Introducing, the Lightworks V2 Seatpost Stopper, or more commonly known as the Brompton Lower Stop Disc (LSD).
V2 indicates this is the much improved, 2nd iteration of the Lightworks Seatpost Stopper.
An absolute must-have on all weight competitive Bromptons.
Like all Lightworks products, these Carbon seatpost stoppers are designed around weight savings, aesthetics, functionality and durability.
Just picking it up, you would feel the weight difference as the Stock LSD from Brompton is more than 3x heavier.
The Lightworks stopper is built with lightweight but oversized aluminum adjusters.
It has full adjustability down to the milimeter and has very decent stiffness.
Lightworks offers the Stopper in 6 different colours, but the anodizing is not all aesthetics. It helps to eliminate a huge rusting problem that occurs on the original steel LSD.
Lightworks uses a lightweight carbon fiber stopper which has better hardness, equating to a longer product life than the softer plastic found on the stock version.
Stock (Brompton) w Ti parts upgrade
From the Curator:
"The Lower Stop Disc (LSD) is an important and crucial component in the Brompton's folding design. It prevents the rear wheel from unfolding, when the folded bike is picked up.
Its often overlooked, but it is not a component that should be removed. The Lightworks V2 LSD offers an opportunity to shed 20 grams off the original, while preserving the Brompton's functional design and folding ingenuity."
- Ultra light weight at 8 grams
- Simple Installation (w/ the use of 1 allen key)
- Large adjustment range to fit your P/M/S/H Bromptons
- Machined ergonomics for easy adjustment by hand
- Sturdy design with 2-point contact, puts a strong hold on the seatpost.
- Available in 6 colours
- Anodized to match common components
<Tech Notes - Function>
When you pick up the folded bike, the rear wheel cannot unfold because the lower stop disc, LSD, butts against the 'folded' seat pillar, SP. The LSD can be adjusted to obtain the correct gap between itself and the SP.
<Tech Notes - Adjustment>
If the gap is too small, then the SP may foul, irritatingly, against the LSD during folding.
If the gap is too large, then the rear wheel will drop away too far when then bike is picked up, so that the hook retaining the front wheel slips off the chainstay tube (CHS) on the rear frame.