Trek have slimmed down their mountain bike range for 2025. Some models have gone entirely, and others have been reduced to limited options. There are still plenty of bikes to choose from, but with less overlap between some of the models.
All Trek bikes are unisex. On virtually all Trek bikes you will get different wheel sizes depending on the frame size of the bike. Typically XSmall and Small bikes will come with 27.5” wheels, while bikes from Medium and up will have a 29” wheel.
On some bikes, such as the Marlin, the smallest frames will also come with a curved top tube to give increased standover height.
This bike has disappeared from the Trek mountain bike range for 2025. To fill the gap the Marlin range has been stretched, up and the Procaliber has been stretched down, to cover the same price points.
The Marlin is often claimed to be the best-selling mountain bike in the world. It has been one of our top sellers for the last few years. This is a general-purpose mountain bike that can be used for commuting and general leisure rides as well as being ridden off-road. If you are planning on doing regular off-road rides we do recommend going for the 5, 6 or 7. The 4 is a good general-purpose bike but the cable operated brakes don’t perform great in wet and muddy conditions.
There are 2 different frames in use on the Marlin. The entry level Marlin 4 comes with a Gen 2 frame. The 5, 6 and 7 come with a Gen 3 frame (there is no Marlin 8 for 2025). The updated frame has more trail focussed geometry for better handling off-road.
The entry level Marlin 4 comes with mechanical cable operated disc brakes, whereas the rest of the range has hydraulic brakes. The Marlin 4 also comes with a double ring chainset on the front whereas the rest of the bikes have a single 1x chainset.
There are bigger steps in the Marlin range this year. Whereas each model used to be around £100 more than the one below the gaps are now up to £250 between models. On the top level Marlin 7 this means you can now get a Rockshox air fork with a lockout and 12 speed SRAM Eagle gearing.
The Trek Roscoe range has shrunk dramatically for 2025. Where there used to be a Roscoe, 6, 7, 8 and 9 there is now just a Roscoe 7. Where the Marlin is designed as a general use bike the Roscoe is designed as a playful trail bike for mountain bikers who want to push their skills. It comes with a 140mm front suspension fork (compare to 100mm on the Marlin) and beefy 2.6” wide tyres. The tried and tested Shimano Deore gearing is pretty bombproof and you get a TranzX dropper post as well.
Filling the gap where the old X-Caliber model used to sit are the Procaliber 6 and 8. These bikes are a halfway house between the top end Marlin and the Roscoe. They come with a 120mm travel fork and are designed for fast cross country mountain bike rides.
The Procaliber 6 and 8 are built around an Alpha Platinum Aluminium frame. Both comes with 120mm Rockshox forks and 12 speed Shimano gearing. On the 8 this is a mix of SLX and XT gearing compared to Deore on the 6.
This is a similar style of bike to the Precaliber 6 and 8 but it comes with a carbon fibre frame, rather than aluminium. This makes the bike lighter and adds in some extra compliance to make it more comfortable on long rides. The frame comes with IsoBow vibration-damping tech to smooth out chatter.
The carbon version of the Procaliber is more race focussed that the aluminium one. If you are looking to line up at XC or marathon races this is the bike to go for.
The Fuel EX is a do it all trail bike that comes with 150mm suspension travel on the front and 140mm at the back. That’s enough to have fun on the most challenging trails while still being efficient enough to pedal back to the top. The Fuel EX 5 and 8 come with aluminium frames while the 9.8 and above have carbon frames. At the time of writing the carbon bikes are all being built to order so you can expect lead times of anything from 1 week to 3 months on them. The aluminium bikes are standard pre-built bikes so are available more quickly.
The Top Fuel is the bike that most people in the UK should be riding. It’s a ‘down country’ bike that can handle a variety of trails, from smooth cross-country to more rugged all-mountain. With 130mm and 120mm of suspension travel it will rip up climbs while still being able to handle rough descents and technical sections. It’s efficient enough for all day riding, adventure racing or quick laps on your favourite trails.
Like the Fuel EX, the Top Fuel 5, 8 and 9 comes with an aluminium frame. The Top Fuel 9.8 and above come with carbon fibre frames.
This bike has been removed from the range for 2025. The nearest equivalent is now the Trek Slash.
The Slash is Trek’s endurance bike. It can be used both for endurance racing and also for bike park weekends, trips to the alps and other use where going downhill is your focus but you do still need the ability to pedal back up.
The most eye-catching feature of the Slash is the high pivot suspension design. This uses extra pulleys to keep the chain in control as the rear swing arm moves. This makes for more efficient pedalling.
The Slash has 170mm of suspension travel front and rear and a mullet setup (27.5” wheel at the back and 29” at the front).
These are Trek’s specialist XC and DH race bikes. They are not bikes we tend to stock at Cycles UK but we can order them in.
The Supercaliber is Trek’s pro level XC race bike. It comes with 110mm of travel at the front and 80mm at the rear through a rear shock that sits partly inside the top tube.
The Session is a dedicated downhill race bike. It comes with a high pivot design that’s similar to the Slash and 200mm of suspension front and rear.