Originally Posted by
PaulRivers
I guess you don't get it, and it sounds like you haven't worked with getting a fitting right.
People like my mom who only ride sometimes shouldn't have their seat moved up and down because they won't even realize what changed. They'll just know that suddenly their bike isn't as nice to ride.
People like me who got fittings end up tweaking seat height, and there's no way I've found to mark a seat height in a way that survives lowering the seat, but the marking can be removed if you settle on a different seat height.
I've thought it was pretty cool when I see seatposts that have measurements embedded onto them, so you can just write down the measurement. But even those seem to have a reputation for the markings to wear off over time if you move your seatpost up and down much.
As far as not getting it...I used to ride as my job. I do fittings. To mark a seatpost I can put a little nail polish on the seat post, in the front where I can easily see it.
Further, I have (for my seat currently) the measurement from the top of the seat to my current pedals. If I changed pedals (different stack) I may need to recheck my seat. Same goes with shoes. You may not want to get that picky, I do because I have only ridden fitted and custom bikes since I was a kid. Not bragging, I am just using that as an indicator that allows me to set up different bikes that same way.
I own several bikes, from a couple of different manufacturers and not everything is the same. Same for my cleats. I have nine sets of bike shoes and every cleat on every shoe is exactly in the same place.
It is possible to know how to set this stuff up. And further, you should be getting a sheet with your measurements that looks similar to a geometry chart like you'd see on any bike manufacturer's site, just with your numbers.
An on my Mom's bike, I took a little nail polish and marked her seat post height as she wanted me to replace her seat. It was not a problem.
My seat needs to be 100.2cm from the pedal, max extension (crank parallel to the seat tube). That is with my current pedals and shoes (soles are the same thickness). I use the same pedals on all my bikes.
Trust me, I do fully understand this.