For the last few years we’ve attended the North American Handmade Bicycle Show, we’ve always made it a point to visit the FiftyOne Bikes booth, where the custom carbon road bikes made in Ireland have never disappointed. Well, only that we’ve never tested one and that’s because they’ve always offered to build us a custom bikes and as a rule,  RBA doesn’t test custom built bikes.

Be that as it may, beyond the always impressive finish of the bikes, a visit to the booth would also bring the chance to catch up with company founder Aidan Duff (r) who has a former Euro road pro always has some great stories to tell of the real deal world of pro bike racing  (for an example, scroll down to see how the bike got its name).

And now, we have the Assassin gravel bike which can be had in factory sizes…so a test bike is on the way!



Press Release

The Assassin is a progressive gravel bike with a massive breadth of capability and compatibility. Its adjustable geometry is the key to your personal confidence. Rider preferences on bike handling vary and gravel trails vary even more, so one size does not fit all. The solution is our usage-tailored handling, giving you confidence whether you want to race, explore, tour or shred. This is how we use our custom-building experience of creating bespoke geometry to make a better factory bike.

The Assassin is designed around a long top tube/short stem concept, similar to that of modern mountain bikes and in keeping with its progressive, slacker geometry. Reach to the handlebar is maintained while the front centre (BB to front axle) and wheelbase is extended. This increases stability and confidence, especially on rougher descents, and eliminates toe overlap in all sizes.

We knew exactly how we wanted the Assassin to ride and our experience and expertise in custom building meant we also knew how to achieve that. The Assassin is made with Toray T1100, 800 and 700 fibres, each deployed according to their relative attributes, resulting in a tough gravel frame that weighs just 1050g (size M), rewards your efforts like a great road bike and provides the comfort you want when the ride is measured in days not hours.

Because we love gravel riding and because we felt that we could use our vast experience of building custom bikes with individually-tailored geometry to bring something new and better to the gravel sector. We understand that the geometry required to deliver a feeling of confidence varies from one individual to the next and we saw a way to deliver that using flip chips that we felt had so far been missed.


The Assassin gives total freedom of choice to build your bike to suit your riding and terrain:
• 47mm tyre clearance in both 700c and 650b
• 1x or 2x, up to 50/34
• Two front and three rear axle positions
• Dropper post and Di2 jointly compatible
• Front dynamo internal routing
• Fender and rack mounts, front and rear
• 4 portal bosses + 2 bottles
• Mild, Wild or custom paint

Everyone: explorers, shredders, racers, bike packers and anyone else who loves getting away into the countryside. The Assassin’s adjustable geometry and category-leading compatibility maximize performance in every situation, allowing one bike to do the job of several, without compromise.

At the rear, two chips offer three axle positions, adjusting the effective chainstay length and overall wheelbase in 5mm increments. Go shorter for more agility, go longer for extra stability, or take the middle option if you want a balance of each.

At the front, the chips offer two positions, High and Low. The ‘Low’ position gives a longer trail and slacker head tube angle, suited to more aggressive riding on more challenging terrain; the ‘High’ position creates shorter trail and a steeper head angle, ideal for gravel races or rides on back roads and less rough terrain.

• Long and Low = rugged terrain, more MTB feel, likely on wider tyres
• Short and High = milder gravel, more road bike feel, likely on narrower tyres
• Experiment to find the combination that suits you and your riding best

Whereas some bikes seek to maintain a constant trail figure when switching from 700c to 650b wheels, that’s the exact opposite to our goal. The Assassin’s flip chips allow you to tailor the geometry and handling to how and where you ride. Having refined the geometry options so carefully, we then ensured that the crucial trail figures remain consistent across all frame sizes.

The Assassin launches with two paint options: British Racing Green and Rothmans Racing Blue. Additionally, for an extra cost, customers can choose a bespoke paint design. As a custom builder, our highly creative, original and beautifully finished paint schemes have always helped our bikes to stand out from the crowds and to allow our customers to feel that they are riding something truly personal and unique. That’s an experience that we want to share with gravel riders, too.

The Assassin has two bottle cage mounts, plus four extra portal mounts on the toptube, downtube and fork legs, and rack mounts, too.
Rear rack – 15kg
Front rack – 5kg
Fork leg mounts – 5kg each

In 1910 the Tour de France tackled the high mountains for the first time, with not one but four high passes in the Pyrenees, including the mighty Col du Tourmalet, in a single stage of over 320km and 6000m. At that time, every road was gravel and those in the mountains were especially rough.

Summiting the fourth climb, the Col d’Aubisque, the leading rider and eventual stage and race winner, Octave Lapize, was furious at the stage’s excesses and screamed at the race’s deputy director, Alphonse Steinès, “Vous êtes des assassins! Oui, des assassins!” (You are assassins! Yes, assassins!)

Our gravel bike concurs with Steinès that riding mountains on gravel is, in fact, a fantastic idea and is happy to accept the name given by Lapize – Assassin.

Flip chips are well established in mountain biking to provide adjustable handling characteristics. We wanted to bring that idea to gravel bikes because years of building custom road bikes have taught us that confidence is very personal, so there is no single answer to ideal geometry. What’s more, gravel riding varies hugely compared to the road – having the clearance to shove in some big tires isn’t enough if you don’t tune the ride to suit.”



Another beauty from FiftyOne bikes that was exhibited at the North American Handmade Bicycle Show.

For more: FiftyOne Bikes

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