Causeway GR1 - GRX815 Di2 1x11

Causeway GR1 - GRX815 Di2 1x11

Regular price £3,499.99
0 in stock

We wanted to take the hassle out of buying your next bike, so we worked closely with our partner brands to create the essential gravel bike for all riders and abilities. 
The specification is based on our own rider testing around the trails of Northern Ireland, and reflects a truly reliable and high performance bike build.

Don't like it, no fuss, just switch it up for the parts you want or upgrade to a higher specification component for increased performance.

'Fit for you' 

Everybody is different, and we know that cockpit configuration can make or break your riding experience.

Dont like wide handlebars, or fancy a different wheel size? Maybe you want to add a dropper seat post for that extra confidence when the trail takes a turn and points you downhill. You can switch out any of these in our bike builder and customise your ride just the way you want it.

Build my bike

Starting with our basic GR1 build, this will set you up to tackle any terrain with confidence and authority. 

Be it a weekend gravel grinder, or a relaxed cruise through the local woods, our basic GR1 wont come unstuck or let you down. 

The FUSTLE Causeway straps you in to the drivers seat from the moment you go to place your order. Once you've customised your sizing and selected the component range to best suit your ride its time to get amongst it! With a agressive 69' head angle and dropped top tube for a lower stand over the Causeway oozes confidence without sacrificing agility in your ride.

Frame: The Causeway GR1 6061 grade aluminium frame is compatible for both 650b and 700C wheel sets, with 142mm x 12mm rear axle spacing and 100mm x 12mm on the front, secured into your frame by bolt through axles. With internal cable routing throughout and a modern day 31.6 seat tube, your options from static seat posts to dropper posts are endless. Included is the PRO Koryak static seatpost with the option to upgrade to a 120mm dropper seat post. A removable bridge for full length mud guards to help tackle whatever winter throws at you. A variety of cockpit options to help you lock in that feel your looking for from the moment you throw your leg over your Causeway GR1, whether its an aggressive trail ripper or your weekend adventure bike, the PRO Koryak bar and stem combinations have you covered. All locked in place with the trusty FSA 1 1/8 - 1.5 inch headset.

Fork: The Carbon Fibre Causeway fork and tapered steerer has been engineered and manufactured as one piece to ensure strength and durability. Being both 650b and 700C compatible and allowing for tyre clearances up to 50mm on 700C. Three fixing points on either side of the fork, allowing for mudguard, paneers, water bottle etc etc. 

Standard Specification; (We hand picked these parts as a great spec for most riders, but feel free to upgrade wherever the option appears)

Wheels: WTB Speed Terra 700C

Speedterra wheels provide dependable tubeless performance capable of enduring many seasons of riding. All Speedterra wheels utilize four Enduro radial bearings, an open-cavity design, sleeved joints, water transfer decals and a reliable 4-pawl freehub design with 10 degrees of engagement. Double butted spokes and black brass nipples provide. All sizes of Speedterra wheels come with TCS tubeless tape, Solid Strip and brass TCS valves preinstalled. Customizable with centerlock or six- bolt rotor mounts, as well as Shimano or XD driver bodies. All 23mm variants are 28-hole with a 100x12mm front hub and 142x12mm rear.

Tyres: WTB Resolute 42

Resolute 42 is the ultimate all-weather gravel tire for those who believe there is one perfect tread pattern for all your rides. Truly all-season in nature, we call this our set-it-and-forget-it tyre that keeps on keepin’ on.


  • Widely spaced square knobs deliver consistent traction while shedding muck with ease.
  • Retro-esque tanwalls provide modern performance in a classic look.
  • Performs well in all conditions, no need to swap tyres based on the weather.

Saddle: WTB Volt Pro

The Volt is WTB most popular mountain saddle. Shaped for speed and comfort, time tested and proven, the Volt makes for an incredibly versatile saddle that has gained endless acclaim among riders.

DIMENSIONS: 135, 142 & 150 x 265mm


  • Medium padding thickness and subtle curves make the Volt our most popular mountain saddle.
  • An upward curved tail and gentle drop to the nose provide something to push against while pedaling.

Groupset: Shimano GRX Di2 RX815 1x11 groupset 

The Shimano GRX Di2 RX815 1x11 electronic groupset results from a two-year close collaboration with Gravel enthusiasts from around the world. It includes a 1x crank with a 42 tooth chainring, Di2 rear derailleur, disc brake with STI Di2 right and left shift levers (programmable to 1x = without shift function), chain and cassette (Ultegra or MTB). Shimano didn't want to tell the Gravel specialists what to ride, but asked them what they wanted instead. Many unpaved paths were explored, off-road races contested, bikepacking tours undertaken, a lot of dust swallowed and mud bath galore. The result is the world's first Gravel-specific electronic component groupset, the GRX Di2 by Shimano.

Content of the Shimano GRX Di2 RX815 / RX817 1x11-speed groupset:

  • GRX Di2 ST-RX815 shift/brake lever (left + right)
  • GRX BR-RX810 disc brake caliper (front + rear)
  • GRX FC-RX810-1 crankset
  • GRX Di2 RD-RX817-GS Shadow RD+ rear derailleur - medium
  • Deore XT CS-M8000 cassette (11-40 or 11-42 teeth)
  • CN-HG701-11 chain - 116 links
    (incl. SM-CN900 Quick Link chain connector)


Please note that the RD-RX817-GS rear derailleur is only compatible to the CS-M8000 cassette with the 11-40 and 11-42 teeth sprocket ratio.

Shimano GRX Di2 ST-RX815 shift/brake lever

The electronic/hydraulic Shimano GRX Di2 ST-RX815 dual control lever provides Gravel inspired ergonomics. Particularly striking is the shape of the handle whose hood head is raised to prevent misalignment while the recessed finger notch prevents the hand from slipping upwards. Like the handle, also the lever features an anti-slip coating for greater mixed-terrain control.

In terms of shifting performance the 2x11-speed GRX Di2 STI lever can take full advantage of the well-known digital precision of the Shimano Di2 electronic shift systems and the Synchronized Shifting technology. In contrast the braking performance is optimized by the brake lever's rotary axle which is positioned 18 mm higher than usual and Shimano's SERVOWAVE technology improving the lever's modulation ability.

In addition, the programmable Di2 shift/brake lever features three switches (two on the side and one on the hood's top) that can be used to operate third-party devices such as compatible lights or bike computers. In order to meet the individual needs of the driver, the hydraulic brake lever offers reach and free stroke adjustment as well.

Shimano GRX BR-RX810 disc brake caliper

Never hesitate to tackle rough surfaces with the hydraulic Shimano GRX BR-RX810 caliper. In doing so Ice Tech ensure excellent heat dissipation while the BR-RX810's 2 ceramic pistons guarantee excellent braking performance under all conditions. The Flat Mount system makes it possible to attach the disc brake caliper directly at frame or fork. Trouble-free and simple maintenance is provided by the proven One Way Bleeding concept and the Easy Hose Joint System which simplifies brake hose exchanges (brake hose sold separately).

Shimano GRX FC-RX810-1 crankset

Shimano's GRX cranks are designed to handle a wide variety of terrain and riding styles and feature a 2.5 mm wider chainline for more freedom in frame design and the use of wider tires.

The GRX FC-RX810-1 Hollowtech II crankset relies on a 1x11-speed drivetrain concept and offers the optimum gearing for every terrain and riding style thanks to Shimano's wide range of cassettes and sprocket ratios. For the aluminium crank with a 50.1 mm chainline you can choose between a 40 or 42 teeth chainring which is suitable for the use with HG-EV and HG-X11 chains.

Shimano GRX Di2 RD-RX817-GS Shadow RD+ rear derailleur

The electronic Shimano GRX Di2 RD-RX817 rear derailleur is characterized by quiet, smooth, precise and reliable shifting even in the most demanding terrain. This is mainly due to the Shadow RD+ chain stabilisation system which prevents the chain from slapping and dropping as well as from unnecessary movements of the derailleur's cage, thus ensuring uninterrupted shifting performance. That is why an On/Off switch can be found next to the upper pulley, much like Shimano’s mountain bike derailleurs. When activated the rear derailleur pivot takes a firm hold to reduce excessive movement, noise and general "chain chatter".

The RD-RX817 rear derailleur is suitable for 11-40 and 11-42 teeth cassettes. Jockey wheels with 11 teeth ensure a reduced noise level and increased riding comfort.

Bottom Bracket: SM-BB72-41

SHIMANO ULTEGRA - Bottom Bracket - Press Fit - HOLLOWTECH II - 86.5 mm shell width


Rotors: Shimano RT76

SMRT76 rotors give excellent performance using the 6-bolt mounting system. The precision cut stainless steel braking surface improves pad clearing in muddy conditions while aiding cooling under high load.

(Optional upgrades and Centrelock options are available)

Handlebar: PRO Discover Alloy

PRO's Koryak products are named after the Koryak highlands of Eastern Siberia. The robust all-mountian-parts bring you the confidence of being extremely resistant. Highest quality aluminium brings the ideal balance between weight and stiffness. High quality material and cool optic to go for the limits.

Available with a choice of drop flare, this hardy handlebar lets you take to the loosest and roughest terrains with control and poise. Featuring an ergonomically-focused top section with an oval-shaped centre, the bar gives a natural position for your palms when riding tall, while the size and geometry of the drops enhance comfort when getting your head down.

Built from a sturdy and durable alloy, it copes with the most extreme conditions and has specially placed cable holders for use with Shimano Di2 shifting systems, making this Discover bar a dazzling choice for the rough and ready rider.

Stem: PRO Koryak

PRO's Koryak products are named after the Koryak highlands of Eastern Siberia. The robust all-mountian-parts bring you the confidence of being extremely resistant. Highest quality aluminium brings the ideal balance between weight and stiffness. High quality material and cool optic to go for the limits.

- Rigid trail -An XC and 'All-Mountain' stem made of forged and cnc-machined 7075 aluminium. Strong & durable 4-bolt headlock clamp-design.
- 0 degree - available in different length.
- Bar clamp: 4-bolt, detachable
- Material: 7075 aluminium, cnc machined

Seatpost: PRO Koryak Alloy

PRO's Koryak products are named after the Koryak highlands of Eastern Siberia. The robust all-mountian-parts bring you the confidence of being extremely resistant. Highest quality aluminium brings the ideal balance between weight and stiffness. High quality material and cool optic to go for the limits.

  • DIAMETER: 27,2 & 31,6 MM
  • SETBACK: 20 MM