What length have you got? Have you kept the pentaclip?

I'm looking to source a lightweight seatpost, preferably one that isn't too short, nor too long - I believe the Brompton standard length is 535mm.

update: I've just aquired my first brompton, a 2016 S2L.

would you believe it came with both the standard seat post and an extended. Good news! the standard length seems to suit me.

I thought it was too short when I tried my friends 200x P6R. Could it be brompton changed the length in recent years?


I'm 5'10" with approx. 31" inseam.

I have found seatposts (without the pentaclip fitment) in 550mm and 600mm, going to order one soon from overseas, it may take a few weeks to s
arrive so I'll see if I can get it right first time.


P.S. I'm steering away from getting a carbon post as I like the idea of titanium, I noticed that a lot of carbon seat posts tend to be 31.6" diameter instead of the brompton 31.8".

The standard Brompton seatpost is 520mm. As far as I know, it has always been like that.

But the actual seat height depend also of the saddle height and pedal thickness (+ shoes sole thickness + pant thickness).

The standard seatpost typically fits for people till 1m75-1m80 )depending of other factors including cyclist Xseam, women have typically longer legs and shorter torso than men).

There are alternative titanium seatposts in 520, 550, 580 and 600mm.

Carbon is a bad solution on a folder as it is easily scratched by dirt when folding the bike. Also carbon doesn't like many decompression/compression cycles that occur when folding/unfolding a folder.

Thanks Jipe - I've not yet concluded the mystery of the measurement that brompton refers to, the current seatpost seems to be around 550mm overall length.
I did measure approx. 520mm from the base to the underside of pentaclip, so it's more than 520 overall.

I also measured from the top face of the seat clamp to the topmost tip of the post (flush with top of pentaclip) and x = 470mm

based on this my preferred distance x is 440mm.

I guess if I order a chinese Ti seat post that's 550mm I can't be far off the mark...

It's anyone's guess have I got a 550mm or a 520mm post :-) I'm guessing it's what brompton call a 520mm.