Funn launch a new internally routed version of their Updown post and say they have solved the problem of seat post sag.
Back in 2016, Funn launched the external routing version of Updown dropper post that was based on an Internal floating piston (IFP) cartridge unit, similar to other cartridge based dropper posts on the market. Advantages of using IFP cartridge is lower cost and the seatpost can be serviced with ease. However, Funn says all IFP cartridges have a tendency to draw air into the hydraulic chamber over time, resulting in seatpost sag.
Funn told us "The all-new Updown adjustable seatpost utilizes a revolutionary Twin Tube Cartridge system that mechanically resets and restores oil and air locations within the cartridge whilst you use it, eradicating saddle sag issues and retaining all the benefits of a cartridge dropper post."
Here is how the Twin Tube cartridge works in more detail:
"The cartridge has an outer and inner tube that contains compress air and hydraulic oil. When the actuator is in a closed position, the seatpost is locked. At this point, the hydraulic oil contained in the inner chamber supports the rider’s weight.
When the actuator opens and dropper compresses, oil flows from the inner chamber to outer chamber, and compressed air enters the upper part of the inner chamber. At full compression, the piston respells both hydraulic oil and unwanted air from the inner tube.
When cartridge rebounds from full compression, compressed air pushes the piston shaft upwards. Only the hydraulic oil gets sucked into the inner chamber. This way the cartridge can effectively reallocate both air and oil back to its proper designated locations in the system. This ability to self-restore and refresh means less maintenance and lasting adjustability and performance."
Another feature of Updown dropper is the revised 4-way trigger lever. The new lever has a longer leverage and infinite angle adjustment. This lever can be installed with the cable head at the lever end or under the dropper. It can also be integrated with SRAM Matchmaker clamp.
- One piece forged 7050 alloy inner tube with hard anodized coating.
- 2-bolt type clamping
- 4-way mount remote lever
- Diameter: 30.9mm / 31.6mm
- Travel: 125mm / 150mm
- Weight: 550g (125mm seatpost)
- 50g lever
- The 125mm post will cost £185 and the 150mm will be £10 more
- For more details got to www.funnmtb.com
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