# What size Brompton seat posts are you guys using?



## chris folder (29 Feb 2016)

HiI have always used the standard seat post on my brompton I'm 5 8 I have the penta clip flipped up yet I still feel like the seat could be little higher 1/4" more would be perfect I have purchased the longer seat post I'm fitting it tomorrow. I looked at the telescopic post but did not want the extra weight only draw back with one i got it will not push fully into frame when folded. Brompton say standard seat post is ok up to 5 10 im not sure dont seem high enough and thats with out flicking penta clip. What seat post you guys useing?


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## scalyman (29 Feb 2016)

Standard size 535mm Titanium off Ebay not at full extension (about 1.5" to go) and I'm 5' 10"


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## alicat (29 Feb 2016)

Standard one.

I'm a girl, mind.

And 5'5".


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## Brommyboy (29 Feb 2016)

Standard post with pentaclip almost at the top; height 5'7". Saddle could be higher but I like to be able to put one foot on the ground when stationary! Maybe your legs are longer!


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## chris folder (29 Feb 2016)

Hi yep your right my inside leg length suits the longer post measurements im going to swap post over Tuesday now im out on a ride I will test new post then I only want 1/4 more hight but that can make big difference


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## Kell (1 Mar 2016)

I've got the extended one and I'm just under 6'.

Interestingly, the Brompton I hired had the telescopic one and even with the top bit not slid right down, it still was lower than the extended one when fully folded.

I know this as my Brompton goes in the boot of my Mini convertible (just) and it fitted in more easily with the telescopic post.

In the end, I reduced the rubber bung in the bottom of the post to give me a little more wiggle room. I basically just cut it in half so the seat would drop a tiny bit lower.

Also having the telescopic post meant the seat height was correct every time without having to go through the process of setting up the little plastic bit that slots in the seat tube.


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## shouldbeinbed (1 Mar 2016)

Standard at full extension and pentaclip set high. I'm 5'11"


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## CopperBrompton (1 Mar 2016)

I'm 5'9" and the standard post at maximum extension is perfect for me.


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## Fab Foodie (1 Mar 2016)

5'9" but a tad short in the leg .... Standard post fully extended, pentaclip highest position and a B17.
I have recently added a rearward extension.


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## Fab Foodie (1 Mar 2016)

User said:


> Or saddle pack as the rest of us call it.


No, a rearward extension. It allows the saddle to be set either fore or aft of the seat post. In my case it moves the saddle back. 

Apols for the poor photo but ....


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## StuartG (2 Mar 2016)

shouldbeinbed said:


> Standard at full extension and pentaclip set high. I'm 5'11"


Me too on standard post and Brooks B-17. Except I'm a few inches shorter but have 32" inside leg which is probably the relevant measure rather than plain height. (short/long upper bodies v long/short legs).


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## cosmicbike (2 Mar 2016)

Extended post for me, 5'11". Standard was just that bit too short.


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## e-rider (11 Jan 2017)

I'm 6'1.5" and have been thinking about Brompton seatposts - I read that some people at my height seem happy on an extended, whilst others say I would need the telescopic??? Obviously the telescopic would do the job but the extended looks better and simpler


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## jay clock (11 Jan 2017)

Trikeman said:


> I'm 5'9" and the standard post at maximum extension is perfect for me.


same for me. I am lucky in that respect


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## mustang1 (11 Jan 2017)

6'1: the long one but not telescopic.


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## cheys03 (12 Jan 2017)

For 1/4", approx 6-7mm you might find a saddle with rails/cushion height that give you the extra.
Advantage being you'd have the post set the the right height every time just by pulling out to max.


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## chriscross1966 (12 Jan 2017)

5'9, a Carbon fibre one cut to be halfway between the standard and the long one.


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## Kell (12 Jan 2017)

I hired a Brompton with the telescopic and thought it was brilliant. 

I ended up buying one with the extended post as i didn't need the full extension of the telescopic one but it does become surprisingly useful. 

Because it consists of essentially two seat posts, you can set the one that actually goes in the bike at full extension. Then use the smaller one to set the seat height correctly for you.

Then you leave that one alone. 

When folding/unfolding the bike this means the seat is always at the correct height when you get on. 

I know they now have a plastic shim that means you can do this too, but that's a faff to set up IMO. 

It also means that the bike folds up ever so slightly smaller. 

I put my Brompton in the back of our convertible Mini daily and the hired one with the telescopic post fitted in better than the one I bought with the extended post. It's not a huge problem, but I think I would get the telescopic one if buying again - just for ease of use. 

I'm just over 5' 11" btw.


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## 12boy (12 Jan 2017)

I too am a towering 5'8''. I go with 34.5 inches from pedal surface to seat top and have at least an inch of seat post left unused. In pictures of Bromptons it seems the seat is as far forward as possible.Does anyone have insight into the ergonomics of having the seat forward or back? I have S bars and like mine about medium but I am just guessing as to what is most efficient.


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## Oxo (12 Jan 2017)

I have a standard post. Setting up the plastic shim was really simple and only took a few minutes.


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## reppans (12 Jan 2017)

I'm using Gorilla tape for my seat height shim - free and you don't even need to remove the seat. Gorilla tape glue also seems much more resistant to becoming cement residue, like duct tape, when you want to remove it. 

Forward/back seat alignment should be set using the knee-plumb-line-to-crank method, but some might shift that bit forward for a smaller fold.


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## e-rider (13 Jan 2017)

mustang1 said:


> 6'1: the long one but not telescopic.


so give or take 1cm you are my height - I have average length legs for my height. Would you say that you have enough length in the extended post or are you riding with it at the max? Brompton say up to 6'2" for the extended but many people that height claim it's not long enough

How much bend is in your knees?


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## CopperBrompton (13 Jan 2017)

12boy said:


> Does anyone have insight into the ergonomics of having the seat forward or back? I have S bars and like mine about medium but I am just guessing as to what is most efficient.


I find it doesn't make a huge difference. Mine was fully-forward when I got it, and I've recently had to set it fully-back to accommodate a seat-rail GoPro mount. The new riding position is marginally sportier, but felt completely normal within a matter of minutes.


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## Kell (13 Jan 2017)

My biggest bugbear with Brommies is that they're so short.

I put my seat as far back as it would go and even flipped the pentaclip as it gives a little bit extra.


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## 12boy (14 Jan 2017)

You might try an Aber Hallo which allows you to extend your reach with the handlebars a couple of inches.Use one with a QR on the handle post and you can rotate to avoid folding problems.


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## Kell (14 Jan 2017)

Cheers, mine feels fine now. I use quite long bar ends too.


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## velovoice (14 Jan 2017)

Fab Foodie said:


> No, a rearward extension. It allows the saddle to be set either fore or aft of the seat post. In my case it moves the saddle back.
> 
> Apols for the poor photo but ....
> 
> View attachment 120574


Where can I get one of those, please? And do they come in different diameters? I really need something like this for my two vintage bikes (with straight posts - I've forgotten the diameter but can find it) with very slack seat tube angles. My knees would be really grateful!

Sorry for thread hijack.


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## velovoice (14 Jan 2017)

12boy said:


> Does anyone have insight into the ergonomics of having the seat forward or back?


This is a matter of bike fit, determined by a number of factors (_*none of which are reach to the handlebars*_) including the length of your feet and proportions of your legs, in particular the length of your femur. The fore/aft position of your saddle will determine the relative position of your hips to your pedal spindle, and from there all the angles of your legs (bent at ankle, knee and hip, each angle working as levers).

This is of course very simplified. If you have serious concerns about your set up, get a bike fit (by a trained professional) or an assessment by a physiotherapist who specialises in cycling.

ETA: Oops, thread hijack again! Seems endemic on this thread...


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## Pottsy (14 Jan 2017)

5'9" height / 29.5" inside leg / standard seat post just under maximum height.

I use one of those clever plastic inserts which restricts the height to the exact level I need it (so I just lift it too full extension).


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## GrumpyGregry (14 Jan 2017)

six two and telescopic for me. standard is an annoying smidge too short.


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## Fab Foodie (14 Jan 2017)

velovoice said:


> Where can I get one of those, please? And do they come in different diameters? I really need something like this for my two vintage bikes (with straight posts - I've forgotten the diameter but can find it) with very slack seat tube angles. My knees would be really grateful!
> 
> Sorry for thread hijack.


Hi Rebecca, here!
https://www.sjscycles.co.uk/seat-posts/brompton-saddle-adaptor-pin-assembly/?geoc=US

I have one on my B. to set the seat further behind the seatpost. Works a treat :-)


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## e-rider (14 Jan 2017)

GrumpyGregry said:


> six two and telescopic for me. standard is an annoying smidge too short.


did you ever try the 'extended' post?


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## GrumpyGregry (15 Jan 2017)

e-rider said:


> did you ever try the 'extended' post?


Sticks up too far when you fold.


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## Kell (16 Jan 2017)

12boy said:


> I too am a towering 5'8''. I go with 34.5 inches from pedal surface to seat top and have at least an inch of seat post left unused. In pictures of Bromptons it seems the seat is as far forward as possible.Does anyone have insight into the ergonomics of having the seat forward or back? I have S bars and like mine about medium but I am just guessing as to what is most efficient.



I did worry a bit about having my seat too far back as I thought Brompton might set them up that way so that your weight pushes straight down the seat tube rather than trying to force it into an arc. But having seen Fab Foodie's backwards extension, I think I'm probably safe.


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## Dogtrousers (16 Jan 2017)

6'3" Telescopic.

Edit: That is to say, I'm 6'3" tall and I use a telescopic seat post. Not that I use a 6'3" telescopic seat post. That would be quite unusual.


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## 12boy (17 Jan 2017)

After reading the above and noticing I have maybe an inch of post in the bike yet, with my Pentaclip at the top of the post but turned so the rail rides low, I measured my post. It is 23.5 inches (600mm) and means I must have the long seat post. Since the long post is 80 mm longer than the short that is probably good since without it I'd probably lack 1/2 and inch or so of my ideal pedal to saddle distance. Chris folder is right, though. If I move my saddle up or down even an 1/8 of an inch it is noticeable and does not feel right.


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## chriscross1966 (17 Jan 2017)

Dogtrousers said:


> 6'3" Telescopic.
> 
> Edit: That is to say, I'm 6'3" tall and I use a telescopic seat post. Not that I use a 6'3" telescopic seat post. That would be quite unusual.



Yes.... we suffer enough from the "Clown BIke" comments as it is


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## doginabag (18 Jan 2017)

I'm 5'9" with an inside leg of ~30".
I have the standard seat post which I found a little short on full extension. Turning the pentaclip over gave me about another inch in height and I have the saddle almost all the way to the real. 

Sometimes I feel like I could still do with one more inch (yes, still talking about the seat post!) but I do tend to like a bike set up so that my legs get almost straight all full stroke.


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