In cycling, there is no quest pursued with as much fervor as that of saving weight. Light bikes are fast bikes, and therefore, even lighter bikes are faster still. Sure, there was even a time when people used drill presses and got creative with assorted tools to make their components even lighter, but technology has allowed us to move beyond that.
For FOX, it’s not enough to be as light as others, we believe in always pushing to be even lighter. With that in mind, we took on the challenge of adding an even more lightweight member to the Transfer dropper post family. Starting at 327g for our 27.2mm factory series, the SL is 25% lighter than our standard Transfer post, making it the lightest mainstream dropper on the market. With lever options for drop bars, flat bars, and 2x front shifters, it’s the perfect upgrade for gravel riders and diehard XC racers who want the performance of a dropper but not the extra heft.
FOX Transfer SL Specs
- NEW lightweight design
- NEW windows in lower post allow cable clamp/slack to be pulled from post side for compatibility with GRX-style dropper levers and minimizes extra cable housing length
- 2-position mechanical post that locks at the top and bottom only
- Longer travel configurations offer an increased exposed length for taller riders
- Shorter travel configurations offer shorter total length for smaller riders
- Coil spring for consistent return performance
- Internal routing only
- 27.2, 30.9 and 31.6 mm diameters
- 50, 70, 75, and 100 mm drop options
- 70-85 degree seat angles are supported
- 7mm and 7x9 "Ob-round" saddle rails supported
- 1x lever is Matchmaker, Shimano GRX, and I-SPEC EV compatible
- Available in Factory and Performance Elite Series (Factory post includes Ti hardware for additional 10g weight savings)
- MSRP: $399 USD (Factory) / $329 USD (Performance Elite)
FAQ
Why limit it to 75mm/100mm?
The intent was to make the lightest dropper posts on the market, mainly for XC applications. Limiting drop allowed Fox to optimize materials and material usage to achieve the weight goals.
Why are the saddle clamps different than Transfer?
Weight - Transfer’s saddle clamps are made to maximize travel for exposed post length (length of post not in the frame). In XC applications (100mm/70mm), exposed post length is not a limiting factor so minimizing post length does not help. Weight was saved in the clamps and upper post by allowing the clamps to sit slightly above the upper post (on Transfer the clamps and upper post overlap).
Why two-position vs. infinite adajust?
Weight and need – The two-position system is much lighter than an infinitely adjustable system. In XC applications, the post is almost always up or down (not in between) so there is no benefit to intermediate positions.
Why mechanical?
Weight! No hydraulics saves the oil weight. Transfer SLs posts have empty space where oil would exist in a hydraulic post.
Why does it make more noise when locking than Transfer/other hydraulic posts?
The mechanical locking mechanism has hardened steel balls that engage in internal grooves in the upper post to lock the post in the two travel positions. This is the noise one hears as the post locks into position. In hydraulic posts there is no such mechanical locking function, so no locking noise is present.
Why is there an XL version, I thought seatposts were supposed to be as short as possible for a given travel?
Some bike/rider combinations cannot achieve correct saddle height with the ‘normal’ length Transfer SL. For these combinations the XL exists. For most riders/bikes the Transfer SL does achieve desired saddle heights so weight is optimized for the majority of riders.
Why does the saddle angular free play feel different from Transfer/other posts?
Transfer SL uses a unique weight-optimized anti-rotation mechanism to keep the upper post from rotating in the lower post. The mechanism has two preloaded bushings so there is zero angular ‘free play’ at the saddle. Instead there is a spring-loaded feel if the saddle is twisted. Most dropper posts use rigid parts (Transfer uses brass pins) to prevent angular rotation of the upper post, which results in a small amount of angular free play until the rigid parts engage.
Why/How does the post compress so easily but still return so quickly?
Highly preloaded low rate spring and no speed decrease from hydraulic oil flowing.
Why does it use a mechanical spring vs an air spring? I thought air was lighter than metal.
Air is lighter than metal, true. But air must be sealed to be a spring. Using a mechanical spring eliminates the need to create a sealed air chamber and along with that all the required seals. Since the spring needed to return the post is so light, the mechanical design is lighter than an air sprung version since no sealing is required. This is not true for forks and shocks where the spring must support the bike and rider – the Transfer SL’s spring only extends the post, it does not support rider weight.
Why is this post more sensitive to collar torque than Transfer?
Transfer SL uses thin walled tubes to minimize weight. Due to this, some seatposts clamps can deform the lower portion of the post enough that it interferes with the internal bushings. This can cause the seatpost to bind, usually preventing return to the top locking position. No worries though! Simply decrease the collar torque until the post moves easily up and down. For Transfer SL, a maximum collar torque is specified to prevent post damage, but the correct torque is the torque that holds the post in position under rider weight but does not bind the post from returning to the top locking position. This torque can be different for each rider/bike/clamp combination.
Can the Transfer SL post be serviced by a customer or shop?
There are several special tools required to service the Transfer SL. With those tools, service is easy for a customer or shop.
Are the recommended service internals the same as the regular Transfer? If different why?
Suggested service intervals are the same as the regular Transfer.
Is the post e-MTB approved?
Yes, but this is an odd combination.
What similarities and differences are there between the Transfer SL 31.6 and new 27.2 version?
The Transfer SL 30.9/31.6 are functionally the same as the 27.2 version. All rider interfaces are the same (saddle clamps, cable clamp) and setup is the same. The differences between the 31.6/30.9 and 27.2 are internal. The 27.2 uses traditional anti-rotation pins so there is some saddle angular free play with hard rotational stops. The 30.9/31.6 use preloaded anti-rotation bushings so there is no angular free play, but the rotational stops are progressive (they feel like springs).
How does the return speed compare to the Transfer?
Return speed is slightly faster than Transfer since there is no hydraulic damping.
For more information, head on over to www.ridefox.com.