An analysis of setback

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HammerTime2
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by HammerTime2

thisisatest wrote:
HammerTime2 wrote:Whether or not KOPS is adhered to, upper vs. lower leg length is of paramount impact to setback.

For what?
For what it winds up being (for high level) riders.

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AGW
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by AGW

Here's an updated list with saddle height and some additional riders. Some riders are duplicated with different measurements from different seasons. I think that the % provides an excellent starting point for saddle adjustment for the racing/performance-oriented rider. I'm going to measure my setback and saddle height and see how it compares. As a person with unremarkable proportions, I'm guessing it will fall close to the average % regardless of upper/lower leg lengths.
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critical measurements.JPG

thisisatest
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by thisisatest

HammerTime2 wrote:
thisisatest wrote:
HammerTime2 wrote:Whether or not KOPS is adhered to, upper vs. lower leg length is of paramount impact to setback.

For what?
For what it winds up being (for high level) riders.

I meant, the upper/lower leg ratio is of paramount impact to setback, why?
Ignoring KOPS, what does the leg ratio mean for fore-aft now? To adhere to any knee fore-aft for riders with different ratios is merely altering their weight distribution on the bike. Granted, the rider with the shorter thigh will have his hip go through a wider range of motion, but that in itself does not mandate a more forward position. Foot length and ankling would matter equally, but nobody ever considers that.
Awesome chart, btw. thanks. Now I know that if I ever have the opportunity to buy a used pro bike, it ought to be Jeremy Powers' bike!

Biff
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by Biff

Interesting.Gilbert changed saddle height from 78cm to 76cm.That´s a lot!...Setback was also changed but 2cm´s is pretty drastic..If one is to believe those numbers?

thisisatest
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by thisisatest

Could be a different saddle, one that hammocks at the point bisecting the seat tube line. fore-aft would be affected by different nose lengths too.

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AGW
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by AGW

He raised the saddle between Jan. and July 2011 when those measurements were taken. The same bike and saddle (flite) are used. He could have been refining his position or moving his cleats forward. :noidea:

Cavendish, on the other hand, is all over the place. I remember reading or hearing that he may even change his saddle height a centimeter or two between stages of a Grand Tour depending on the terrain.

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fa63
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by fa63

The numbers I have tabulated to date suggest some of the differences could be attributed to measurement error as well (different people measuring differently, etc.)

petepeterson
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by petepeterson

WW's is awesome. Unlike almost every other bike forum this one is full of actual knowledge and information! Love this stuff.

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SolidSnake03
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by SolidSnake03

Interesting to see however there could be a bunch of confounding variable here as well. I feel like cleat position. pedal type and shoe brand all can have a pretty big impact on saddle height. For example, running Bont's with Speedplays will result in a noticeable lower stack height than say Sidi's and Shimano SPD-SL's.

Regardless kind of neat to see a range of some of the heights. Turns out I fall somewhat within the range being 5' 8'' or so and having a saddle height of 72.8cm. Now bear in mind I'm riding Speedplay and Bont so super low stack height
Looks like I made a new 90 Proof friend

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AGW
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by AGW

Interesting! The only pro that rides more setback than me, as a % of my height, is Tom Boonen. :lol:

Height: 1.75m
Cycling inseam: 81.82cm
Upper leg: 58.42cm
Lower leg: 53.34cm
Saddle height from BB c-t: 73cm
Setback (SMP Evo): 9.7cm

What can I say? I guess I can't average myself to a pro without the rest of their stats. According to my chart, I'd have to move my saddle forward 2.4cm. I'd be doing pushups on my handlebars with that kind of weight distribution.

metal
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by metal

AGW wrote:Here's an updated list with saddle height and some additional riders. Some riders are duplicated with different measurements from different seasons. I think that the % provides an excellent starting point for saddle adjustment for the racing/performance-oriented rider. I'm going to measure my setback and saddle height and see how it compares. As a person with unremarkable proportions, I'm guessing it will fall close to the average % regardless of upper/lower leg lengths.


Took this saddle height and setback data and did some trig to get the average angle of virtual seat tube. I use the assumption that the middle of the seat is 15cm back from the tip (which on most seats is about where riders sit, and about where the 'center' alignment of the rails are).

The angle came out at 72.98 degrees. :thumbup:

Which is kinda interesting, as this is the angle used by many road bikes as a standard.

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djconnel
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by djconnel

AGW wrote:Here's an updated list with saddle height and some additional riders.


Can you post the data? (for example, CSV, SSV, TSV, etc)

It would be interesting to plot.

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Rick
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by Rick

I recognize and appreciate the effort in gathering such data; but it seems unusable unless correlated to some body measurement.
I don't think we can conclude anything from averages because pro cyclists are probably not average in many ways.

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AGW
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by AGW

djconnel wrote:
AGW wrote:Here's an updated list with saddle height and some additional riders.


Can you post the data? (for example, CSV, SSV, TSV, etc)

It would be interesting to plot.


I've managed to export the xls as a CSV, then I can select one or all of those upon opening. Not sure which to post.

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djconnel
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by djconnel

AGW wrote:I've managed to export the xls as a CSV, then I can select one or all of those upon opening. Not sure which to post.


Maybe a Google Doc, or just post as text here if not too long.

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