# Is this too much seat post?



## Tarmac CK (Nov 2, 2010)

Not sure if this is the best place to post this but here goes. I am going have my bike built soon and decided to throw in my seat post to see how it would look. Now I am wondering if the recommended 54cm frame is going to be too small and would like some opinions before I go ahead with the build. 

The reason I think it might be too small is that the seat post extends from the collar 7 inches to the saddle rail. It is much more exposure than I am used to on my Cannondale synapse (56cm) alloy. I know that the tarmac sl3 pro has a sloping top tube and this accounts for some of the extra exposure. 

From bottom bracket to top of saddle my seat height is +/- 73cm and as I am switching to shorter crank arms (172.5) I am thinking my height will increase, causing even more seat post exposure. 

There is still 4 inches of post inside the seat tube so I think I am safe in that regard. I am hoping that this is okay and I am just not used to seeing so much seat post...I am 5'10" with 32" inseam. Here's a photo:


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## rcjunkie3000 (Sep 5, 2009)

Personally, I like seeing more seatpost, it makes the bike look "Pro"; looks good to me. If your seatpost is reaching that max height line then it's time to move to a larger frame. Is that a 350mm or 400mm post?


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## Tarmac CK (Nov 2, 2010)

Thanks for the response, it's a 330 mm post but it was cut about 1 inch below the minimum insertion line.


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## PJ352 (Dec 5, 2007)

I think it looks fine, but aesthetics aside, fit related issues like reach, saddle to bar drop and standover come before saddle height, which IME pretty much falls into place as long as sizing is correct. 

Once saddle height was set, as long as the minimum insertion line wasn't exposed, I'd carry on with the build. BTW, switching to shorter crank arms will _lower_ your saddle, not raise it.


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## Tarmac CK (Nov 2, 2010)

Thank you for your input, I really appreciate it.

I was thinking that shorter crank arms would mean a raise in my saddle height as the shorter length at the bottom of the pedal stroke would translate to more bend in my leg at the knee. To cancel out this additional bend, wouldn't I have to raise the seat? 

That being said, the top of my pedal stroke would then be less of an angle due to the shorter arm, which would make me think that lowering the saddle height was necessary, and now folks I have just confused myself...


Aside from that, I understand what you are saying about proper fit comes before saddle height, but judging from the height, do you think I risk building a bike that I will be unable to be fit to? I just can't really afford going through the whole process to realize that it cannot be made to work for me.


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## PJ352 (Dec 5, 2007)

Tarmac CK said:


> Thank you for your input, I really appreciate it.
> 
> I was thinking that shorter crank arms would mean a raise in my saddle height as the shorter length at the bottom of the pedal stroke would translate to more bend in my leg at the knee. To cancel out this additional bend, wouldn't I have to raise the seat?
> 
> ...


I stand corrected, You're right that shorter crank arms require a higher saddle to compensate. But it'll only change height by a couple of mm's, so I wouldn't fret over it.

Regarding the bolded statement, that's pretty near impossible to answer without seeing you, knowing how you're proportioned, your fitness level, flexibility, preferences in rider position, etc.

If you weren't sure of your sizing requirements, the LBS should have taken steps to make sure your requirements would be met with a 54cm frame prior to ordering. Get sizing wrong and you'll never have an optimal fit, and the fit parameters I mentioned previously should be what dictates that 'correct' size.


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## PlatyPius (Feb 1, 2009)

I'd buy a new seatpost. If that's a 330 and it's been cut, you risk cracking your frame. A customer of mine just went through that on his Cannondale. You need a decent amount of post in the frame. It'll add weight, but I'd go to a 400mm post.


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## tommyturbo (Jan 24, 2002)

Regarding the proper amount of seatpost "showing," part of the answer is aesthetics, but as others have posted, fit is absolutely the single most important thing that will ultimately determine how much you like your bike.

A lot of pros go with a smaller frame size to save a few grams, but mostly to increase stiffness. Yes, they have a "pro" look, but they are indeed pros. Are you a 25 year old professional cyclist built like Andy Schleck? If so, go with a smaller frame size. If not, go with the correct size for you.

FWIW, I am 5'11" and have a 32" inseam, weigh 152#, am pretty limber, and I ride a 56 S-Works Tarmac with a -6 stem that gives me around 2.25" of saddle to bar top drop. I'm guesstimating from your photo that you will have about 5"+ of bar drop with the pictured stem and spacers. Reach is another issue, and if the frame is on the small side you will have to use a longer stem, which is less than ideal from a stiffness and handling perspective.

While there is nothing inherently wrong with a lot of post showing, I would hate to see you build the bike and then have to use one of those "skyscraper" stems to get the bar high enough. I'd go back to your dealer before you cut the steer tube.


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## Hairy Legs (Sep 19, 2006)

My SP height is 82cm from center BB to top of my saddle on a 58cm frame. Your doing just fine on your SP height. Like mentioned above,i would get yourself a 400mm SP.


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## Tarmac CK (Nov 2, 2010)

@platypius Thanks, I will look into getting a longer seat post, the seat post it came with is 350mm, would that be long enough?

@tommyturbo 

Aesthetically speaking, I am not really into the tall seat post 'look.' Even if it means I could look like a pro. Just looks disproportional to me.

I am 25 (almost) but no I am not built like Andy nor am I pro. But I am coming off my first full year of racing cat5 and am looking to use this set up mainly for competition. This is probably why two different bike shop people recommended a 54 over 56, as you mentioned for the increased stiffness for racing. I can get over the aesthetics of the post but, as others have mentioned, the fit may not be ideal and I don't want to have to jury rig the bike to make it work...it needs to win races after all!

I did measure the drop and pretty sure it wasn't as high as 5 inches..Not sure if this is right but I put a level on the saddle and measured down to the top of the stem. What sort of drop am I looking for on a race oriented bike anyway? 

I will definitely go back to the shop and see what they have to say before any cuts are made.


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## PlatyPius (Feb 1, 2009)

Tarmac CK said:


> @platypius Thanks, I will look into getting a longer seat post, the seat post it came with is 350mm, would that be long enough?


For safety, I would get a post long enough that you have a full inch beyond the minimum line in the frame. So, whatever length you need to do that.


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## PJ352 (Dec 5, 2007)

Tarmac CK said:


> @platypius Thanks, I will look into getting a longer seat post, the seat post it came with is 350mm, would that be long enough?
> 
> @tommyturbo
> 
> ...


Assuming your saddle is level, place a level or straight edge (whatever is longer and gets you closer to the bars) on it (front to back) and measure from the bottom of the level to the center of the bars to get drop.

Regarding what sort of drop you're looking for, IMO the best answer to that is what feels and works best for you. To determine that, you can either experiment with different spacer/ stem angles or invest in a better than standard fitting, but first comes sizing, so determining if this 54cm frame is correct for you is step #1.


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## kbwh (May 28, 2010)

*Aestetically...*

...you're ok. Fabian's secondary bike from the 2010 P-R here:










I agree on the comments that your seat post probably is cut to short.
For anorter aestetics reference here's my 57 cm Bianchi Infinito below. It's top tube length is 56 cm (roughly equivalent to a Tarmac size 56), and it exposes appx 18.5 cm seat post.


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## wetpaint (Oct 12, 2008)

I've got 7" of seatpost showing on my Tarmac with the original post and have had no problems.

Unless you have some wierd torso length, the bike should fit you fine. I'm 5'10" with a 33" inseam and the 54 is perfect. A 56 is way too big, plus you can only get 2" of drop or so on that frame.

I think the biggest amount of drop you'll be able to get from that frame with a normal stem is 4", mine is a team Geo and it is 5" of drop with the bars on the headset.


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## roadie01 (Apr 13, 2010)

Handle bar drop from the saddle depends on your flexibility and why type of fit your looking for. 

As stated by several others on this thread get fitted! Especially before you cut the steerer or ride the bike. If the frame is too small based on your physiological needs. For example, I have a freind with a extra long torso in relation to his leg length. That combined with his lower back issues and lack of flexibility require that he ride a larger frame size to keep the handle bar drop low and maintain the reach needed. Now I'm roughly the same height as he is at 5'8" but reversed, with longer legs and a shorter torso, but much more flexible. So I ride a 54CM tarmac with about a 4" handle bar drop depending on if it's spring or fall and the length of the ride. Anything less than 100 miles I keep the drop low and tight after a couple months of training and stretching. Anything greater than 100 miles and I'll raise the stem 5mm.


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## cornas (Sep 19, 2008)

I've been on a 54' and my inseam is 83 cm and I have my sadle on something like 72.5 cm. I used a 350mm seatpost and there was plenty of seatpost left to the "min insert" mark. This year I've ordered a 52' to be able to lower my bar a bit more. So there will be even more seatpost showing...


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## AvantDale (Dec 26, 2008)

I was told that as long as the seat post is inserted past the top tube...it should be ok.


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