# 2011 Roubaix use of Zertz...hang on people



## nealrab (Aug 6, 2002)

Well I guess I'll get this one started...again. Unite all skeptics who believe Zertz inserts are sorta eye candy and serve no useful purpose in a bike frame! I'm ambivalent so therefore am excluded...but Spec has now fueled the doubters with the "screw-on" version of the Zertz into the seat stays. Pics on velonews site, but apparently it's a "cost-cutting" move since frames can be made in a more traditional mold without the integrated Zertz devices.
It seems intuitive that screwing/bolting on a "vibration dampening device" would offer zero benefit in that capacity. Where are the Spec engineers to help us gullible roadies understand this change? Were they always just hype/nonsense or is the new set of frames a misguided alteration with no explainable reason? I think we need some sort of rationale for the 2011 version of the Roubaix or else we're just not gonna buy any of these any more...OK, maybe we will but we're not gonna be happy about it or convinced that we did the right thing. We need to know...what is the true meaning of Zertz???


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## purdyd (Jun 18, 2010)

nealrab said:


> It seems intuitive that screwing/bolting on a "vibration dampening device" would offer zero benefit in that capacity.


it may seem 'intuitive' but it will still dampen vibrations 

how much and could you tell the diference? hard to say

you could tap the fork and measure the vibration using an accelerometer with and without the Zertz

or you could simple ride it with and without Zertz and see if you notice a difference, since they now screw in

my guess is that the Specialized engineers have already done this


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## ukbloke (Sep 1, 2007)

Here are the new front and rear Zertz inserts:



















What a crock!


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## nealrab (Aug 6, 2002)

Maybe I can screw in a photo of Contador and it'll give me wings to fly over all climbs...seriously, how can these work at all? I'd really love to see the test data or vibrational analyses on this design. I'd be stunned to see any true benefit to dampening anywhere on the bike due to a screw-in Zertz elastomer.


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## ukbloke (Sep 1, 2007)

Well, you can dampen vibration simply by strapping dead weight onto the vibrating structure ;-) Maybe they did some complicated CAD analysis to find the point of max vibration and added the weight there. If the structure was uniform with nodes of no vibration at the axle and close to the brake-mount this would be half-way between the two nodes. But since the fork is tapered this moves the point closer to the axle, say one third up the fork. Done! It would be a lot cheaper to mount a knog onto each fork leg and the seat stays ...

I think Specialized has "jumped the shark" on this one.


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## penn_rider (Jul 11, 2009)

It may be that they are able to get the dampening without the zertz and are introducing the crew in type before they nix it all together. I noticed in one image of the bike Cancellara rode in the Roubaix did not have the inserts and it was said to be a Spec Roubaix..

What do I know,, I am tired and may be dreaming...


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## roscoe (Mar 9, 2010)

so were the old ones just friction fit in the hole in the tubes? 

I think there's a bit more cynicism than there should be on here, I'd imagine these probably do the same thing the old ones did, which I guess is probably up for debate as well 

the fact that there are screws is not enough to convince me that these will react differently than the old ones, there are many ways to land those screws in the insert that would still allow freedom of movement of the insert


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## Lazy Spinner (Aug 30, 2009)

What does it matter? Buy it, don't buy it. The Zertz do not add $500 or 200 grams to the bike so I can't understand what all the fuss is about.


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## ukbloke (Sep 1, 2007)

penn_rider said:


> It may be that they are able to get the dampening without the zertz and are introducing the crew in type before they nix it all together.


That's it! The Roubaix SL-4 will use a special lay-up of high-modulus pre-reg carbon in the same area to achieve 17% more damping than the elastomers with a 23g weight saving. They can call them Carbon Zertz, but since they are on the inside you won't see them just a funny wavey wiggle in the forks and seat-stays.


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## ukbloke (Sep 1, 2007)

Lazy Spinner said:


> What does it matter? Buy it, don't buy it. The Zertz do not add $500 or 200 grams to the bike so I can't understand what all the fuss is about.


Because it is fun to take the piss out of the marketing spiel!


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## darkest_fugue (Mar 14, 2009)

i dont believe it makes much of a difference if any, i dont even buy into the damping characteristics of a carbon frame anymore, i had a carbon seatpost with a zert in it, changed it for an aluminium one, no difference nada zip nothing,

my frame is an 09 roubaix elite, one of the cushiest with its fact 7 carbon and zertz apparently, ive learned its all in the tyre pressure, its a bone shaker on hard tires im not kidding, itll shake the fillings out of your teeth, a little more tyre compliance it rides like a sofa on wheels, you ride with hard tires the zertz and carbon frame to nothing to soften the ride, i love the bike but im not a believer!!!


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## purdyd (Jun 18, 2010)

When i was in college we had a lab where we would place an accelerometer on a beam and rap it and watch the vibration, then we would put a portion of a special elastomer tap on the beam and rap it again

bottom line, it reduced the vibration

my guess is that in a lab you would see a difference Zertz or no Zertz

i came across this white paper on specialized site - notice at the end they are measuring vibration at the axels and comparing with vibration at the stem and handlebar

http://www.specialized.com/OA_MEDIA/pdf/Witchcraft.pdf

now can you really feel the difference with without zertz and is it just marketing? i think people are right to be skeptical


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## a_avery007 (Jul 1, 2008)

just a another way to differentiate product.


saddle, bar tape used, size of tires, choice of tires, pressure or tubeless will have way more effect than the hYpE the roubaix uses to address comfort...


won't even go into frame design or materials..lol


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## livestrong7 (May 17, 2009)

Smoother is faster. That was the Specialized motto as it developed the Roubaix and it used the cobbles of the legendary Paris-Roubaix Spring Classic as the testing ground. 2010 winner Fabian Cancellera claims the Roubaix SL3 feels as stiff as his Tarmac SL3 only much smoother on the cobbles. This year, the Tour de France rolls over those cobbles on stage three, and many riders on Astana and Saxo Bank will be aboard Roubaix SL3s.

Eliminating vibration and jarring on rough roads and finding the highest level of performance for the largest number of riders was the design focus. That put compliance above all else. Specialized improved its Zertz inserts and engineered the stays for a degree of flex with nearly 6 mm of vertical deflection or flex.

It all starts with the seatstay design. Rather than using a complete cutout, *Zertz inserts *are now mechanically fastened to the stays. The increased tension of pressing them into the frame provides greater consistency and improved durability across the board. A new stay molding with one bladder per leg was also developed for a higher level of compliance. The stays have a new 3D shape which hourglasses from the dropouts to the seat tube to further enhance compliance while adding additional side-to-side stability. Since compliance seems the opposite of high performance, overall stiffness had to be addressed even further. Specialized did this by using the same one-piece top tube/head tube/down tube mold as the Tarmac SL3, its top of the line race road bike. The "Cobra" has a dramatically wide and thin top tube. At the head tube-top tube junction, the top tube is actually wider than the headtube's circumference. This eliminates flex in the joint and eradicates the need for additional material or internal bridges. Specialized also has a proprietary bearing size that's less than 1 1/2" (too stiff) and more than 1 1/8 (not stiff enough.) The lower bearing is raised above the fork crown for better fiber alignment and increased strength in the fork.

Another focal point on the Roubaix SL3 is power transfer. Specialized went with a one-piece, oversized bottom bracket shell and chainstays. Press-in bearings eliminate the internal alloy insert and the elimination of a tube junction increases stiffness for better load transfer. The bike definitely delivers as promised. When the pace heated up near the summit of Ute Pass on the first day, the Roubaix felt more like a Tarmac than any previous Roubaix. On the high-speed run into town it retained that race-bike aggression but imperfections in the road were easily chewed up and shaken off by the frame. Overall compliance was impressive even at speeds near and over 30 mph.

Other noteworthy additions include internal cable routing for mechanical cables as well as Shimano Di2. The same molds and manufacturing process trickle down to the Pro and Expert level machines.

Source:
http://www.bicycling.com/bikes-gear/bikes-and-gear-features/quantum-leap-roubaix-sl3


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## a_avery007 (Jul 1, 2008)

did not Fabian win it this year on a Tarmac?

oops that was Flanders...lol


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## ukbloke (Sep 1, 2007)

a_avery007 said:


> did not Fabian win it this year on a Tarmac?lol


No, it was definitely a Roubaix SL3 though it appeared to have a team geometry (e.g. shorter head tube).


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## hiah (Jun 5, 2007)

Would anyone be willing to run an experiment? I've been researching noise-cancelling materials for cars (stuff from 2nd skin audio and dynamat). When you look into the science behind those products, they don't block or absorb noise, they absorb vibration across a broad spectrum, which is what transmits noise from the outside of the car to the interior. All of these products are just butyl(spelling?) rubber with adhesive backs and maybe a thin layer of foil on the other side.

My thinking is that if you stuck some of those on the frame/fork of a bike, that it would absorb the vibrations as well. Granted, depending on the bike, it may be tough to find a place to put them that wouldn't be easily visible. Has anyone tried this before?


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## ukbloke (Sep 1, 2007)

So I should just wrap my bike with old inner tubes and aluminum foil? I'd be too afraid of ending up on bikesnobnyc if I rode around like that!


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