Decathlon Triban RC 120 Review: How Much Road Bike Does £350 Buy?

Introduction

The entry-level road bike market has quietly become one of the best value corners of cycling. A £350 machine no longer has to feel like a compromise, and the Decathlon Triban RC 120 is a clear example of how far that money now stretches. Listed at £400 with £50 off, it arrives with an aluminium frame, a carbon fork, an eight-speed drivetrain and mounting points that usually belong on considerably more expensive bikes.

This guide covers what the RC 120 does well, where the compromises show up, and who will get the most out of it.

Who this product is for

The RC 120 is aimed squarely at riders buying their first road bike. The frame uses endurance geometry, which keeps the riding position more upright and relaxed than a race bike. That matters at this price point: newer riders tend to value comfort and confidence over aerodynamic efficiency, and the RC 120 is built around that priority.

It also works as a practical commuter or winter bike. The frame accepts mudguards and a rear rack, and the ride position is easy to live with on shorter, more casual outings. Anyone who already rides a lot and wants a second bike for bad weather will find the same appeal.

Main strengths

The headline strength is simply how much bike £350 buys. The specification reads like something from a higher price bracket.

Ride quality and shifting

The aluminium frame is paired with a carbon fork, which is a genuine surprise at this price. The result is a bike that feels lively and fun to ride rather than merely functional, with a gear range that covers a wide spread of terrain comfortably.

The Microshift R8 eight-speed groupset is the standout component. Shifting is smooth and precise, and the system can move up to three gears at once in one direction while dropping a single gear at a time in the other. The front derailleur offers two trim positions on each chainring, which lets you nudge the cage slightly left or right to silence chain rub without making a full shift. The levers carry two buttons on the same side, and both can be reached from the drops, although the upshift button sits noticeably high, which takes some adjustment.

Practicality and everyday use

Mudguard and rack mounts are included front and rear, which is rare on a bike at this price and turns the RC 120 into a viable year-round commuter.

Tire clearance is another welcome detail. The bike ships with 28mm Triban tires that feel grippy on the road, and the frame and wheels look capable of accepting at least 32mm rubber. Fitting wider tires at lower pressure is a sensible upgrade on an aluminium frame, since it takes some of the buzz out of rougher surfaces.

Things to consider before buying

Some of the cost savings are visible in the details, and it is worth knowing about them before you commit.

The bike ships with lights, but they are basic units with limited output. They will keep you technically legal, yet they do not add much in the way of real road presence, so most riders will want to replace them.

There is also no replaceable rear derailleur hanger. On most bikes a soft metal hanger bolts to the frame and bends in a crash, protecting the frame itself. Here the derailleur mounts directly, so a hard impact on the drive side can damage the aluminium frame instead. Aluminium can sometimes be bent back, but doing so weakens it over time.

A small rubber collar on one side of the wheel can develop a squeak after the first ride. It is an easy fix, but it is the kind of minor issue that appears on budget builds.

Finally, the rear brake cable is routed the long way around the frame rather than straight into the stop on the left side. It works fine, it simply uses more cable than necessary.

Sizing and geometry

Sizing deserves particular attention. The medium frame has a 55cm top tube, which is long enough that several other brands would label it a large. Bike sizing is not consistent across the industry, and choosing a medium because you wear a medium T-shirt can easily land you on a frame that is too big.

Decathlon publishes geometry charts for the RC 120, and comparing the reach and top tube figures against a bike you already know is the safest approach. The 40cm handlebars on the medium are matched to frame size, with wider bars on larger frames and narrower bars on smaller ones. As with any new bike, it is worth checking that the bars are straight before your first ride.

Wheels and long-term maintenance

The wheels are the weakest part of the package. They use unbranded rims with an aluminium braking surface and cup and cone bearings that are not sealed. In dry, clean conditions they can last reasonably well, but regular wet-weather riding or daily commuting will shorten their life considerably.

Because the bearings are not sealed, they can be serviced rather than replaced. Having a shop fit new ball bearings costs roughly £20 to £30 per wheel, and staying on top of that schedule prevents damage to the bearing races. A better wheelset is the single most effective upgrade for this bike, and it transforms how the whole machine feels.

The saddle is a B Twin own-brand unit. It is fine for shorter rides, but becomes noticeable after about half an hour, so riders planning longer distances should budget for a swap.

Buying advice

At £350, the Triban RC 120 delivers a genuinely impressive package: an aluminium frame, a carbon fork, a reliable eight-speed drivetrain and mounts for mudguards and a rack. The relaxed geometry makes it forgiving for new riders, and the gearing is broad enough to handle mixed terrain without complaint.

It is worth being realistic about what you are buying. This is a bike that is excellent for an hour of spirited riding, a daily commute or a first season of road cycling. It is less suited to five-hour endurance rides, where the long top tube and firm aluminium frame start to tell.

Decathlon includes a free service within the first three months of purchase, which is a good opportunity to have the bike checked over and the wheel bearings assessed. Budget for a saddle if you plan long rides, and treat a wheelset upgrade as the first meaningful improvement. Even with those additions, the total outlay stays modest for what the bike offers.

Conclusion

The Triban RC 120 shows how competitive entry-level road bikes have become. It is not perfect, and the wheels, saddle and derailleur hanger design all reflect its price, but the fundamentals are right where they matter: the frame, the fork, the gearing and the mounting points. For a new rider or anyone after an affordable commuter, it is a purchase that is easy to feel good about.