Brompton Seat Post Bungs

[sizbut]

New Brompton owner, loving it, might even actually ride it at some point rather than just admiring and practising fold/unfold.

But anyway, just fitted the rear rack, no problem with that. But that rack kit comes with a seat post bung and instructions to use it to replace the existing bung.

The rack kit one is a simple press fit rubber bung, the existing one is kind of expander bolt design. Whilst the Brompton instructions are clear enough, they don't say why the bung needs to be changed. Anyone know why?

[rogerzilla]

They probably just found a way to make it cheaper.

[plancashire]

Does the replacement stick out of the end of the seatpost further? If so, that is your answer. The bung also functions as a brake by pressing on the ground or floor to stop the bike rolling away on its wheels and the two little rollers on the frame or in your case on the rack end. I'm guessing that the rack end rollers make the bike slightly higher off the ground than the frame ones, so the bung/brake has to be longer to work.

[sizbut]

I think I found the reason myself today when upgrading the rack wheels to some Eazy Wheels obtained from SJS.

Each of the Eazy Wheels kits came with yet another rubber bung, so now I have 3 spares plus the one already on the bike. And the one already on the bike was just a push fit, not an expander cone as the rack instructions implied.

This time the instructions for the wheels and new bung referred to the new bung as being an expander cone type when it clearly wasn't.. And so I looked more closely at instructions and found what their date: November 2011. So it looks like whilst Brompton have changed the bungs they are fitting as standard and supplying in kits - the included instructions in the various kits are seriously lagging on being updated.

But then nobody reads the instructions... except me, and that because I write installation manuals and user guides for a living.

[gregoryoftours]

I think I found the reason myself today when upgrading the rack wheels to some Eazy Wheels obtained from SJS.

Each of the Eazy Wheels kits came with yet another rubber bung, so now I have 3 spares plus the one already on the bike. And the one already on the bike was just a push fit, not an expander cone as the rack instructions implied.

This time the instructions for the wheels and new bung referred to the new bung as being an expander cone type when it clearly wasn't.. And so I looked more closely at instructions and found what their date: November 2011. So it looks like whilst Brompton have changed the bungs they are fitting as standard and supplying in kits - the included instructions in the various kits are seriously lagging on being updated.

But then nobody reads the instructions... except me, and that because I write installation manuals and user guides for a living.

Do you work for Ikea? Instructions for Shlorpgfenk and gyontharp

[plancashire]

But then nobody reads the instructions... except me, and that because I write installation manuals and user guides for a living.

And me! And my Dad before me! As a minor part of my job I write and maintain a huge instruction manual for a complex activity and the computer system that supports it. And Jochen at our bike repair workshop reads manuals too. Just yesterday I downloaded the SRAM technical handbook to puzzle out how to fit the little red bit in the P7 gears which Hakim showed me how to fiddle into place without understanding why the fiddling worked.

If all else fails, read the instructions!