Thomson Dropper Post - Eurobike 2012
• Telescoping seat post
• 5''/127mm drop (internally adj. to 4'')
• Infinitely adjustable travel
• Hydraulic internals
• Nitrogen return spring (not adjustable)
• Lever-adjustable return speed
• Weight: 450g (prototype)
• Availability: March/April 2013
• Projected MSRP $380
Thomson stirred up a hornet's nest of activity when they teased riders with a few quick photos of their upcoming telescoping seat post on their Facebook page a few months back, but no other information was available at the time. Fast forward to Eurobike and they were showing off the new post, dubbed the 'Elite Dropper', in their booth, which we made our first stop of the show. The post is still in the early prototyping stage, with only a few functioning samples in the wild at this point.
The Elite Dropper offers 5"/127mm of infinitely adjustable travel, meaning that it can be positioned anywhere between and full extension fully lowered . The travel is controlled with a sealed cartridge (it can be worked on by a service center, though) that separates the post's hydraulic oil from the non-adjustable nitrogen return spring that is set at 135psi. Thomson has employed a clever second check valve within the cartridge that keeps the post from pulling up through its travel when lifting the bike by the saddle, thereby remedying a somewhat annoying trait of some other hydraulically controlled posts.
While it looks as if Thomson has refined existing dropper post technology rather than reinventing it, they have done something completely different to eliminate any side to side saddle wiggle from the Elite Dropper. Rather than use multiple keyways to keep the round stanchion from rotating, an interesting sixteen-point shaft - that fits within a matching sixteen-point profile within the outer tube - is attached to the bottom of the stanchion. This requires assembly to involve sliding in the stanchion from above, then threading the sixteen-
The Elite Dropper offers 5"/127mm of infinitely adjustable travel, meaning that it can be positioned anywhere between and full extension fully lowered . The travel is controlled with a sealed cartridge (it can be worked on by a service center, though) that separates the post's hydraulic oil from the non-adjustable nitrogen return spring that is set at 135psi. Thomson has employed a clever second check valve within the cartridge that keeps the post from pulling up through its travel when lifting the bike by the saddle, thereby remedying a somewhat annoying trait of some other hydraulically controlled posts.
While it looks as if Thomson has refined existing dropper post technology rather than reinventing it, they have done something completely different to eliminate any side to side saddle wiggle from the Elite Dropper. Rather than use multiple keyways to keep the round stanchion from rotating, an interesting sixteen-point shaft - that fits within a matching sixteen-point profile within the outer tube - is attached to the bottom of the stanchion. This requires assembly to involve sliding in the stanchion from above, then threading the sixteen-
point section into place through the bottom of the outer tube, followed by screwing the silver bottom cap onto the bottom. This layout allows Thomson to utilize traditional round bushings from Norglide to keep the post's travel smooth, although the upper, stationary bushing sports a custom finish to further enhance the post's movement.
Thomson is being very clear about one thing: reliability is the focus of the new dropper post. They are aiming to have the Elite Dropper trump everything else on the market when it comes to longevity, a goal that will likely make the Thomson post a favorite among riders if fulfilled given how unreliable most current designs are.
Thomson is being very clear about one thing: reliability is the focus of the new dropper post. They are aiming to have the Elite Dropper trump everything else on the market when it comes to longevity, a goal that will likely make the Thomson post a favorite among riders if fulfilled given how unreliable most current designs are.
Head-mounted actuation The Elite Dropper's actuation arm is located on the side of its two-bolt head (that features the very same rail clamp as used on their standard seat posts), with a bolt-on cable stop and arm that is pulled on by a standard shift cable. Hidden from view within the post's head, the actuation arm pushes down on a plunger located at the top of the cartridge, thereby opening the oil port and allowing the post to stroke through its travel. Interestingly, Thomson allows riders to choose from varying rebound speeds despite its shift cable actuation thanks to a cam design on the plunger that determines the amount of oil flow allowed when engaged - pushing the lever completely through its travel will result in a faster return speed than if the rider only depresses it partway. While we didn't get to try the system on a bike, it should allow riders to easily find those partially dropped positions.
Remote or under seat Two activation options will be available, allowing riders to pick from either a remote or under-the-seat lever. While still likely to receive some minor changes before production begins, the lever employs an ultra-slim footprint that easily fits between the other controls on your bar, as well as being hinged for simple installation and removal. The under-the-seat lever is likely going to be less popular than the remote, but using it will reduce bar clutter, if that is a concern. It is bolted to the same mounting location as the remote actuation arm, and pushes the cartridge's plunger down in the same way when pulled.
Hydraulic cartridge Thomson isn't shy about admitting that the Elite Dropper's cartridge is outsourced to another company; they wanted to focus on the machined structure and design of the post and let a team with experience in hydraulics design take care of the internals. The hydraulic oil is held within the upper section of the cartridge (right), with the activation plunger at the very top. At the bottom is the nitrogen chamber that is pressurized to 135psi. This pressure is not adjustable, something that many riders have used in the past to adjust their seat post's return speed, simply because the cam design on the plunger allows the user to select rebound speed by how far the lever is pushed.
Non-adjustable nitrogen The Elite Dropper's outsourced internals are laser etched at the bottom of the post (left), including the nod to its Norglide bushings and Motul oil. The threaded silver bottom cap (right) allows access to the post's internals, while a specially-shaped plug at its center keeps users from letting the nitrogen gas escape accidentally.
Thomson also had a few other goodies on display, including an X4 stem that was fitted with a carbon fiber faceplate. How much weight does it save? Likely very little, but it sure does look rad.
They also had a neat seat binder tool that uses a magnetic 4mm hex wrench. The production version (note the very roughly shaped handle - this was just a sample) will likely use a 4mm hex key with a strong magnet placed behind it, allowing the tool to be held securely to the seat clamp but still allow riders to pull it off quickly to use elsewhere on their bike.
bikethomson.com
Author Info:
Must Read This Week
BTW does anyone know of a seat dropper post that has a cushioning affect (like a height adjustable office chair) that would work to take the sting out of a hardtail?
When post failed further I'd sit on it in the up position and slowly it would work it's way down again. It gave me another idea of a 'weight controlled post, where if you sat hard on it it would go down, then slowly come back up to height. It's essentially how the failure was functioning, Not sure how you'd fine tune that though, but it was kind of neat how the post self returned without pushing the button. Most of the time I use the post it's for a log, sharp corner, or a scary dip, and only on long descents do I want to lock it down.
over the years, I have destroyed the most hardcore products from Easton, Deity, Race Face Diablous, Azonic, X-Lite, Kore, DMR, etc = anything can be broken in the "right" situation, the most important thing is how that products "fails". Does it injure you? Or does it allow you to stop riding safely?
Thomson designed their Elite seatpost to have a "bending fuse", which means the huge force you placed on your saddle caused it to bend, rather than suddenly snap like many lesser seat posts will in the same situation you faced
you'd be surprised at how large the force of a bad landing from height combined with your body weight applied through your saddle into the seat post can actually be?
of course, Thomson will not "warranty" their product because they know exactly the huge force it takes to bend their seatpost, and I understand that it sucks you then had to buy another seatpost rather than get a free one from Thomson
but this design feature of Thomson, allowed you to ride out of the problem and safely stop - there is nothing worse than a crash caused by a component failure, or by that failure actually injuring your body by having a jagged seatpost stab you in the rectum or thigh muscle
Thomson are known for their superb engineering and design features, your post did its job in keeping you safe when you came up short. I have had the same situation as you, and actually snapped a Race Face seatpost leaving a jagged seat post shaft which thankfully did not injure me
The only issue was caused by myself, I snagged my baggy Oakley shorts on the remote lever whilst standing to climb and snapped it clean off
I was honest with SRAM about this problem, and they had the seatpost back to me within 4 days, fixed free of charge = very good back up
If Thomson's new post is anywhere near as good (or better) than Reverb then it will be a darn good product.
I always thought the best combination for a dropper post would be "Thomson post with Fox guts"
its like Henry Ford with the original Ford Model T (automobile) all over again
"any colour you like...as long as its black!"
...Oh, and stainless steel is magnetic, or at least basic stainless steel is; depending on the ferritic structure (i.e. nickel content)...
I'll definitely go for the dropper post if it is actually released on next spring.
That all said, Thompson's dropper does in fact look like a great product.
But I'll agree with the lever at the bottom. No moving cable ... That's what I hate on my Reverb
Thompson As far as the under the seat lever post. Don't bother. If the lever isn't on the bar the post won't get used enough to justify its extra weight.
I am really glad to see Thompson bringing a dropper post to the market. If its as good as everything else they make it will be one of the best if not the best.
singletrackworld.com/forum/topic/forca-vario-dropper-seatpost-gravity-dropper-clone-272
I bought one for my winter HT and snapped it in 6 month, they sent me a new one (not snapped it yet) Work Well. Being 27.2mm is a bonus
If you have a sub £500 bike then it’s a good dropper for you.
If you have a more expensive bike I would go for a more expensive post.
So Thompson get a good product at the right price = sell loads. Not quite there yet IMO
That thing just shouts out "perfection" ...and that magnetic hex wrench surely is a neat idea, although I always have the hex-kit in my rucksack anyways. I don't know how anyone could go riding without.
And to the folks complaining about price, a static (non-dropper) Thomson is $150, so what did you expect for a dynamic post?
.... isn't this the reason you have a Fox fork out front as opposed to a SR Suntour?????
Hey, many of the other posts are well-engineered, and real eye candy to boot! However their cost & durability keep the KS at the top of my list.
I think I will wait to buy until they correct that oversight.
Still with the floppy cable?!
We need more I beam options . These posts need to be made lighter