"Stack and reach" bike frame sizing...

[horsefarmer]

Always looking at bikes, never really know what i like and how a bike will fit me.
All the terminology, all the different designs, Confusing. Then I find this.
https://www.bikeradar.com/gear/article/your-top-tube-length-is-irrelevant-50174/

Lots of snow around making getting at bikes difficult, but i intend to measure a few of my favorite bikes,
and see what they measure out as.

What do you think? would be cool to have a database of some vintage bikes!

 

[MojoK]

This article caused a stir in mountain bike circles for a while. The author, long time MTB guru Lee McCormack, tries to simplify how reach and stack can be combined and used to optimize fit . His conclusions are not universally accepted, and will not bee 100% applicable to the vintage bike conversation, but it is pretty simple to understand and an interesting starting point.

https://www.pinkbike.com/news/lee-mccormacks-guide-to-perfect-bike-set-up.html

 

[MojoK]

BTW, do you actually farm horses? Just curious. Ken

 

[horsefarmer]

Oh ya, we have a few.

 

[handyandy1100]

How would ape hangers and the big back-swept cruiser handlebars figure into stack and reach? Or the curly-Q road bike bars? Is that measurement of the bar at the point it connects to the stem, or at the point where you place your hands? That would probably be pretty much the same measurement on a straight bar MTB, but way different on a pair of 16" apes.

 

[MojoK]

How would ape hangers and the big back-swept cruiser handlebars figure into stack and reach? Or the curly-Q road bike bars? Is that measurement of the bar at the point it connects to the stem, or at the point where you place your hands? That would probably be pretty much the same measurement on a straight bar MTB, but way different on a pair of 16" apes.

In the purest application, stack and reach numbers are frame measurements for comparing one frame to another.They do not take into account what sort parts you put on that frame. Once you find a riding position you love for a given style of bike, you can get reach and stack numbers for the rider.

If you love that cruiser with the 16" apes, but you know that next frame you're going to build starts with a 2" taller stack, you might go and buy a 2" shorter bar to get the same fit. The bikes we talk about on this site are much more about style and aesthetics than efficiency and fore/aft balance. Mountain bikers geek out over this sort of thing.

Here's a small taste ...1 paragraph from 1 of the 300 responses discussing "the attack position" on MTBR

"I determined what the STA should be based on placing the saddle a specific horizontal distance behind the BB (~112mm, vs ~160mm or more from others). The STA is what it is, for me, based on a rider's BB to saddle height (690mm for my 30"/76cm inseam). If I find the sweet spot angle, and offset, for a seat tube to fit multiple riders on one bike design (FS or HT), correlating to rider femur lengths, that'd be a standout discovery."

 

[handyandy1100]

In the purest application, stack and reach numbers are frame measurements for comparing one frame to another.They do not take into account what sort parts you put on that frame. Once you find a riding position you love for a given style of bike, you can get reach and stack numbers for the rider.

If you love that cruiser with the 16" apes, but you know that next frame you're going to build starts with a 2" taller stack, you might go and buy a 2" shorter bar to get the same fit. The bikes we talk about on this site are much more about style and aesthetics than efficiency and fore/aft balance. Mountain bikers geek out over this sort of thing.

Here's a small taste ...1 paragraph from 1 of the 300 responses discussing "the attack position" on MTBR

"I determined what the STA should be based on placing the saddle a specific horizontal distance behind the BB (~112mm, vs ~160mm or more from others). The STA is what it is, for me, based on a rider's BB to saddle height (690mm for my 30"/76cm inseam). If I find the sweet spot angle, and offset, for a seat tube to fit multiple riders on one bike design (FS or HT), correlating to rider femur lengths, that'd be a standout discovery."

Kind of figured as such.
At 5'-8" with a 28" inseam, I use a less sophisticated method to determine bike fit. The seat tube measurement is my most important number. If I can comfortably mount the bike, and safely straddle the top tube at a stop, everything else can be adjusted by swapping out parts.