Best Mountain Bikes Under £300 UK

Yes, genuinely. The used market at this price point gives you access to brands like Trek, Specialized, GT, and Carrera — bikes that would cost significantly more new. With 7 currently listed on Cyclesite at an average of £237, there's real choice available. The key is inspecting the frame, fork, and drivetrain carefully before buying, or having a local bike shop do a pre-purchase check for around £20–£30.

Primarily age and component spec. At £160 you're looking at something like the Raleigh currently listed — older, simpler, but potentially solid if well maintained. At £300 you can get a 2024 Trek Marlin 5 Gen 2 or a 2019 Specialized, both in excellent condition with more modern geometry and better groupsets. The jump from £160 to £300 buys you meaningfully more bike, not just a shinier badge.

In the current Cyclesite listings, Carrera, Trek, GT, Specialized, and Raleigh all appear. Carrera offers the best volume and value, averaging £212 across three listings. Trek and Specialized command the full £300 but offer stronger resale if you sell on later. GT sits at £265 with the Avalanche 27.5, a well-regarded trail bike. All are reputable brands with decent parts availability.

Both work well, and the right choice depends on your height and riding style. The GT Avalanche currently listed runs 27.5-inch wheels, which are more agile and suit shorter riders or technical trail riding. The Trek Marlin uses 29-inch wheels, which roll over obstacles more easily and suit taller riders. Neither is objectively better — fit and intended terrain matter more than wheel size alone.

Start with the frame — look for cracks at the welds, not just scratches. Check the fork for smooth, leak-free movement. Test every gear and both brakes. Spin the wheels to check for buckles. If the bike has hydraulic disc brakes, squeeze the levers firmly — sponginess means air in the system. Budget £20–£40 for a new chain if needed. A spongy fork or skipping gears can cost more to fix than you saved.

Well-priced bikes in good or excellent condition in this range typically sell within two to three weeks. With only 7 listed currently, there isn't a huge pool of stock, so genuinely good examples — like the 2021 Carrera Hellcat at £200 in good condition — tend not to hang around. Setting up alerts and moving quickly on listings that tick your boxes is a sensible approach.

Yes, though you'll want to focus on bikes with proper suspension forks (80–100mm travel), disc brakes, and a frame geometry designed for trail use rather than hybrid or leisure riding. The GT Avalanche 27.5 at £265 and the Trek Marlin 5 at £300 are both trail-capable bikes. Carrera's Hellcat and Vengeance are also trail-oriented designs. Avoid anything described as a hybrid or trekking bike if you plan to ride singletrack regularly.

Generally, newer wins if condition is equal — fewer unknowns, more modern geometry, and longer usable life ahead of it. The 2024 Trek Marlin 5 Gen 2 at £300 makes a strong case on that basis. But a 2021 Carrera Hellcat at £200 in good condition can represent better value than a 2019 bike at £300 in uncertain condition. Condition and service history should always be weighted alongside year and spec.