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Fox Transfer SL jettisons hydraulics & air spring to become new lightest dropper post?

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Even with their obvious benefits, at first, dropper posts were a hard sell for the XC crowd. That was mostly due to the added weight. But with World Cup XC tracks getting more challenging, and racers looking for every advantage possible, even the most gram-conscious have embraced the dropper.

And now that Fox has given their Transfer the SL treatment, we’re guessing this is just the beginning.

Fox Transfer SL dropper post extended

No, there isn’t a special ‘drillium’ edition of the Transfer. Instead, the SL version uses entirely new internals to make it the lightest Transfer yet. Maybe the lightest dropper post yet – Fox calls it the “lightest mainstream dropper available.”

Fox Transfer SL dropper post factory

While the Transfer utilizes an air spring with a hydraulic mechanism and infinite travel adjust within the travel range, the Transfer SL is completely different. Instead, it is a completely mechanical post with only two locking positions – up or down.

All of this was done in the name of saving weight. Eliminate the hydraulics, and you get rid of the heavy hydraulic fluid. Eliminate the air spring, and you get rid of all the seals and parts needed to contain pressurized air to act as a spring. Eliminate the infinite travel adjust, and you end up with a lighter two-stop system.

Fox Transfer SL dropper post clamp head

Additional weight savings come from the redesigned saddle clamp, which sits slightly taller than the saddle clamp on the original Transfer. Fox redesigned the current Transfer with a saddle clamp that sits as low as possible – which is important when you’re trying to maximize dropper post travel in many frames. But with short travel droppers in XC frames, that’s not really an issue, so the new head (which looks a lot like the old Transfer head) is lighter. With it, you’ll be able to reach 70-85° saddle angles and clamp 7mm round or 7x9mm ‘ob-round’ saddle rails.

As a result, the Transfer SL weighs in as low as 327g for the Factory 27.2mm post with 50mm travel. That works out to about 128g lighter than a 2021 Transfer.

Fox Transfer SL dropper post opening window

Other than the decreased weight, the Transfer SL gets another improvement with a revised cable anchor. Now housed inside the post thanks to the two windows that allow access, you can anchor either end of the cable at the post. That allows you to run dropper post levers like Shimano GRX drop bar levers – or any dropper lever for that matter.

Fox Transfer SL dropper post black Performance elite

Offered in 27.2, 30.9, and 31.6mm post diameters, travel is kept to a minimum of 50 and 70mm for the 27.2mm posts. The 30.9/31.6mm posts get longer 75mm and 100mm travel options which are naturally a little heavier. There’s also an ‘XL’ post which is still 31.6mm diameter and 100mm travel, but has a longer 430mm length for taller riders who need a more exposed post in their bike.

Offered in Factory (Kashima with Ti hardware) and Performance Elite (black), the posts will sell for $359 for Factory or $329 for Performance Elite.

Sizing Details

• 27.2 x 50mm, 80mm min insertion, 248mm max insertion, 350mm extended length, Starting Weight: 327g
• 27.2 x 70mm, 80mm min insertion, 248mm max insertion, 370mm extended length, Starting Weight: 338g
• 30.9/31.6 x 75mm, 80mm min insertion, 225mm max insertion, 355mm extended length, Starting Weight: 342g/352g
• 30.9/31.6 x 100mm, 80mm min insertion, 225mm max insertion, 380mm extended length, Starting Weight: 347g/359g
• XL 31.6 x 100mm, 80mm min insertion, 275mm max insertion, 430mm extended length, Starting Weight: 399g

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12 Comments
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Sammy
Sammy
3 years ago

Neat. So how does it work? It’s not hydraulic or pneumatic, so it must just have a big physical spring in it? Nod to gravity posts there

George French
George French
3 years ago
Reply to  Zach Overholt

Very hard to imagine a steel spring being lighter than an air spring, seals weight next to nothing.

tinytim
tinytim
3 years ago
Reply to  George French

I would think this uses a titanium spring

Shafty
Shafty
3 years ago
Reply to  George French

The seals don’t weight much, but the structure to support the pressure can weigh a bit. Also, the tubing needs to be thicker to prevent expansion and retain consistent sealing. Lower friction without the seals mean the spring can be pretty light. A proper pneumatic only post could be extremely light, but you still need a locking mechanism that can deal with the acceleration. Specialized command post does it like that, but they return so fast that they can self destruct. Fox had the DOSS before, which was pretty good, so I’m hopeful for this one.

Bigbikr
Bigbikr
3 years ago

Interested to see if Fox quietly moves away from the 21 Transfers new clamp as while I love the post and it’s performance that clamp does nothing but creak for me. Given I am a bigger rider.

BL
BL
3 years ago
Reply to  Bigbikr

Contact Fox – they will send you a new and improved clamp. – my original creaked and loosened all teh time.

Hamburgi
Hamburgi
3 years ago
Reply to  BL

You know whats my problem? I cant moce the saddle nose further down, because the clamp design didnt allow this, the screws are tho short and the baseplate have got a metal nose like a stopper. So i have to change the whole dropper post…. the dropper is on a XC bike

reubenmc
reubenmc
3 years ago

Not as light as 9.eight Fall Line R… I guess 9.eight isn’t “mainstream”?

-s
-s
3 years ago
Reply to  reubenmc

If only 9point8 made a 27.2. I guess Fox is lighter since 9point8 doesn’t have a comparable size. When matched up size for size, 9point8 wins. I have two R’s, great posts.

Gillis
Gillis
3 years ago

@reubenmc

There are only one of each brand that have comparable size and length:
Fox: 30.9, 380mm length, 100mm stroke, 347g
9.8: 30.9, 375mm length, 125mm stroke, 376g

Beyond these it comes down to personal needs, and either brand could come out lighter.

Eggs Benedict
Eggs Benedict
3 years ago

What about the one with all the holes in it, the title photo, when is that going to be available?

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