Originally Posted by
Kapusta
Frame stack is NOT another way of saying standover. They are two completely different measurements. All they have in common is they are vertical.
Definition of frame stack:
Stack The vertical distance from the centre of the bottom bracket to the central point at the top of the head tube.
Add the bottom bracket height and you have standover. Same measurement. From the same place.
Originally Posted by
Kapusta
Standover matters when you are standing over the bike. Stack matters while you are riding the bike.
Standover matters when you have to get on the bike. Stack may matter while riding but if you can comfortably get on or off the bike, it won’t matter if the stack is perfect.
Originally Posted by
Kapusta
Two frames can have the same standover with drastically different stack heights, and vice-versa.
Only if the bottom bracket height is different.
Originally Posted by
Kapusta
I got an in depth professional Serrota fit a few years back. I came away with a data sheet showing the optimal frame size. It gave a lot of info in terms of bar width, saddle angle, height and setback from BB, distance and drop from saddle to hoods, cleat placement, crank length. It also gave optimum stack and reach as measured to the base of the stem.
You know what is NOT anywhere on the spreadsheet? Standover height.
That’s because everyone seems think it doesn’t matter. Tell that to small people who are put on bikes that are too big for them because no one makes bikes the right size for them. For years, my 5’ tall wife had to endure bikes that were 3” to 5” too tall. Try riding when you can only straddle a bike on your tiptoes and then tell me that standover doesn’t matter.
Originally Posted by
Kapusta
And when I worked with the shop to find frames to fit me, their primary criteria was looking at the stack and reach. They also took into account head angle for frames that would require much in the way of spacers, as that affects the reach. Everything else (including standover) just needed to be “good enough”. And the reality was that any size from one or two larger all the way down to the smallest they offer would have been fine for standover. Of course there were other “critical” numbers (like bb height, CS length) but those are primarily handling related, not fit related.
I’ve bought many, many bikes. I have never...not once...had someone ask me about stack or even reach. I’ve been in a lot of shops and seen people”fitting” bikes and not a single one has every been asked about frame stack. Going back to bikes for small people, especially for mountain bikes but also small framed road bikes with 700C wheels, the top tubes are often too high where the small rider has to stand. Shocks push the front higher and leave even less room. We “normal” sized people don’t have to deal with that. But it is critical for lots of others.
Originally Posted by
Kapusta
If you think standover height is a good way to size a bike, fo for it, but I doubt you will find many fitting pros who would agree it is as good a method as stack and reach.
Standover is a place to start. It’s the easiest way to screen a lot of bikes. Bikes are more about how they feel than a list of numbers.