FiftyOne Bikes Reviews 

My new Fiftyone Sika is better than I expected. The ride is so comfortable but the performance is even better. The exact frame I've been looking for. With SRAM Force and 35mm tires I can enjoy this bike all day. I'm a 64 year old athlete and the Sika is great for me!

I had the pleasure of riding an FiftyOne Assassin across the trails of the Dublin mountains last week with Aidan from the 51 team. I couldn’t believe how light and nimble the bike felt on the road and at the same time how easily it handled the trails and fast gravel descents. With two sets of wheels these machines would excellently cover your off-road, touring and weekend spin needs. A great day out on a great machine.

Recently bought a Fifty One Assassin. The experience of buying from
Fifty One is incredible. Really personal, Aidan took loads of time showing me the bike and showing me around. The end product is great also, the Assassin is great to ride and feels a bit special due to the experience of buying from a great boutique brand.

If you are on the fence about investing in a FiftyOne Assassin, let this be your sign to absolutely go for it. I can say without a shadow of a doubt that this is one of the greatest, most capable bicycles I have ever ridden in my entire life.
From the tarmac to the technical gravel trails, the Assassin behaves like an absolute dream. The geometry is a masterclass in engineering—it is incredibly fast, agile, and responsive, yet it maintains a grounded stability that gives you ultimate confidence on rough terrain. The ride quality is buttery smooth, absorbing the chatter while delivering pure, unadulterated power transfer every time you step on the pedals. It doesn't just ride well; it makes you want to ride further and faster. It is a stunning piece of Irish craftsmanship that stands head and shoulders above the mass-produced competition.

World-Class Service from a World-Class Team

An elite bike deserves elite customer service, and the team at FiftyOne completely blew me away. From day one, the staff treated me less like a customer and more like a part of the family. Their passion, expertise, and attention to detail are unmatched. They took the time to understand exactly what I wanted, guided me through the process with absolute patience, and ensured the bike was dialed in perfectly for me.

The Verdict: You aren't just buying a bike here; you are getting a bespoke experience backed by a team that genuinely cares about your ride.

Thank you to the phenomenal staff at FiftyOne for creating an absolute masterpiece and providing service that is second to none.

If you want the best gravel experience on the market, look no further than the Assassin!

Flawless from ordering to delivery. Top company selling top products. FiftyOne Bikes are all they are hyped up to be.

Fantastic bikes and a lovely bunch of people to deal with. Would highly recommend.

51 Assassin/Custom Painted.... got my custom painted Assassin directly from 51 Bikes just over a year ago. Great guys, very easy to deal with. Genuinely, this is the most comfortable, versatile bike I have ever owned. I ve done club gravel rides, I've raced it and I've even cycled across the entire Pyrenees with luggage on this machine. Just a quick flip of the flip chips and your Assissin goes from being a reasonably aggressive gravel race bike to an extremely capable touring rig. Plenty of mounting points on the bike as well. Ultimately the Assassin feels like a quality product, leaving you with a great sense of reliability. Highly recommended. Carbon Ken

The Buying Experience & Customer Service
Dealing directly with Aidan Duff and the FiftyOne team was absolute class. The direct communication via email was exceptional, hashing out every single detail from component spec to tailoring the frame geometry around my professional bike fit data. It’s rare to get this level of personalized, premium service from a bike manufacturer, and it makes the entire build process incredibly special.

Frame & Ride Quality After 2,000 km
I’ve put a solid 2,000 kilometres on the Sika across all weather conditions and tarmac qualities to give an objective verdict. The carbon frame is a masterpiece. The rear triangle has a supernatural ability to soak up micro-vibrations and take the sting out of harsh potholes.

Despite this plush compliance, it doesn’t sacrifice an ounce of performance. It offers the snappy kick and agility of a thoroughbred roadie. The bike reacts to the slightest input, handling like a dream through tight switchbacks while oozing rock-solid stability on fast descents. How FiftyOne married razor-sharp handling with magic-carpet ride comfort is a technological triumph.

Top-Tier Hardware & Performance
The Cockpit: The proprietary integrated carbon bar and stem combo is brilliant. The subtle flare at the drops gives massive confidence when bombing downhills, and the engineered vertical flex saves your hands from road chatter without losing torsional stiffness when dancing out of the saddle.

The Drivetrain & Weight: Built up with a Campagnolo Super Record X 1x13 drivetrain, the bike tips the scales at a featherlight 6.9 kg. It is an absolute weapon on the climbs—there is zero sluggishness.

Tyre Clearance & Versatility: I run 34 mm tyres on wide carbon hoops, and real-world testing proves there is zero measurable speed or aero penalty compared to narrower setups. The footprint delivers massive cornering grip. Furthermore, the frame clearance is generous enough to fit 40 mm gravel rubber if you ever want to swap wheelsets, highlighting the frame's incredible versatility.

Verdict
If you are looking for an uncompromising, bone-rattling pro-peloton sprint bike to shave milliseconds in a bunch finish, look elsewhere.

But if you want a fast, deeply responsive, high-performance machine for epic, all-day spins without coming home completely banjaxed by a stiff frame, the FiftyOne Sika is arguably the best, most mature whip on the market. A massive chapeau to Aidan and his engineering team—they have done a stellar job.

I have a FiftyOne Sika, built by Bike Science in Gloucestershire. First off, I absolutely love this bike. I was originally looking at the big brands for a new bike (Specialized Tarmac, Bianchi, Giant) but Andy Sexton of Bike Science convinced me to go for the Sika and have a custom build. He was spot on. I cannot be happier with the bike. Obviously a custom build means it fits like a glove, but the bike rides like nothing I’ve ridden before. I’ve never set so many Strava PR’s 😂. It’s the perfect bike for a Sunday club warrior. Seriously fast, but comfortable. Designed for “normal riders” not the pro’s. It also turns a lot of heads. I’m asked so many questions. It really is an amazing bike and I am so glad to have gone for it. When it comes to replacing my gravel bike, I will be heading straight back to FiftyOne. Keep up the great work.

5 * product , 5* service