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Fair bicycle Drop Best UC Seatpost Offset Gives Most Riders Modern Bike Fit Options

Fair Drop Best UC offset 2-bolt seatpost head, universal fit
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The UC in this new Fair bicycle Drop Best UC stands for Universal Compatability. And that means this little gadget will bolt on top of pretty much every 2-bolt seatpost out there, to let riders update the geometry of their old bike or tweak the fit of new bikes. Following up on their original offset seatpost head that worked exclusively with the Reverb dropper post, now they are back with a universal fit solution for almost all mountain bike droppers, plus a bunch of the proprietary seatposts found on a lot of modern road and gravel bikes, too…

Fair Drop Best UC offset seatpost head tweaks bike geometry

Fair Drop Best UC offset 2-bolt seatpost head, 27mm offset head detail

A lot of the bikes we ride these days really limit how much adjustability you have with seat position. Since mountain bikers have mostly all shifted to zero-offset dropper posts, and so many current road & gravel bikes use proprietary seatpost shapes, you are pretty much at the whim of the bike designers as to where exactly your saddle ends up. Sure you can move your position front or back a centimeter or two. But if that doesn’t always put you in the perfect position for a comfortable fit and good pedaling performance, you are out of luck.

Fair describes in as being “stuck in the middle”.

Fair Drop Best UC offset 2-bolt seatpost head, slam your saddle forward

So they created their first Drop Best offset seatpost topper that shifted the saddle rail clamp on a Reverb dropper. And mountain bikers looking to tweak their ride jumped on this little problem solver. So then, Fair went back to the drawing board to figure out how to make the Drop Best more of a universal fit.

Universal Compatability Tech Details

Fair designed the resulting Drop Best UC to let give you an extra 27mm of forward or rearward position adjustment. And between 0mm and -11mm of stack height lets you keep or lower your position a bit. Add that to the safe clamping range of your saddle’s rails, and you gain a whole world of extra adjustability.

They achieved that with a low-profile modular cradle that can work on almost all 2-bolt vertical seatpost heads. Machined from high-strength 7075 aluminum, held together with US-made grade 12.9 bolts.

Fair Drop Best UC offset 2-bolt seatpost head, universal compatible prototype development

Fair developed the universal head by literally buying all of the most popular posts, and 3D-scanning them to ensure trouble-free fit. There was plenty of variation in clamp length, width & angle. Plus, fit for conventional round rails or oval 7×9 or 7x10mm carbon rails. But different bolt hardware became the real limiting factor – M5 or M6 (5 or 6mm), or custom hardware. And, if you aren’t 100% convinced of the fit, you can even download a 3D file from Fair and 3D-print a dummy to verify that it will give you the offset or angle that you desire.

Fair Drop Best UC offset 2-bolt seatpost head, seatguts detail

The Fair solution solved all of that, while “staying within of a couple of grams of the original design, yet still passing tests way above ISO MTB standards”. The whole setup weighs a claimed 139g (up to 174g in the heaviest configuration). But it replaces an average of 75g of stock seatpost head hardware. So, just a net 64g gain to greatly increase your saddle position adjustability

Fair’s ethos is ensuring everything they do is fair to the environment and fair to the workers who make your gear. So, it’s entirely Swiss-made, and everything from the product to its packaging is fully recyclable.

Modernize your MTB geometry or even dial it back

Fair Drop Best UC offset 2-bolt seatpost head, 2° slacker MTB seattube angle

Dropper posts are amazing, but their setback is fixed. And there’s huge variation in real seattube angle from one mountain bike to the next, new-to-old, XS-XL sizes, and some oddly bent or offset seattube frame designs. And it’s even tough for us who nerd out on the detail, to be 100% sure about what a brand’s “effective” seattube angle means on some bikes these days.

Fair Drop Best UC offset 2-bolt seatpost head, 2° steeper MTB seattube angle

I mean, personally, I want to know the effective seat angle at my saddle height. But that’s often not something I can easily find out from a new bike’s geometry chart. So what looks like a 74° angle could be off a degree or two when I sit on the bike. If that puts you out of the ideal position you wanted, a Fair Drop Best UC can typically get you back an extra 2°. Either steeper, or now so steep if your new bike feels like it’s pushing you too far forward.

That 2° could also be an awesome upgrade for your old mountain bike with an old school (read: slacker) seat tube angle. Steepen it up a couple of degrees and your weight will shift forward for easier, more upright climbing and improved front tire grip on the steep uphills.

And pretty much every mountain bike with a dropper can be tweaked with the new Fair Drop Best UC.

Tweak your road or gravel fit, too

Fair Drop Best UC offset 2-bolt seatpost head, steeper aero road

Proprietary seatposts can also be great, right? Free aerodynamic gains and super slick integration looks nice on your latest gravel or aero road bike. But you are often locked into the position your stock seatpost determines. Say you want to race your aero road bike at a TT or triathlon, or just want to get more weight over the front of your gravel bike. You likely are pretty limited without hunting down some rare alternate post. But even those will likely only add rearward offset, almost never forward.

Fair Drop Best UC offset 2-bolt seatpost head, slacker road bike

Just like on the mountain bike, the Fair Drop Best UC lets you tweak that road bike seattube angle by about +/-2°. Not everyone needs that extra +/-27mm of fore-aft saddle adjustment. But those who, do are gonna be psyched at how easy it can be for a Drop Best Road setup to cure what ails them.

It won’t fit quite as many road bikes, since many use 1-bolt or other side-bolted designs. But there are still plenty of vertical road 2-bolt seatpost heads out there, oftentimes with a hidden/upside-down front bolt.

Why offset an existing bike?

Fair Drop Best UC offset 2-bolt seatpost head, fix your existing bike's fit

Fair bicycle’s mission is to make your bike better. That doesn’t really matter if the bike is new or old.

Why not get the best fit and ride out of the bike you already have, instead of always having to buy something new to take advantage of the latest trends in bike geometry? Fair say, “The best bike is the one you don’t buy… If you are not racing seriously, we believe you can still have all the fun on a well-set-up older bike… So if our products can help that: mission accomplished.

Fair Drop Best UC – Pricing, options & availability

Fair Drop Best UC offset 2-bolt seatpost head, new universal compatibility options

The Fair Drop Best UC offset concept does offer almost “universal compatibility”, but it still requires you picking the correct hardware for the type of post you want to adjust. The complete offset clamp with probably the most common M5 bolts is the lowest cost at $134 / 125€. A full setup with M6 bolts or the special F21 tweak for 2021 Fox Transfer/RaceFace posts will run you $158 / 146€. The Fair Drop Best Road setup sells for $152 / 140€. But you can also buy different hardware kits down the road for $20-34/19-32€ if you want to swap from one installation to another. (Note: all prices above are approximate, as original pricing is in Swiss Francs CHF.)

Fair Drop Best UC offset 2-bolt seatpost head, 2021 Fox Transfer on MTB

All options are available now direct from Fair, in relatively small numbers. So snap one up quickly if you feel the need to tweak your bike’s geometry before the start of spring riding really kicks into full gear.


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1 month ago

This is great! I’ve been sniffing around for a new MTB and all these crazy-steep HTAs have me ruling out most bikes for my long torso and short legs. I’ll definitely be getting one of these with the new bike.

1 month ago
Reply to  FrankTheTank

Steep HTAs? Do you mean STAs?

1 month ago
Reply to  Brian

Yes. Yes I do.

FAIR bicycle
1 month ago
Reply to  FrankTheTank

Cool, good to hear, because that is just why we made it .)

24 days ago
Reply to  FAIR bicycle

See below pls

howard cain
howard cain
1 month ago

Hi will this fit an inline thompson post for road use ? Thanks in advance

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