Is Cervelo R5 a noodle?

Discuss light weight issues concerning road bikes & parts.
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rmerka
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Joined: Wed Mar 06, 2013 4:23 pm
Location: Austin, TX

by rmerka

@ Mario Jr. Chill out man! There's no need to get upset and use colorful language. The OP checked out from his thread judging from his last post. I was just trying to add a little levity by introducing my own un-scientific "noodle test".
Last edited by rmerka on Fri Apr 05, 2013 4:18 am, edited 1 time in total.

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rmerka
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Location: Austin, TX

by rmerka

This thread's like a car wreck. You know you shouldn't look but you keep on doing it. I'm ashamed of myself for coming back again.

by Weenie


thisisatest
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by thisisatest

Even though there is a lot of back and forth on this topic, and the OP has probably gone for good, I'm gonna chime in...
First, I have ridden the r5 and dogma, and dogma2, and dogma65.1, and r3, and old r3sl, and r5ca etc...
As mentioned previously, the video does not depict stiffness, it depicts oscillation. the reason the bars can flex to the left so far is because they're rebounding from being pushed to the right, and the forces are stacking up. A strong enough shimmy can literally rip a frame in two (mostly old school steel, but...).
So what I believe I'm seeing is NOT shimmy, as its not shaking on its own in a complete runaway manner, but it's very close to the shimmy frequency.
The dogma is stiff, but not overly so. I always felt like it was greater than the sum of its parts. I diidnt WANT to like the dogma, but it always inspired confidence. I believe it is well damped in the head tube, possibly damped in the frame in general in torsion but not in vertical compliance. Then it avoids feeling 'dead'. IMO damped vertically = dead.
As for the test in the video being relevant to stiffness, I obviously don't agree. As for "people in the industry" using it and believing it correlates, I'm not so sure. I'd like to hear that straight from them instead of second hand. sometimes important parts are lost in translation. then again, I've met absolute idiots clinging on to myths and folklore in all levels of many, many bike companies and, well, everywhere....

Permon
Posts: 640
Joined: Mon Jun 23, 2008 8:52 am

by Permon

goodboyr wrote:I nominate this thread for the biggest waste of time on this forum. We are no longer discussing the technical issue, just who is smart and who is dumb.....and even that is up for argument! And I don't believe the wheel and headset have been eliminated..........and usually the simplest answer is the right answer. How likely is it that there's a mystery carbon layup issue on this bike, vs a loose headset or a bad front wheel or a dopey test. In any case.................... :noidea:


You are not right.
1) The headset was diassebled twice. It is set perfectly. Absolutely sure the headset is not the issue.
2) the bike was fitted with Bora wheels with perfect hub settings, no play.Image

My quess is, that the frameset is defected. It is very funny how nobody wants to admit this scenario. It looks like everybody believes that Cervelo's products are 100% quality :mrgreen:
Well, as I noticed before, this R5 is a replacement for a substandard R3 (too loose BB shell, so the cups were traveling out of the frame after few strokes of cranks).
So, I am the last one to believe in Cervelo's 100% quality processes....and I am pretty much sure there is alot of people having problems with Cervelos (cracked BB on R3 (2008), cracked hangers on R3 (2011), loose BB shells.....)

davidalone
Posts: 589
Joined: Fri Feb 10, 2012 4:27 pm

by davidalone

thisisatest wrote:Even though there is a lot of back and forth on this topic, and the OP has probably gone for good, I'm gonna chime in...
First, I have ridden the r5 and dogma, and dogma2, and dogma65.1, and r3, and old r3sl, and r5ca etc...
As mentioned previously, the video does not depict stiffness, it depicts oscillation. the reason the bars can flex to the left so far is because they're rebounding from being pushed to the right, and the forces are stacking up. A strong enough shimmy can literally rip a frame in two (mostly old school steel, but...).
So what I believe I'm seeing is NOT shimmy, as its not shaking on its own in a complete runaway manner, but it's very close to the shimmy frequency.
The dogma is stiff, but not overly so. I always felt like it was greater than the sum of its parts. I diidnt WANT to like the dogma, but it always inspired confidence. I believe it is well damped in the head tube, possibly damped in the frame in general in torsion but not in vertical compliance. Then it avoids feeling 'dead'. IMO damped vertically = dead.
As for the test in the video being relevant to stiffness, I obviously don't agree. As for "people in the industry" using it and believing it correlates, I'm not so sure. I'd like to hear that straight from them instead of second hand. sometimes important parts are lost in translation. then again, I've met absolute idiots clinging on to myths and folklore in all levels of many, many bike companies and, well, everywhere....



+1. just because 'people in the industry' test this way, doesn't mean they're right. lots of bike reviewers know nuts about what they're testing. how many half baked reviews do you often read in bicycle mags?
I'll contend that lots of the more 'scientific' tests you see in ride, or in velonews, aren't that accurate either. yes, measuring deflections does give you a more empirical figure to compare against. but thats just the frame. a bicycle is a sum of assemblies, and a problem in a single one affects the whole system.
IMO, most modern bikes are extremely well engineered, any perceived increase/decrease in stiffness, given similar budgets and materials is likely to be less than a 5% change. Much as I hate to say it, but alot of the time it's our minds which magnify these things. the new bike you spent $5000 on is most likely going to feel better than your old one. not saying that there are NO differences, but those differences are rarely going to be able to be distinguished
FYI I am a mech engineer who does FEA testing. not on bikes, but the physics is similar. the facts don't lie. I may be starting to do FEA testing for a custom framebuilder within the next year or so, maybe I'll report back then.

for the OP's case, it's difficult to tell. so many things could be happening. if you've ruled out everything and something is still wrong, and you've checked the frame then chacnes are it would be a geometry issue.

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euan
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Joined: Sat Sep 05, 2009 11:20 am

by euan

Plenty of people have pointed out that its either your setup or a faulty frame.

This thread is just useless except for mud slinging matches now.
"Step forward the climber and all those who worship at the altar of lightness" - R. Millar

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bikerjulio
Posts: 1901
Joined: Fri Dec 11, 2009 10:38 pm
Location: Welland, Ontario

by bikerjulio

Permon, your PF30 thread came back to life :lol: Why don't you fill us in on how that all worked out? (same bike, right?).
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

User Name
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Joined: Tue Jun 07, 2005 3:32 pm

by User Name

Yeah, any updates? :D

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Liggero
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Joined: Sat Feb 18, 2012 11:49 pm
Location: Netherlands

by Liggero

it's either a defective frameset, or a defective customer. hope it's the first option, but i´m afraid it's more likely to be the second one...
Happy Trails !!!

justkeepedaling
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Location: by Crystal Springs (Sawyer Creek Trail)

by justkeepedaling

Have you checked your stem? FSA stem is pretty noodly itself

GT56
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Location: Switzerland

by GT56

justkeepedaling wrote:Have you checked your stem? FSA stem is pretty noodly itself


+ 1 on the stem, I noticed a big increase in stiffness going from an R3 with FSA stem and bar to an R3 with 3T stem and bar

Donn12
Posts: 23
Joined: Wed Aug 15, 2012 2:17 pm

by Donn12

I was set on a new r5 and my LBS convinced me to look at a Dogma 65.1. I rode both and decided on the dogma immediately after I started the test ride. Absolutely no comparison in ride/handling/feel/stiffness. I fully expected it to be 2lbs heavier based on how it felt but it was about 1/2 pound. The R5 felt fragile by comparison and I love Cervelos!

stanseven
Posts: 63
Joined: Thu Feb 28, 2013 4:25 am

by stanseven

Donn12 wrote:I was set on a new r5 and my LBS convinced me to look at a Dogma 65.1. I rode both and decided on the dogma immediately after I started the test ride. Absolutely no comparison in ride/handling/feel/stiffness. I fully expected it to be 2lbs heavier based on how it felt but it was about 1/2 pound. The R5 felt fragile by comparison and I love Cervelos!


The difference between just the frame sets is a little over a full pound. Pinarello's published weights are misleading because they are for an unpainted frame without all the hardware (shell for BB, bosses for cages, etc.). Depending on the specific size, it's about 500g. You also get some extra weight between the forks too.

Permon
Posts: 640
Joined: Mon Jun 23, 2008 8:52 am

by Permon

Donn12 wrote:I was set on a new r5 and my LBS convinced me to look at a Dogma 65.1. I rode both and decided on the dogma immediately after I started the test ride. Absolutely no comparison in ride/handling/feel/stiffness. I fully expected it to be 2lbs heavier based on how it felt but it was about 1/2 pound. The R5 felt fragile by comparison and I love Cervelos!


It is exactly what I was writting from the very begining. R5 is fragile......at the front end, the BB stiffnes is OK.
Pinarello DOGMA has a rock solid front end.
Looks like those +500g are there for a reason.
Last edited by Permon on Sun Apr 21, 2013 12:07 pm, edited 1 time in total.

by Weenie


Permon
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Joined: Mon Jun 23, 2008 8:52 am

by Permon

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