2021 Road Bike Stiffness Chart

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MagicShite
Posts: 455
Joined: Sun Jun 26, 2016 3:33 pm

by MagicShite

wait am I reading the charts wrong or were the older aeroads more compliant at the seatpost than the new LOL-AEROAD?

What's the point of the S shaped seatpost then?

tomtom
Posts: 372
Joined: Sun Oct 31, 2010 9:01 am

by tomtom

MagicShite wrote:
Sat Mar 13, 2021 11:41 am
wait am I reading the charts wrong or were the older aeroads more compliant at the seatpost than the new LOL-AEROAD?

What's the point of the S shaped seatpost then?
The seatpots is NOT s-shaped but maybe will be. I flexes more because of a lower clamping point and an aeroshell. But the numbers show a strange difference I would say. I have both bikes but the CFR feels much more comfortable in the saddle (although a part of that can be the difference between 25 and 28mm both on 6.0 bar)
Ultimate CFR
Aeroad CFR
Grail CF

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MagicShite
Posts: 455
Joined: Sun Jun 26, 2016 3:33 pm

by MagicShite

tomtom wrote:
Sat Mar 13, 2021 1:07 pm
MagicShite wrote:
Sat Mar 13, 2021 11:41 am
wait am I reading the charts wrong or were the older aeroads more compliant at the seatpost than the new LOL-AEROAD?

What's the point of the S shaped seatpost then?
The seatpots is NOT s-shaped but maybe will be. I flexes more because of a lower clamping point and an aeroshell. But the numbers show a strange difference I would say. I have both bikes but the CFR feels much more comfortable in the saddle (although a part of that can be the difference between 25 and 28mm both on 6.0 bar)
I mean coming from the Propel Disc I certainly would say it's more tire than just the seatpost.

I'm on a TCR Pro Disc right now and it didn't feel that different to me. I run 29.5mm effective width tires at 74psi rear.

spartan
Posts: 1816
Joined: Fri Sep 03, 2004 2:52 am

by spartan

so the peak TARMAC was the SL6 lighter / stiffer/ more compliant than the SL7. yes SL7 is at best 3-5 watts faster but marginal.
Current Rides:

2023 Tarmac SL7 Di2 9270
ex 2019 S-works SL6
ex 2018 Trek Madone SLR Disc
ex 2016 Giant TCRAdvanced Sl
ex 2012 Trek Madone7

openwheelracing
Posts: 379
Joined: Thu Jan 28, 2021 6:41 am

by openwheelracing

Pinarello....ouch.

spdntrxi
Posts: 6021
Joined: Sat Jul 20, 2013 6:11 pm

by spdntrxi

openwheelracing wrote:
Sat Mar 13, 2021 3:53 pm
Pinarello....ouch.
ridden an F8 and F10... not bad. But I have a BMC TImemachine Road disc which is pretty much the same... who knew :noidea:
2024 BMC TeamMachine R
2018 BMC TImeMachine Road
2002 Moots Compact-SL
2019 Parlee Z0XD - "classified"
2023 Pivot E-Vault

spartacus
Posts: 1049
Joined: Mon Apr 04, 2011 6:53 pm

by spartacus

I don't think you guys can make any serious judgements from a simplified BB deflection measurement. I asked what the numbers mean because they warrant an explanation. N/mm? Did they measure 1mm? 10mm? Is the flex really linear? How far can it flex before it stops? I don't think this is a particularly useful metric. 1mm of flex is not noticeable and something like 50-100N isn't very much force at all for a leg. Tell me how many Newtons it takes to make it flex an inch (25mm) and I might care?

tomtom
Posts: 372
Joined: Sun Oct 31, 2010 9:01 am

by tomtom

spartacus wrote:
Sat Mar 13, 2021 5:01 pm
I asked what the numbers mean because they warrant an explanation. N/mm? Did they measure 1mm? 10mm?
https://www.tour-magazin.de/service/so_ ... a1589.html
Ultimate CFR
Aeroad CFR
Grail CF

spartacus
Posts: 1049
Joined: Mon Apr 04, 2011 6:53 pm

by spartacus

tomtom wrote:
Sat Mar 13, 2021 5:46 pm
spartacus wrote:
Sat Mar 13, 2021 5:01 pm
I asked what the numbers mean because they warrant an explanation. N/mm? Did they measure 1mm? 10mm?
https://www.tour-magazin.de/service/so_ ... a1589.html
So the test assumes a linear relationship between force and deflection. Would be interesting to see a graph. 50-100N is only 10-20lb, standing and pedaling out of the saddle is probably 1000N or more so if we're talking 10-20mm deflection while sprinting I guess that's believable but it's hard to say to what extent it's noticeable when riding.

jfranci3
Posts: 1605
Joined: Tue Jul 26, 2016 5:21 pm

by jfranci3

I don't understand this chart. Just because something says "50" and it's the lowest number doesn't mean it's bad. It just might mean everything higher than 50 is excessive. You need baseline metrics on frames that are deemed "sloppy", "OK", "pretty good", "excellent" and then apply your color code. I haven't been on a bike that felt sloppy, OK, or pretty good - only excellent and you've got some of those marked in red.

Second, flex isn't a bad thing. It can become uncomforting or mechanically bad, but flex itself doesn't really cost performance. Most bikes are pretty efficent springs. Fighting flex can cost a lot more than than the flex itself by a signicant factor. Unless you're looking at a Track bike or steel/Ti bike, I'd just look at the comfort (vertical flex) and buy the lower # - OK maybe if you're buying a 61+ frame start looking at the headset stiffness.

Robius
Posts: 259
Joined: Fri Jun 19, 2015 12:35 am

by Robius

Cervelo R5 is weird with the stiffest frame and a jelly fork.
2016 Felt AR2 Di2
Retired:
2017 Giant TCR Pro 2
2015 Cannondale Synapse 6

jfranci3
Posts: 1605
Joined: Tue Jul 26, 2016 5:21 pm

by jfranci3

spartacus wrote:
Sat Mar 13, 2021 6:20 pm
tomtom wrote:
Sat Mar 13, 2021 5:46 pm
spartacus wrote:
Sat Mar 13, 2021 5:01 pm
I asked what the numbers mean because they warrant an explanation. N/mm? Did they measure 1mm? 10mm?
https://www.tour-magazin.de/service/so_ ... a1589.html
So the test assumes a linear relationship between force and deflection. Would be interesting to see a graph. 50-100N is only 10-20lb, standing and pedaling out of the saddle is probably 1000N or more so if we're talking 10-20mm deflection while sprinting I guess that's believable but it's hard to say to what extent it's noticeable when riding.


I agree, having a minimum inital force then a target force would give a better stiffness number. This is a bike you're rocking side to side, so that low to mid number is probably actually more important than the mid-force to high-force value. A low-0-low or mid-0-mid value would probably give you something more.

MikeD
Posts: 1042
Joined: Thu Dec 11, 2014 9:55 pm

by MikeD

In general, I prefer a stiff frame and fork to a flexy one, and get my comfort from wider, lower pressure tires, padded bar tape and gloves, and a comfortable saddle. In my opinion, flexy frames are more prone to shimmy, handle poorly, and waste energy by flexing instead of putting that pedaling force to the rear wheel.

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wheelsONfire
Posts: 6401
Joined: Mon Jul 07, 2014 8:15 am
Location: NorthEU

by wheelsONfire

dbzznlqbqft wrote:
Sat Mar 13, 2021 2:23 am
Recently a chart listing TOUR magazine stiffness test data caught my interest, as a guy who loves data I decided to make one for myself. All the data are from tour magazine, but as I am not a german reader there are surely some missing models & mistakes. I hope you guys can help me update it if you are willing to. Here are the models currently I am interested in, other models are also welcomed:

Factor O_2 VAM
Factor O_2
Canyon Ultimate CF EVO rimbrake version

The problems I currently noticed:
i). Comfort only stands for the stock seatpost. Some models are allowed to change the seatpost, therefore if I swap my seatpost to something like DARIMO then we might have a different result.
ii). TOUR also has the aerodynamic result on a complete bike with the stock wheelset. But as aero varies hugely between a 25mm wheel and a 65mm wheel, all I can do is to sort out these aero bikes (this might be unfair for some models such as SL7).
iii). Some framesets were tested more than one time and lead to different results. For example, theoretically, 2015 Emonda SLR10 and SLR9 use the same frame but the result varies, so what I can do is to list them both (you will see a SLR in yellow and a SLR in red).
iv). I sort the models by brand - year - frame, as I am not an expert on some brands such as SCOTT, some frame model classification might be chaotic. For clarity, I am adding "DISC" for disc brake models no matter what.

Here is the result:
Image
data312.png

I am also posting the chart that caught my interest, I referred to some data in that chart.
tour2020.jpg
Check data of the new Ax Vial EVO instead. I think it'll come out as one of the stiffest
Bikes:

Ax Lightness Vial EVO Race (2019.01.03)
Open *UP* (2016.04.14)
Paduano Racing Fidia (kind of shelved)


Ex bike; Vial EVO D, Vial EVO Ultra, Scott Foil, Paduano ti bike.

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spartacus
Posts: 1049
Joined: Mon Apr 04, 2011 6:53 pm

by spartacus

MikeD wrote:
Sat Mar 13, 2021 8:08 pm
In general, I prefer a stiff frame and fork to a flexy one, and get my comfort from wider, lower pressure tires, padded bar tape and gloves, and a comfortable saddle. In my opinion, flexy frames are more prone to shimmy, handle poorly, and waste energy by flexing instead of putting that pedaling force to the rear wheel.
The problem with this chart though is it might lead someone to believe a bike is "flexy" like the SL7 for example which certainly does not feel very flexy.

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