What is the maximum amount of seatpost one can show, according to STW law?
Bike Forum
STW seatpost law
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Posted 9 months ago #
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Up to the max mark on a 400mm post. Any more and you have the wrong size frame!
Posted 9 months ago # -
as much as you want so long as it isn't
A) carbon composite
or
B) ChromePosted 9 months ago # -
Dunno, I always need a 400mm post though, why do bike companies supply 350mm ones, they're useless!
Posted 9 months ago # -
PeterPoddy - Member
Up to the max mark on a 400mm post. Anymoreless and you have the wrong size frame!FIFY.
Posted 9 months ago # -
seatpost length = bar width/pi
Posted 9 months ago # -
doesn't matter as long as it's Thomson
but not the bent onePosted 9 months ago # -
depends on if you are going up or down.
Posted 9 months ago # -
as long as the post goes at least an inch below the bottom of the seat-tube/top-tube junction, you can have an arm length of post out the frame.
Posted 9 months ago # -
I'd say about 1/3 to 1/2 of the seat tube length.
Posted 9 months ago # -
why?
Posted 9 months ago # -
There's a complex system of rules depending on bike size, whether top tube slopes or not, type of bike etc.
I'll configure a matrix and post it up.
Posted 9 months ago # -
doesn't matter as long as it's Thomson
but not the bent one...... wassa madder with the bent one!?
Posted 9 months ago # -
Both ends of the spectrum:
Posted 9 months ago # -
...... wassa madder with the bent one!?
It's wrong, because you can do this with it.
However, fitted the right way, on certain bikes, it can look alright.
Posted 9 months ago # -
I think all really long people should have small frames with loooooads of seatpost sticking out (whilst claiming they have the correct frame size
), as they look really odd on their bikes and it amuses me. 
Posted 9 months ago # -
What about freaks like me with long legs and a relatively short body? It has to be a long seatpost on a short toptube frame. Not quite up to the maximum mark on a 410mm Thomson, though!
Posted 9 months ago # -
What about freaks like me with long legs and a relatively short body?
Larger 'women's geometry' frame?
Posted 9 months ago # -
My 250mm protruding is pretty normal then!
Posted 9 months ago # -
I like a small frame as it's "chuckable"
Posted 9 months ago # -
mine but i have a reverb now.......
Posted 9 months ago # -
do i detect mockery MrP?
normally, i'd probably agree with you, but...
i could be wrong, but i think that's a 19" cotic soul, and that's as big as they come, despite Cy being some kind of giant.
or, is it your bike? and i've got the wrong end of the stick again?
this, however, looks stunning:
(sshhh! - it's got them funny new 29" wheels...)
i think the wheel height/saddle height ratio is more critical to aesthetics than 'amount of seatpost out of frame'
Posted 9 months ago # -
Not a great picture but that's how much I run when I'm riding XC. I'm not going to lie, the frame is too small but I like it, I am half-looking out for one in L (16.5"!) though.
Posted 9 months ago # -
PeterPoddy - Member
at almost (I use flats) full leg extension I run mine above the mark by about an inch on a 410mm post. (still inserts to below the lower TT/ST weld so it's fine. and the frame fits perfecty and I run it slammed to about 4" showing most of the time.
Up to the max mark on a 400mm post. Any more and you have the wrong size frame!Mister P - Member
HTF can that Gate be considered small?I like a small frame as it's "chuckable"
Posted 9 months ago # -
What is the maximum amount of seatpost one can show, according to STW law?
4"
. How the heck I used to ride with the recommended 6" bitd I have no idea (my frames were bigger then too)
Posted 9 months ago # -
Larger 'women's geometry' frame?
I don't think so.
No, I like running a long seatpost. When I first started in this game the bike shop advised me to run the smallest frame I could get away with, and I still see no reason to question that advice.
Posted 9 months ago # -
The mark on a seatpost is to try to limit the bending moment on the seatpost, not protect the frame. They have to make an assumption on the weight of the rider and include a safety margin so you're obviously getting away with it!
Posted 9 months ago # -
small hardtail + long seatpost = more comfy that large hardtail + short seatpost ..
Posted 9 months ago # -
Surely when going downhill, having the seatpost way higher than the handlebars can't be too good for your centre of gravity?
Posted 9 months ago # -
Stw law #3
You should choose a frame that is way to small for you, ride it with a excessively long seatpost, and claim you prefer riding smaller bikes because they are more "chuckable".
Then, in true Stw style, start a thread cluelessly asking why your top tube has departed from your seat tube.
Edit: Special needs, the max height is to make sure you have enough post in the frame to stop you cracking it at the seat/top tube weld.
Posted 9 months ago # -
Edit: Special needs, the max height is to make sure you have enough post in the frame to stop you cracking it at the seat/top tube weld.
That makes an assumption about all frames having similar layout and being designed around a similar post insertion.
Surely its up to the frame manufacturer to suggest minimum insertion depth for frame integrity ,and post manufacturer for post integrity?
Posted 9 months ago # -
I managed to snap this one off last week.
There was around 25mm off post above the min. insert line in the frame.I assumed that if a seatpost was sold as 400mm length including a min insertion line that anything more than that would be fine. I am not the lightest rider though at 87kg.
Perhaps I have shouldn't have used such a lightweight seatpost but I guess I've learnt this lesson now.
Posted 9 months ago # -
That makes an assumption about all frames having similar layout and being designed around a similar post insertion.
Surely its up to the frame manufacturer to suggest minimum insertion depth for frame integrity ,and post manufacturer for post integrity?
QFT!I forget which # the stw law is that states "Flow" will usually add something retarded to most bike forum threads .
Posted 9 months ago # -
Goes off to sit on the naughty step
400mm post but a layback ..... but more than 100mm in the frame - does that make it right?
Still a bit high on this 20'' frame too I guess:
Posted 9 months ago #
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