Seat post

[jpw]

Any thoughts on how much of a seat post should be showing above the seat tube clamp? My dealer seems fixated by the idea that one can never have too much post showing. Is this a Freudian complex?

In these times of sloping top tubes the seat post seems more and more exposed. Is there an engineering limit beyond which it just isn't safe?

[TimD]

A fist-full.

YPMV.

[Too Tall]

It depends ;)

http://www.ahealinghand.com/images/general/bikes/spectrum/heaven5.jpg

[dave1215]

tt,

you have mighty BIG fists!

[Kevan]

but it certainly is handy if there's enough post exposed that it'll fit within the jaws of your bike stand.

I think your dealer has a talent problem.

[Fixed]

bro imho it's more about what seems right to you ..i mean they have max marks on the post
cheers

[Ray]

A fist-full.

YPMV.
Grant Peterson's whole fit philosophy could be summed up by his admonitions about no more than a fist-full of seatpost showing. But that's because he really favors getting people on really big frames, getting the bars up close to seat level, etc. And because the only slope his top tubes will ever have is UP towards the bars, not down toward the seat tube. But it obviously doesn't work with slopers and it also doesn't generally work for people who like their bars a lot lower than their saddles. So, individual taste and preferences, as always, play a role.

In terms of the structural integrity of the post and seat tube, I'd tend to just work with the minimum insertion line on the post. You can push it a little bit on some frames, but that's a pretty good thing to stick to for the most part.

-Ray

[Too Tall]

Any thoughts on how much of a seat post should be showing above the seat tube clamp? My dealer seems fixated by the idea that one can never have too much post showing. Is this a Freudian complex?

In these times of sloping top tubes the seat post seems more and more exposed. Is there an engineering limit beyond which it just isn't safe?
Question. Is your shop owner Italian and was he waving a CONI manual? If the answer is yes to either, let him do his thing. Italians + bicycles is like Creme and espresso.

[jpw]

It depends ;)

http://www.ahealinghand.com/images/general/bikes/spectrum/heaven5.jpg


Is this photoshop wizardry? One can have too much of a good thing.

[regularguy412]

It depends ;)

http://www.ahealinghand.com/images/general/bikes/spectrum/heaven5.jpg

IMHO, anyone capable of actually riding that bike should be _VERY_ afraid, i.e., long legs = lotsa power = tons'o torque on that post. I wonder how much post is left _IN_ the seat tube. :D

Mike in AR

[djg]

Any thoughts on how much of a seat post should be showing above the seat tube clamp? My dealer seems fixated by the idea that one can never have too much post showing. Is this a Freudian complex?

In these times of sloping top tubes the seat post seems more and more exposed. Is there an engineering limit beyond which it just isn't safe?

Your dealer is flat wrong. If you can see the bottom of the post, you have too much seat post showing.

Heck, if you can see the insertion line, you have too much post showing.

Ya know, the aesthetic is mostly just that -- it's not that it has nothing to do with bike setup, just that it's always been a bit variable and now seems to be going just out the window with traditional, sloping, and "semi-sloping" frames all mixing it up in the market. Once upon a time -- not ancient history -- folks used to say "a fist full" (as if everybody had the same size hands). Now, it's common to look for more, and I have more on my bikes. Look at a bunch of pictures and you'll see all sorts of things. If you just have three or four centimeters of post (below the head and enough to get the saddle on), that might mean that your frame is too big or it might mean that you have short legs and certain fit issues that you didn't want to solve with a custom or made to measure frame. Or that you like it that way. If you have a foot and a half of post showing on a level top tube frame, it might mean that your frame is too small or it might just mean that you've got long legs. All of this might look more or less striking if you're 5'6" or 6'4". Personally, I'd defer to certain folks as to frame fit and bike setup questions to either solve problems I'd developed or build me a frame to fit, on which I'd be balanced. As to somebody's ideal of how much post looks good -- not so much.

[saab2000]

This is the exactly correct amount. Not more. Not less. If you look it up in the Oxford English Dictionary under "Proper Seat Post Insertion" there will be this picture with the words, " 'nuf said..... beyotch "

Anyway, don't ever go beyond the minimum insertion level. Dangerous. And at a place we don't really need danger.

IMHO, frames with sloping top tubes and a fair amount of seatpost showing need posts larger than 27.2. I saw a heavier dude on a compact Giant about 4 years ago. Poor pedal stroke and bounced a lot. And he had about 15 inches of post showing. Talk about scary flex. If that thing had snapped it would not have been pretty.

Aesthetically they can be too low. But don't go too high. If it is too high it might be a sign the frame is too small.

[Dave]

As others have noted, all posts have a minimum insertion line. If you use a 350mm post with a sloping frame, then the distance from the top of the seatpost clamp to the saddle rails could be as much 27cm or 10-5/8". Mine's only 20cm, so I'm only using 3cm of the additional length over a common 250mm post. 6cm of the exposure is due to the TT slope, so a conventional frame would have 15cm exposed.

[dirtdigger88]

while I dont have as much showing as Sir Tall- d@mn Josh!!!!

you should see my DKS in person-

a 52cm seat tube--- an 80 cm saddle height-

I picked up a Nitto post that was 46 cm!!!!!

Jason

[Too Tall]

IMHO, anyone capable of actually riding that bike should be _VERY_ afraid, i.e., long legs = lotsa power = tons'o torque on that post. I wonder how much post is left _IN_ the seat tube. :D

Mike in AR
JPW - No wizardry...well actually lots of masterful genius...actually :)
Mike - There is approx 400 mm of post. This is a super nice one off from Albert Bold. He rolled a larger dia. Ti tube down to gain extra wall thickness and than hydraformed it...or at least to the best of my knowledge and it does not budge AND there is more than enough post in the frame...trust me. Tom Kellogg does not design anything less than perfection :) Woo Hoo.

PS - I am a weak and frail old man. What is torque and power? I used to know a guy.... ;)

[musgravecycles]

To the op, this looks to be about right to my eye ;) :

http://i192.photobucket.com/albums/z311/jhcakilmer/4-1.jpg?t=1194624036

[Ken Robb]

Am I correct in guessing that the minimum line post makers add to their products reflectwhat they think is required to prevent the post from failing? If that is so does it vary with different lengths of the same model of post? In other words is the minimum insertion line the same on a 350mm Thomson Elite the same as on a 250mm? Would the longer post at minimum insertion allow too much leverage to be applied to the seat tube and collar causing damage and danger of failure to those parts?

My bikes are all fistful setups except my mtn. bike and it is a fat post and tube so my interest is purely academic.

[DarrenCT]

i kinda like this setup.

http://img221.imageshack.us/img221/7964/bikerideredding001st4.jpg (http://imageshack.us)

[DarrenCT]

that zero is simply beautiful. id be all over that bike. cheers
-d

[Too Tall]

You heard em' boyee. Get your act together OK?

[Samster]

that zero is simply beautiful. id be all over that bike. cheers
-dthe atmo is not half-bad either imo.

[OldDog]

http://forums.thepaceline.net/showthread.php?t=24518&highlight=derosa

[regularguy412]

JPW - No wizardry...well actually lots of masterful genius...actually :)
Mike - There is approx 400 mm of post. This is a super nice one off from Albert Bold. He rolled a larger dia. Ti tube down to gain extra wall thickness and than hydraformed it...or at least to the best of my knowledge and it does not budge AND there is more than enough post in the frame...trust me. Tom Kellogg does not design anything less than perfection :) Woo Hoo.

PS - I am a weak and frail old man. What is torque and power? I used to know a guy.... ;)

ROFL :)

I was pretty sure that was your bike,,that's why I put the smiley face on there. Just pullin' your chain, Big Guy.

I'm not worried 'bout ya. I knew you had it under control.

:beer:
Mike in AR

[Peter P.]

How much seatpost is exposed is relative to the frame size you choose.

Of course, when you chose your frame size you considered top tube length as well, right?

All this is with regard to horizontal top tubes; with compact frames, it all goes out the window.

By selecting the proper frame size, you can straddle the top tube in a panic stop without whacking your private parts on the top tube, yet raise the seat high enough for proper leg extension.

The proper frame size will also let you raise the bars to a comfortable height.

Generally speaking, smaller riders cannot tolerate as great a discrepancy between the seat height and the handlebar height, so smaller riders should have proportionately LESS seatpost showing on their frames than taller riders.

Greg LeMond had a very good rule of thumb for checking to see if your frame size was about right, but don't neglect a proper fitting top tube length. His rule was if your frame size was chosen properly, then when the seat height was set correctly, the amount of exposed post was about equal to the length of the head tube.

I think this works well aesthetically as well as fit-wise, enabling you to get the bars high enough and still be a good position for racing. I don't feel today's compact frames permit this.

I find when using the 2/3 of inseam rule to choose a frame size, it tends to result in slightly more exposed post than LeMond's rule recommends.

For good photos of seatpost exposure, check Richard Sach's website.

http://richardsachs.com/rsachs2.html

The two road bikes on the left are good illustrations of a proportional amount of post on a horizontal tubed frame and notice both frames are different sizes, and the resultant reasonable handlebar height.

[Grant McLean]

Generally speaking, smaller riders cannot tolerate as great a discrepancy between the seat height and the handlebar height, so smaller riders should have proportionately LESS seatpost showing on their frames than taller riders.

Greg LeMond had a very good rule of thumb for checking to see if your frame size was about right, but don't neglect a proper fitting top tube length. His rule was if your frame size was chosen properly, then when the seat height was set correctly, the amount of exposed post was about equal to the length of the head tube.

+1

small frames look much better with less post, atmo.

-g

[musgravecycles]

+2

Exposed seatpost is proportional to frame size. Generally the post=HT rule is pretty close to my eye.

Thanks Darren, judging by the pics she's prolly a little large for you though...
:banana:

[dirtdigger88]

17 cm head tube

19 cm post

http://i96.photobucket.com/albums/l162/dirt_011/pauls001.jpg

Jason

[Jeff Weir]

Darren,
It does appear that the frame is to big for you. It's time to blow that baby out on ebay and get one that fits properly.

Good luck with the sale

[DarrenCT]

Darren,
It does appear that the frame is to big for you. It's time to blow that baby out on ebay and get one that fits properly.

Good luck with the sale

wahaha!

this frame actually has a 56 tt. my new kirk will have a 57 tt. the sachs will never be on ebay.

too bad suckahs

:)

[vaxn8r]

Two variables you gotta know.

Sloper or Horizontal?

Modern seat or classic? Those older Selle Italia Turbos or San Marco Concors and Rolls for example, covered more of the post. The newer style Toupe, Selle Italia SLR, Fizik etc show the entire post clamp.

[stevep]

never mind tts mt bike...his drop is proportional and not that deep.

check out a pic of ryan treborns cross bike if you wanna see a bike that is hard to believe that anyone could actually ride.

[Jeff N.]

Level top tube: About a fist or a little more.
Slpoer: Whatever's necessary. Jeff N.

[coylifut]

Am I correct in guessing that the minimum line post makers add to their products reflectwhat they think is required to prevent the post from failing? If that is so does it vary with different lengths of the same model of post? In other words is the minimum insertion line the same on a 350mm Thomson Elite the same as on a 250mm? Would the longer post at minimum insertion allow too much leverage to be applied to the seat tube and collar causing damage and danger of failure to those parts?

My bikes are all fistful setups except my mtn. bike and it is a fat post and tube so my interest is purely academic.

your logic is correct. a 350 post will have more material below the line than a 280 post with every mfg i've seen.

separately, i've seen a few frame failures where the post didn't insert far enough past the seat tube/top tube junction. not frequent, but enough to mindful of it.

[Grant McLean]

Modern seat or classic? Those older Selle Italia Turbos or San Marco Concors and Rolls for example, covered more of the post. The newer style Toupe, Selle Italia SLR, Fizik etc show the entire post clamp.

+1

Also, a classic saddle like a Turbo or a Rolls is taller above the rails.
Change from a Regal to a flight, and you need to raise the post at least 1cm.

-g

[jerk]

who cares how the bikes looks? how about how does the rider look on the bike?

jerk

[Big Dan]

Different pedals may cause you to raise or lower your saddle also.....

:p

[Grant McLean]

who cares how the bikes looks? how about how does the rider look on the bike?

jerk


we are not worthy of your insight !!

-g

[don'TreadOnMe]

ot:
anyone know a video/dvd of a fine bartoli race?

[Big Dan]

96 Flanders is pretty good. imho.

:beer:

[Too Tall]

(sigh) So I'm on the team ride this morning...it's a Belgian kinda thaing...cold mist, wet roads...pissin' and moaning....I'm coming up the right and the second tallest guy on my team says "no wonder I can't buy a long seatpost Josh cornered the market" and I was lookin' all eruopimpdaddycool and stuff too...sheesh! Seatposts. You need them.

[coylifut]

who cares how the bikes looks? how about how does the rider look on the bike?

jerk

absolutely no one looks better.

the 2001 Het Volk is a good one.