Brompton aluminium telescopic seat post. . . steel upper?
 

I can't seem to find an aluminium top section to the telescopic post on sale; is it just the main post that's not steel?

Top part is usually aluminum. Calhoun's in MN has a different shim in their telescoping seat post ,
steel main section, upper is 27.2 so you can use a nice integrated saddle clamp type,
though they will include a budget one.. Kalloy for either , I expect.
http://www.calhouncycle.com/productc...&idproduct=873

another shim with an ID of 1" would let one use a chromoly plain seatpost
such as sold under Red Line brand..

Might still be some Ti main section posts, around..

Looks like the official Brompton version does use a steel top post. The parts are listed here and there's no alloy version:

http://www.brompton.co.uk/technical/...egory.asp?q=F3

The top section doesn't look flared either to prevent it from being easily removed, i.e. stolen.
Given all that there doesn't seem any point in using Brompton's own brand version.

QSPTTOP is aluminum ,QSPTS , the larger bottom tube, is steel [or titanium]

with the rubber Bung in the bottom and a plug in the open upper end
of the 2 seat post parts.
a modest bit of cleverness , you can fix a piece of cable inside the seat post
anchored in the end of each.

Of course you can always just fold the bike up and bring it inside.

I think the 2011 X code light weight Brommy versions have the QSPT
A,for aluminum now
rather than Ti ... spotty sourcing, I hear.
But I don't own one. so Im not sure .

another clever option : a flat-washer that is smaller than the ID of the tube ,
but larger than the ID of the bushing at the top of the tube ,
and having that fixed in the bottom of the upper section of the combination.
will stop it from pulling out.

Ah, so the top is aluminium on the standard telescopic seatpost? Weird as it only costs £6 whereas the standard length aluminium seat post is £50.

you mean QSP6XL? its a whole post.32mm diameter, made for them .
QSPTS is mass produced. they just buy lots of them.

Aha. . . I think I'm best off sticking with my homemade telescopic seat post. Maybe. probably.

Do you know the length and OD of QSPTTOP?

No, ask : Andrew Finkill <andrew.finkill@brompton.co.uk>

Technical Support guy





Brompton Bicycle Ltd
Kew Bridge DC
Lionel Road South
Brentford
Middlesex TW8 9QR

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