The Ultimate Gravel Bike Build

The Ultimate Gravel Bike Build

March 07, 2019

Mission: Build the most capable, multi-discipline, adventure bike possible. 

Gravel riding has taken the world by storm, and for good reason - what could be better than a muddy ride through bridleways and gravel trails. No cars. A clear path ahead. Uncharted territory.

At Tailfin, we wanted to take our engineering passion and challenge ourselves to put together the world’s best adventure bike (although we appreciate the word ‘best’ is in the eye of the beholder) - a dream gravel rig that can go anywhere, do anything and leave you smiling ear to ear.



The dream build is centred around the stunning OPEN U.P.P.E.R frame and OPEN U-Turn Fork. Its combination of low weight, fast but comfortable road riding position, and clearance for mountain bike tyres, has helped this build achieve the status of greatness. The ability to be able to change from road riding tyres for your weekly club ride, to mud-crawling MTB tyres gives this bike unlimited scope for the types of adventures we can take it on. Big thanks to Gran Fondo for making our lives easier with their incredibly comprehensive gravel test…


Frame: OPEN U.P.P.E.R. 880 grams
Fork: OPEN U-Turn Carbon. 370 grams



After contemplating a carbon cockpit, we opted for the reliability and durability of aluminium. At the same time we were looking for a subtly flared bar to offer improved comfort for riding in more rugged terrain. We opted for Easton’s EA70 AX 16 degree alloy drop bar and stem.


Handle Bar: Easton EA70 AX 44cm. 290 grams
Stem: Easton EA90 130mm. 145 grams


We wanted a 1x system for reliability and simplicity so opted for the SRAM Force 1 groupset. However, knowing that we were planning on using this bike for bikepacking we wanted more range than the off the shelf 10-42 tooth SRAM cassette. We therefore swapped it out for the e*thirteen TRS Race cassette which offers a massive 9-46 tooth,  511% range. Combined with a 38T chainring, we knew this would give us enough gears at the top and bottom of the range for almost every scenario.

OneUp Aluminium Flats for the feet. There's a debate to be had, but for some, flat pedals offer a lot of advantages on bike-packing trips. Firstly, for real adventures, you may have to rely on your legs in more ways than just the spinning - carrying your steed over fences or streams for example. Secondly, flat pedal shoes tend to be much more comfortable: when we're opting for distance and comfort over speed, this was our choice at the time, although I’m sure we’ll swap in clipless pedals when we take it on less gravel-focused rides.


Brakes and Shifters: Sram Force HRD Shift-Brake Control Double Tap. 471g left + 431g right
Cranks: Sram Force 1 Carbon 175mm. 679 grams
Cassette: Ethirteen TRS Race 11-Speed Cassette 9 x 46. 303 grams
Rear Derailleur: Sram Force 1 11-Speed. 261 grams
Pedals: One Up Components Aluminium Pedals. 355 grams


Seat & Seatpost

Knowing full well that we wanted a very aggressive gravel bike, we absolutely wanted to install a dropper post. This was actually one of the main reasons we opted for a 1x system. By installing a Force 22 front Yaw shifter, it's possible to remove the ratchet and convert the front shifter to a dropper remote (pretty sure this voids the SRAM warranty) This modification has arguably been the most successful aspect of the build.

Big thanks to the guys who made this video for showing us how…  

Given the lack of droppers for 27.2mm seatposts and without knowing how well this was going to work, we went for a fairly basic dropper post - the KS ETEN-I  - we will likely upgrade this down the line. After testing this out - it works like magic - being able to drop the seat when the terrain gets rowdy offers huge amounts of confidence.

On top of our post, we are running a Fabric scoop pro radius saddle 142mm. It’s a personal favourite due it’s low weight and comfort - it has carbon rails but a flexible Nylon base which makes a huge difference when spending hours in the saddle.

Seatpost: KS Eten i 27.2mm 100mm. 590 grams
Seat: Fabric Scoop Pro Radius. 162 grams  



Wide, light and strong; we have opted for the widely praised HUNT 30 carbon gravel disc wheelset. With exceptional build quality, weight, durability and price, it's hard to look past them. These are mounted with WTB Senduro 650bx47 road plus tyres that we have set up tubeless with Stans race sealant. These chunky tyres will be ideal for big off-road days, especially in winter, plus they look insanely good. For more road-focused trips we will be putting on a pair of WTB Byways.


Wheels: Hunt 30 carbon gravel discs wheelset.  650b. 1479 grams
Tyres: WTB Sendero 650bx47 road plus TCS.  530 grams each



Finally - the AeroPack. Zero sway, top-loading, attaches in seconds and offers class-leading ride quality - this bike bag will save you time and irksome faff when packing and unpacking during stops. Launching very soon. (Get it here.)


Tailfin AeroPack Carbon. 600 grams. 


Full List of Parts:

Frame: OPEN U.P.P.E.R. - 880 grams -

Fork: OPEN U-Turn Carbon - 370 grams

Wheels: Hunt 30 carbon gravel discs wheelset. 650b - 1479 grams -

Discs: Ashima Airotor 160mm. - 85 grams each

Tyres: WTB Sendero 650bx47 Road Plus TCS -  530 grams each -

Brakes and shifters: Sram Force HRD Shift-Brake control double tap - 471g left 431g right

Handle Bar: Easton EA70 AX 44cm - 290 grams -  

Stem: Easton EA90 130mm - 145 grams

Cranks: Sram Force 1 Carbon 175mm - 679 grams

Cassette: Ethirteen TRS Race 11 Speed Cassette 9 x 46 - 303 grams -

Rear Derailleur: Sram Force 1 11 speed - 261 grams

Chain: Sram PC 1170 11 speed. 114 links - 256g grams

Pedals: One Up Components Aluminium Pedals - 355 grams -  

Seatpost: KS Eten i 27.2” 100mm - 590 grams -

Seat: Fabric Scoop Pro Radius - 162 grams -

Bottle Cages: Vel Carbon i-Cage - 2x 28 grams

Bikepacking Gear: Tailfin AeroPack - 640 grams -


With Many Thanks To...

Film & stills both shot & edited by Sam Taylor:

Big thanks to Bike Fit James for the use of his magnificent shop his talented wrench John.


Tailfin #RideFastWithMore

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