FOX launched the Transfer SL, an ultra-light dropper post designed specifically for cross-country riding. As the only dropper in this test field with fully mechanical internals, it features titanium saddle clamp bolts – which makes it a truly lightweight option for racers.

FOX offer not only the Transfer and wireless Transfer Neo, but also the ultra-light Transfer SL, which was designed specifically for XC and gravel bikes. That said, weight weenies can easily run this dropper on an enduro bike too – which we did to tell you how it performs!
The FOX Transfer SL is the only dropper post in this test to rely on fully mechanical internals, which is the most effective way to shed a significant amount of weight. Instead of relying on oil and air, it uses an internal spring. Additionally, titanium bolts in the saddle clamp help reduce weight too, bringing the Transfer SL’s system weight to a mere 495 g – including the remote, cable, and housing. This makes it the lightest dropper post in the entire test field, though it’s worth noting that it’s also the only model with 100 mm of travel. For comparison’s sake, the 170 mm Crankbrothers Highline 11 tips the scales at 626 g. However, the FOX Transfer SL’s featherweight comes at a price: at € 519, it’s not exactly a bargain, sitting above average within the test field in terms of price.
You can find an overview of this comparison test here: The best dropper post.
The FOX Transfer SL is available in three diameters and several travel lengths:
- 27.2 mm diameter: 50 mm, 70 mm of travel – a standard size for drop-bar bikes
- 30.9 mm diameter: 75 mm, 100 mm of travel
- 31.6 mm diameter: 75 mm, 100 mm, 125 mm, 150 mm of travel
The travel options alone make the Transfer SL less suitable for enduro riding, where travel lengths of up to 240 mm are now common, as seen with the FOX Transfer Factory or OneUp V3.
The Factory variant of the Transfer SL we tested comes with the fancy Kashima coating, which, according to FOX, reduces friction, improves durability, and makes the stanchion more scratch-resistant. However, based on our practical experience with FOX Factory suspension, the reduction in friction is negligible – the Kashima coating’s primary appeal lies in its prestige factor. For € 449, you can get the Performance Elite version with a black-anodised stanchion, which forgoes the Kashima coating and titanium bolts, offering a more budget-friendly alternative.
With 100 mm travel the FOX Transfer SL Factory has 271 mm insertion depth, which is quite a lot for such a short-travel dropper post, especially next to the gravity-oriented models in this test. For example, the 170 mm Crankbrothers Highline 11 has an insertion depth of 286 mm. However, since the Transfer SL is primarily designed for cross-country bikes, the key consideration is not insertion depth but saddle extension. Given the limited travel, you might have to extend the actual post further out of the seat tube to achieve the desired saddle height. To optimise saddle extension while keeping insertion depth to a minimum, FOX integrated the actuator into the dropper housing – a clever design feature.
FOXs Transfer SL has 53 mm stack height, which is slightly taller than the average in this test. For comparison’s sake, the PNW Loam Dropper has 47 mm, while the FSA Flowtron has 50 mm.
The Transfer SL uses a spring-based mechanism rather than hydraulics, which makes it the only dropper post in this test with fully mechanical internals. This design prevents the post from stopping mid-travel, which you can do with hydraulic models. For those concerned that a spring might be heavier than air, FOX engineers prove otherwise: the overall weight is reduced thanks to fewer seals. That said, seals are still used to keep dirt out effectively.
Every detail of the Transfer SL is engineered to shed weight, including thinner walls in the lower part of the post. Therefore, it’s crucial to stick to the recommended torque settings to prevent overtightening and thus damage to the post.


As previously mentioned, the actuator design sets the FOX Transfer SL apart from other models in this test field, and its installation is slightly unconventional too. The cable is clamped to the actuator with a screw, which is only accessible through two openings – or “windows” – in the housing. This design also allows for increased extension, achieving a minimal insertion depth to compensate for the shorter travel. You don’t necessarily need to cut off the barrel at the end of the cable, but if you’re focused on weight optimisation, it’s an option.
Aside from the unique actuator design, installing the FOX Transfer SL is just as straightforward as with conventional FOX droppers, and, like the Transfer Factory variant, the remote is sold separately for € 118. However, Matchmaker and I-SPEC adapters are included in the box, allowing seamless integration into the cockpit. The saddle is clamped with two classic bolts – made from titanium in this case – with barrel nuts as counterparts. Be careful when tightening the bolts with a multitool to avoid damaging the stanchion.
We put the FOX Transfer SL through its paces on our home trails and were very impressed. Operating the remote and compressing the dropper both require very little strength, and the FOX Transfer SL quickly releases its 100 mm of travel. The familiar, loud “clunk” noise of the FOX Transfer Factory is even sharper in the SL variant due to its mechanical internals.
Initially, not being able to stop the post mid-travel took some getting used to. However, with this little travel, it wasn’t really a problem. Throughout the entire testing period, the Transfer SL performed reliably without any issues.
Conclusions about the FOX Transfer SL dropper post
The FOX Transfer SL stands out with its Kashima coating and a well-thought-out mechanical design that sets it apart from other dropper posts. While the lack of mid-travel adjustments takes some getting used to, it’s not an issue for its intended use. In return, you get an exceptionally lightweight dropper post – granted, with limited travel, which aligns perfectly with the intended use on short-travel bikes in the XC segment.

Tops
- Very fast extension speed
- Extremely lightweight

Flops
- No mid-travel stop
- Not exactly budget-friendly
For more information, visit ridefox.com
The test field
You can find an overview of this comparison test here: The best dropper post.
All dropper posts in test: BikeYoke REVIVE 3.0 | Crankbrothers Highline 11 | FOX Transfer Factory | FOX Transfer Neo Factory | FOX Transfer SL Factory | FSA Flowtron Dropper Post | Kind Shock LEV Circuit | LIMOTEC H1 | OneUp V3 | PNW Loam Dropper | RockShox Reverb AXS | SDG TELLIS V2 | TranzX EDP01 | Turnon Bunker | Wolf Tooth Resolve rev2
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Words & Photos: Robin Ulbrich