# How to measure a seat post



## Ty (May 20, 2004)

Hi Bike Bulimics,

what is the way to determine the length of a seat post ?

Is is from the centre of the saddle rails to the bottom of the seat post ?


Also how much (or how little) seat post is it wise to leave in the frame

If it makes any difference it will be a USE Carbon post in a Klein Adroit (hardtail) frame (31.6mm)

cheers for any info


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## nino (Jan 13, 2004)

*correct...*



•Ty• said:


> Hi Bike Bulimics,
> 
> what is the way to determine the length of a seat post ?
> 
> ...


lenght of a seatpost is measured from the bottom of the tube to the middle of the seatrails.

you usually should have about 2.5-3 times the width of the seatpost diameter inserted:
on a 31.6mm post that's ca. 75mm minimum.


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## Max (Jan 13, 2004)

seat post adapters should at least measure 3 inches (75 mm), as Nino said. Carbon seat posts should preferably be used with an adapter. 

depending on your seatpost length, some frame builders also say it's enough to insert the post right beneath the tub tube. anyway, the longer the better


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## carlos (Jan 12, 2004)

*just to make sure..*

thomson advices to leave at least 10cm of seatpost inside your frame.


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## Boj (Jan 13, 2004)

?Ty? said:


> Hi Bike Bulimics,
> 
> what is the way to determine the length of a seat post ?
> 
> ...


Dude, what brakes are those? They look light.


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## Ty (May 20, 2004)

Max said:


> seat post adapters should at least measure 3 inches (75 mm), as Nino said. Carbon seat posts should preferably be used with an adapter.
> 
> depending on your seatpost length, some frame builders also say it's enough to insert the post right beneath the tub tube. anyway, the longer the better


My frame takes a 31.6mm post diameter (Klein)

USE make a carbon USE Alien in 350mm / 31.6mm so I was hoping to use this
(they do not make a 400mm in carbon  )

That would mean I would use it *without* a shim (adapter), is this ok?

I would have 85mm inside the frame, from the *top* of the seat clamp to the base of the seat post, with only 20mm below the base of the top tube.

I only ride this bike on the road (no off road stuff, just the occasional bunny hop over a pot hole in the road), also I am not a big heavy fella'.

Do you think I will be ok with the USE Carbon post or should I go for a the USE Aluminium (400mm / 31.6mm) ?

I would prefer the Carbon!

Cheers for all your input

Ty


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## Ty (May 20, 2004)

My frame takes a 31.6mm post diameter (Klein)

USE make a carbon USE Alien in 350mm / 31.6mm so I was hoping to use this
(they do not make a 400mm in carbon  )

That would mean I would use it *without* a shim (adapter), is this ok?

I would have 85mm inside the frame, from the *top* of the seat clamp to the base of the seat post, with only 20mm below the base of the top tube.

I only ride this bike on the road (no off road stuff, just the occasional bunny hop over a pot hole in the road), also I am not a big heavy fella'.

Do you think I will be ok with the USE Carbon post or should I go for a the USE Aluminium (400mm / 31.6mm) ?

I would prefer the Carbon!

Cheers for all your input

Ty


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## carlos (Jan 12, 2004)

remember USE advice you should use the shim with the carbon post, so, you should get a smaller size and use the shim to 31.6. anyway, i would get the aluminum version.


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## Ty (May 20, 2004)

carlos said:


> remember USE advice you should use the shim with the carbon post, so, you should get a smaller size and use the shim to 31.6. anyway, i would get the aluminum version.


Thanks Carlos, yeah I was thinking about this too but I read this.

This is a quote from www.leisurelakesbikes.com.

_The natural carbon weave tube provides incredible strength. USE don't comprimise to save small amounts of weight. This seatpost has the right strength, safety, durability and security to rid all those fears which you have had about carbon posts. The 7075 forged Alien clamp is forged for strength and CNC machined for tolerance. MTB extra thick wall for direct fit without shim._

what do you think ? to shim or not to shim ??????


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## carlos (Jan 12, 2004)

i would use the shim but to make sure email USE.


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## nino (Jan 13, 2004)

*you're ok...*



�Ty� said:


> My frame takes a 31.6mm post diameter (Klein)
> 
> USE make a carbon USE Alien in 350mm / 31.6mm so I was hoping to use this
> (they do not make a 400mm in carbon  )
> ...


that's more than enough post inserted. newer USE carbon posts don't need a shim anymore. they are reinforced (and are therefore slightly heavier). the actual 31.6/350 weighs 200g.
what's the best offer you found for that USE carbon?


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## carlos (Jan 12, 2004)

i think the extralite "standard" will be a much better option.


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