Author Topic: Replacement Brompton seat post components?  (Read 382 times)

LittleWheelsandBig

  • Whimsy Rider
Replacement Brompton seat post components?
« on: July 20, 2020, 09:06:04 pm »
While rebuilding my Brompton, it seems that I did not look very carefully at the telescopic seat post. The bottom section has a small section where the plating is lifting and corrosion is only going to progress and kill the new seat post sleeve. It used to be possible to buy individual Brompton components and there are still retailers for replacement seat post clamps and a few other bits but I can't find the bit I am looking for.

Where can I find just the lower steel tube with the flare, nothing else? It feels very wasteful to buy a new telescopic post complete with upper seat post, QR clamp and so on. I already have all of that and just need a bare steel tube.
Wheel meet again, don't know where, don't know when...

Re: Replacement Brompton seat post components?
« Reply #1 on: July 20, 2020, 10:06:46 pm »
Are Brompton posts especially prone to this? My (regular) one went the same way. I bought one of the older, heavier kind very cheap on clearance at Evans, not that that will help in your case.

LittleWheelsandBig

  • Whimsy Rider
Re: Replacement Brompton seat post components?
« Reply #2 on: July 20, 2020, 10:17:18 pm »
I guess the very long seat post may allow the post to flex enough to possibly crack the plating near the seat post clamp. Combine that with the lack of grease on a Brompton seat post and salty winter roads, then corrosion can progress under the plating.

Brompton supplied nickel-plated aluminium posts on superlight variants after they stopped production of titanium seat posts. It seemed like almost all of those Al seat posts eventually had the plating peeling off.
Wheel meet again, don't know where, don't know when...

Re: Replacement Brompton seat post components?
« Reply #3 on: July 21, 2020, 12:01:22 am »
My replacement post is certainly heavier, but doesn't really make a difference when you consider the rest of the bike. Not sure what the original was, could easily have been what you say, as the bike has Ti forks and triangle, but it was second hand on here so I did not specify the build.

Anyway, back to your search. Sorry for the diversion.

LittleWheelsandBig

  • Whimsy Rider
Re: Replacement Brompton seat post components?
« Reply #4 on: July 21, 2020, 12:04:23 am »
Converting a standard post to telescopic is possible but the telescopic post has greater wall thickness to cope with the additional leverage and (likely) rider weight.
Wheel meet again, don't know where, don't know when...

Re: Replacement Brompton seat post components?
« Reply #5 on: July 21, 2020, 08:19:18 am »
Do you need the telescopic one?  Won't the simpler, cheaper extended one do? (I appreciate the standard one is too short for most British men, and probably Australian men too)
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

LittleWheelsandBig

  • Whimsy Rider
Re: Replacement Brompton seat post components?
« Reply #6 on: July 21, 2020, 08:41:52 am »
Long legs mean the extended post is a shade short at maximum extension and the larger folded size is annoying.
Wheel meet again, don't know where, don't know when...

LittleWheelsandBig

  • Whimsy Rider
Re: Replacement Brompton seat post components?
« Reply #7 on: July 21, 2020, 12:24:51 pm »
I am thinking of trimming the bottom section by 75mm to remove the corroded section. The upper section has enough extra length to maintain the same saddle position. The bottom section can be flared to give the same function.
Wheel meet again, don't know where, don't know when...

LittleWheelsandBig

  • Whimsy Rider
Re: Replacement Brompton seat post components?
« Reply #8 on: July 25, 2020, 07:02:43 pm »
Trimming the seatpost by 75mm would still just allow locking the rear triangle when folded. 80mm probably wouldn’t.

Brompton suggested that a retailer might supply just the steel tube I am looking for but that component is not listed on Brompton’s dealer price list. I have asked Brompton which retailer might sell me just the steel tube but I am on the point of admitting defeat and purchasing a SH telescopic seat post to pinch bits from.
Wheel meet again, don't know where, don't know when...

LittleWheelsandBig

  • Whimsy Rider
Re: Replacement Brompton seat post components?
« Reply #9 on: July 29, 2020, 11:08:28 pm »
Brompton have clarified their bullshit response. They don’t supply just the lower section of a telescopic seat post but a dealer might buy a telescopic post and just sell me the lower section. Of course, they have no idea which dealer might possibly do that.

Fuck ‘em, I have bought a SH extended post for not very much and will convert it to a telescopic seat post.
Wheel meet again, don't know where, don't know when...