become hot. Mostly this results in a ‘grabby’, sudden brake feel.”

Wow Andy, the rim gets wet when you’re descending in the rain. And in hot conditions, I very much doubt the rim is any hotter at the bottom of the descent than the top other than the energy you’ve put into it by trying to slow down.

Maybe Shimano brought him in because they think that he has the most to gain from the products? But, I wouldn’t be using him as an authority on how to use your brakes properly descending. Or maybe Shimano was brillant, because Andy uses his brakes more than just about anyone else out there.

Here's Andy in perfect Andy form.  Check out his head position.  And how it is different than Cunego's.  Plus, he has a ton of front brake on when his wheel is already committed to the corner.  Man, no wonder he can't descend worth a shit.

Here’s Andy in perfect Andy form. Check out his head position. And how it is different than Cunego’s. Plus, he has a ton of front brake on when his wheel is already committed to the corner. Man, no wonder he can’t descend worth a shit.

26 thoughts on “Shimano’s New Disc Road Brakes

  1. DJLind


    I agree wholeheartedly about everything you said. There are so many unknowns about road disc brakes and personally I will be waiting to convert all of my bikes and wheels over until the UCI approves their use and the pro peloton is racing on them.

    The picture of Schleck descending is indeed a perfect example of poor form, except I think you’ve got the wrong Schleck there. I’m pretty sure that is Frank….not Andy. But the point remains – neither brother is an appropriate authority on brake performance while descending!


  2. Skippy

    Thought the racer looks more like frank , but then some News Networks tend to put ” foot in mouth ” when giving info !

    Check my blog for latest on the need for GOOD brakes , as seen in Sydney , early today ” sh#t happens “!

    Doubt i will be replacing my brakes with Discs , even if given to me ?

  3. Ted Lewandowski

    Rims most certainly get hot on descents that is why you had to be real mindful of your braking when everyone was riding sewups as the glue would actually heat up and you could literally throw the tire right off the rim – but I imagine the last time a pro team had sewups was probably in the late 1990’s.

    Domestically that was not a big problem – but it was certainly something to be aware of during the Giro or the TdF with long mountain descents.

    I also don’t see anything wrong with Frank’s position in this photo – and no one knows the radius of the curve or turn to say so otherwise from this brief snapshot – if you notice the Lampre rider behind him – he is even braking more than Frank taking the inside line.

  4. DarkLord

    Why bother with disc brakes? Because the bike industry makes money off pushing the next big thing, even if it’s completely unnecessary to win races. Case in point: DI2 and EPS. They are the “Viagra” of shifting by solving a problem that’s way over-blown (pun not intended). Unless you are bombing down mountains on a regular basis in your racing or riding, who really needs disc brakes and are you really going to dive into corners that much later than you can using caliper brakes to gain an advantage? What’s next, disc brakes with ABS so you can just ride them through the entire corner? (hmm I may be on to something with that one)
    When people buy into the “oh I need disc brakes” crap, they will, inevitably, have to buy a whole new bike as well. Voila’! The bike industry will make millions.

  5. channel_zero

    Please tell me the last time a bike race was a braking contest. Modern calipers are more than sufficient for the job.

    I know, I know, that jerk channel_zero is a real bike geek buzz killer.

  6. Brian paul

    Well dang nabbit why do we even need this new fangled shifting we were fine with fixed gears in the early 1900’s and dang why do we need these new fangled helmets? We got serious head injuries and we liked it. darn and drat and 32 skiddoo.

  7. The Cyclist

    Yeah… f*** helmets. They are completely destroying the cycling of today. Now you can’t see who’s who there. Not even in high def. Is that Andy? No, it’s Fränk. Hell no… it’s Andy!! Anyone can see that. WTF!!!? It’s Fränk! Nope. Andy.

    Sorry, it’s neither Fränk nor Andy. It’s just a stupid oversized helmet with shit for handling going down that bend.

  8. Bill K

    I’m sorry to say that I’ll never be a Cat 2 and need the use of carbon wheels. Same for Di2. My “retro” 7800 works just fine.

    Think of half the field with disc brakes…..Then think about a track event with half the riders with brakes.

  9. Paul

    He likes them because they’re more idiot proof and will help him stay close to better riders. The dude can’t even shift unless it’s idiot proof also. You started riding when cycling required a bit more skill and cleverness.

  10. Jason

    I don’t want disc brakes anywhere near any road events I am doing. I may be paranoid, but I just see dudes getting carved up by rotors when the inevitable big pile up happens.

  11. Ted Lewandowski

    Yes – that is when you were riding your tricycle in the cul-de-sac so your memory might be a bit fuzzy – idiot.

  12. Thomas

    Ted so if pro riders are not using “sew ups” or tubulars as i call them what tires are they running? Asking for an idiot?

  13. channel_zero

    Ding! Ding! Ding!

    Track racing with brakes is a perfect analogy. Or, is that a metaphor…

    Crashtastic fun just around the corner. That means more equipment sold, so it’s all good.

  14. Rich W.

    Disc brakes stop better in all conditions than rim brakes. You all act like you’ve have taken a great moral stand against the evils of modern marketing and are the last champions of the purity of the sport by speaking out against disc brakes. Carbon fiber everything=check. 10 or 11 speed=check. Power meter=check. GPS/Strava=check. 15 lbs bike=check. Disc brakes=NO WAY! Get over yourselves.

    BTW, either Schleck brother will drop any of you on any descent. Yes, even you, Steve!

  15. GN

    Well if disc brakes become UCI legal and Andy Schleck becomes one of the peloton’s best descenders we will have proof!

    In Kansas, disc brakes might not become a instant best seller, but everyone knows that carbon brakes are super grabby and poor braking surfaces. What disc brakes actually offer is modulation and the ability to brake without locking up the wheel. Seems like disc brakes could “potentially” reduce some of the bad crashes in the pro peloton we are seeing now, especially since guys are adding weights on their frames to take them to the UCI limit. I’m pretty sure 15 years ago when everyone was on alloy rims, crashes were not as bad, and we know everyone in Europe was juiced and on EPO, so the speeds were faster then! My only concern would be crashing on a disc rotor much like crashing in other sharp spokes. Does anyone remember Spinergy’s and some of the nast body cuts that resulted from crashes with them?

  16. Steve Tilford Post author

    Rich-I can assure you that your last statement is incorrect. They both do so many things wrong descending that I could stay with them on clinchers with 50 psi. This isn’t bragging, it’s just a fact.

  17. PM

    Road braking is signficantly different that ‘cross/MTB braking. Skidding a turn in ‘cross/MTB is relatively normal, skidding a turn in road racing typically leads to crashing.

    Braking (w/o skidding) is the conversion of kinetic energy to heat. The governing physics equation is Ke = 1/2*mass*velocity^2. The differences in velocity (and skidding) between road and ‘cross/MTB is a big issue.

    Compare a 65 kg rider on a road bike (9 kg) at 80 kph (22.2 mps) vs. same rider on a MTB (11 kg) at 40 kph (11.1 mps). Kinetic energy of the MTB rider = 4682 kJ. Kinetic energy of the road rider = 18235 kJ.

    3.8x more kinetic energy and builders are pushing 140 mm rotors to replace a 700 cc rotor (i.e. rim brake)? If Shimano has figured out the heat disapation issue – bravo to their engineering team, however, the tire contact patch remains the same and still don’t want to skid the turns.

    The case against road discs is: more kinetic energy with smaller rotors (vs. rim brakes or MTB discs), same tire contact patch and preference not to skid will mean more crashes and cooked brakes. All for more ‘modulation’ (which is a learnable skill on rim brakes).

    If you believe the math above, road bikes should be equipped with 200 mm discs – not the smallest ones available.

  18. GN

    Skidding (road/mtb/cross/motor cross/car on ice/etc) = uncontrolled sliding = bad. I’ve ridden plenty of trails where if you skid at all, your a goner, just MTB in the Alps.

    Your missing one very critical difference between road and mtb in your little equation and your concern with heat. Cooling and airflow. Higher velocity keeps more air hitting the surface of the rotor and keeps the surface much cooler.

    One other point. Traditional brakes, the same power is available for a 100lb woman as a 300lb man, there is no way to dramatically change the braking power. With disc, your 100lb woman might be on 140mm rotors, but a shop can easily upgrade other rides to 180mm rotors.

    We have the heat issue with rim brakes today all the time. Larger riders routinely blow tires off rims where I live and Velonews recently did a story a year or two ago regarding this. So heat is as much or more of a issue currently, especially on carbon rims. I know several 250lbs riders who have now switched to hydro disc to eliminate rims overheating coming back down the mountain into town. Personally I’ve ridden down our 4,000′ road descent on my full hydro road disc’s (140mm) with no issues, however I’ve had 203mm MTB disc completely discolored after a 10 min practice ride on a DH track more than once.

  19. PM

    More air hits a 140mm rotor than a 700 cc rim? The rim has a much larger surface area.

    Carbon clinchers have been known to blow tires off – not alloy rims. Again – the inability to effectively dissipate heat plagues both carbon rims and road disks. The ‘road disk’ revolution is designed to try and prevent a return to lower profit margin wheelsets.

    Braking power is irrelevant – can easily skid a road tire using either system – the ‘grip’ of the contact patch governs this part of the equation (friction).

    Braking modulation is the only upside – consumers can decide for themselves whether an entire new non-compatible bike/wheelset is worth the expense.

  20. dave

    Ted…you never answered the question posed by Thomas…..”if pro riders are not using “sew ups” or tubulars as i call them what tires are they running?”

    Do you really think that professional riders use clincher tires?? If you do then you really need to think about who you call an idiot.


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