Stack and Reach question

Discuss light weight issues concerning road bikes & parts.
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Lookryder
Posts: 27
Joined: Sun Aug 06, 2017 12:37 am

by Lookryder

I'm trying to determine the stack and reach of my current frame, a 2008 Look 586 size XL.

can anyone help me?

I think I calculated the reach at 408 mm , but this seems too long.

The geometry chart does not have it listed:

Image

Alexandrumarian
Posts: 200
Joined: Mon Mar 28, 2016 6:34 pm
Location: Romania

by Alexandrumarian

Sounds right, b-e. Seems normal for an xl. Giant tcr xl is 412.

by Weenie


Lookryder
Posts: 27
Joined: Sun Aug 06, 2017 12:37 am

by Lookryder

how about the stack?

FilmAt11
Posts: 288
Joined: Sun Jan 09, 2011 2:35 am

by FilmAt11

Based on that chart, I calculated:

stack: 580mm
reach: 398mm

Lookryder
Posts: 27
Joined: Sun Aug 06, 2017 12:37 am

by Lookryder

Thank you so much!! I knew I was off a bit.

mike001100
Posts: 99
Joined: Sun Dec 04, 2016 10:26 am

by mike001100

Hiya, I wholeheartedly recommend the Velogic Fit app... registration is free and the "bike comparison tool" is also free... it is very helpful when comparing bikes, as the database seems to be quite up to date...

I put in your Look, the app says: Reach 398, Stack 581

All other measurements are there too...

wingguy
Posts: 4193
Joined: Thu Mar 08, 2012 11:43 pm

by wingguy

Lookryder wrote:Thank you so much!! I knew I was off a bit.

You know it's very easy to physically measure it as well, right? All you need is a flat floor, vertical wall and a tape measure...

Lookryder
Posts: 27
Joined: Sun Aug 06, 2017 12:37 am

by Lookryder

wingguy wrote:
Lookryder wrote:Thank you so much!! I knew I was off a bit.

You know it's very easy to physically measure it as well, right? All you need is a flat floor, vertical wall and a tape measure...


I know. I did meausre it myself several times and the repeatability of the measurements was not good enough for me; it would vary by a few mm every time. I wanted to know what was listed on the the geo chart as I'm trying to find a frame of similar stack and reach. The more data the better.

Valbrona
Posts: 1504
Joined: Fri Oct 28, 2011 3:25 am
Location: United Kingdom of Great Britain and Northern Ireland

by Valbrona

But in the above chart doesn't B' show reach?

TobinHatesYou
Posts: 1773
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

Valbrona wrote:But in the above chart doesn't B' show reach?


B' is actual top tube length. Frame reach is B minus E.

cyclenutnz
Posts: 772
Joined: Tue Jul 18, 2006 5:18 am
Location: Cambridge, New Zealand
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by cyclenutnz

mike001100 wrote:Hiya, I wholeheartedly recommend the Velogic Fit app... registration is free and the "bike comparison tool" is also free... it is very helpful when comparing bikes, as the database seems to be quite up to date...


Just a note on using the database - if you scroll to the bottom of the frame specifications you'll see the 'Calculated Measures' field. Which tells you which metrics I've had to calculate.
In the case of the 586 - that's wheelbase, reach and stack. I have a very robust algorithm for doing that and Look provide really good information on other measures, so there is pretty high confidence. But there is a little more uncertainty than if the manufacturer had provided the XY data.

Having said that, I frequently find errors in the geometry charts of large companies that make a lot of noise about bike fit. So the overall standard of the database is more reliable than other sources.
http://www.speedtheory.co.nz
http://www.velogicfit.com - 3D Motion Capture and Frame Finder Software

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silvalis
Posts: 469
Joined: Mon Sep 07, 2015 1:02 am
Location: Aus

by silvalis

TobinHatesYou wrote:
Valbrona wrote:But in the above chart doesn't B' show reach?


B' is actual top tube length. Frame reach is B minus E.


Keep in mind that if you measure reach doing this, the geo chart indicates that it is measured to the centre/centre intersection of the top tube/head tube junction. Typically reach/stack is measured to the centre of the top of the headtube.

So to compare to others measured as above, you'd need to also look at the headtube measurements (K, KO), read the ht angle, do a bit of trig and subtract a few mm...
Chasse patate

by Weenie


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