Test Bulls Trail Grinder: The 2024 gravel bike from the Cologne off-road brand surprises with an air suspension fork and new Shimano GRX 1×12 at an extremely low price. Function and driving characteristics inspire; Retrofitting tip is a light 650B wheelset, for which there is definitely still money left.
The close relationship between gravel bikes and mountain bikes is discussed again and again. Even in the early 1980s, it was not uncommon in the still young scene to plow through the terrain with wide 26-inch tires and racing handlebars - first with rigid forks and bar-end shifters, then briefly with more modern technology such as the earliest Shimano STI levers. Around 1990, John Tomac was successful in the MTB World Cup with racing handlebars, disc bikes and 25 mm suspension forks, but then the exotic bikes were over.
Bulls Trail Grinder: New model with Shimano GRX RX820 “Unbeatable”
Now gravel bikes are bringing back the wild times - especially models that are more MTB-oriented. And a bike that can be considered exemplary in this regard is the Trail Grinder from the Cologne MTB brand Bulls. The model has been on the market for a few years and got a new frame in 2021, which has a lot of impressive details. First of all, what should be highlighted is the relaxed seat geometry, which is closer to a trail MTB than a racing bike or cyclocrosser. This will appeal to many people who have not had much to do with the racing wheel before. Because now you can be pleased to discover that this does not always have to be accompanied by a stretched sitting posture. The short handlebar stem, which is standard on modern MTBs, also contributes to this.
Another plus point of the Bull is the numerous mounting points, which also include four screws under the top tube - for attaching a tension strap under which you can clip your rain jacket, for example. The routing of the brake line and gear cable through the chainstays and down tube is also pleasing.
Frame with nice details and air suspension fork
However, what sets the Bulls apart from the masses of gravel bikes is its air suspension fork with 40 mm of travel. This won't seem like much to mountain bikers, but this suspension travel has become standard on gravel bikes - it's large enough to effectively absorb road shocks and doesn't lead to major changes in geometry. If the fork is blocked, the Trail Grinder feels like a conventional gravel bike and can be moved without loss when pedaling or on asphalt.
Bulls' road bike-based wheels come in the tried-and-tested 622 format. You might think that's a shame, since the tire width in this case is limited to 45 mm - you can clearly see how narrow the gap between the seat tube and the rear tire is. However, you can of course retrofit a 650B wheelset (i.e. 27,5 inches), which you can then run with 50 mm tires, which makes sense for tougher off-road use. But do you want to buy a new set of wheels to go with your new bike?
Extremely attractive price
With the Bulls Trail Grinder it does - for three reasons: Firstly, the wheelset on the test bike weighs over four kilos - so it's worth starting here. On the other hand, Bulls is asking just 1.999 euros for this bike, so there may be some budget left over for new wheels. And thirdly, the bike is sensationally affordable, especially since Bulls is one of the very first manufacturers to install the new Shimano GRX RX820 “Unbeatable” - an improved version of the proven components that now offer twelve instead of eleven gears and an extremely wide range of gear ratios with a 10-45 cassette can, which means that the GRX is catching up with the Italian and American competition.
Functionally, the GRX was already at such a high level that the new group practically does not differ from the eleven-speed version. However, the architecture of the levers has been optimized so that the RX820 fits better with gravel handlebars with a strong angle (“flare”). The rear derailleur has undergone a significant visual change, with a smoother surface and a “Shadow RD+” stabilizer designed to prevent chain slap even more effectively on rough roads. Which is very helpful, because despite the effective shock absorption of the Suntour fork, the Bulls, as an aluminum hardtail, gets shaken up a lot at the back when you hit the trails. The bike appeals with its handy steering, which allows precise steering even at low speeds. The Trails Grinder is not a real mountain bike, even with a suspension fork, and some obstacles that you simply roll over on a long-travel MTB are better able to circumnavigate with a gravel bike.
Wishes, suggestions, criticism? The only thing missing from the Bulls to perfection is a dropper post, as is installed on some trail gravel bikes. The new Shimano GRX allows this option; Of course, the attractive price would then not be entirely maintainable. But even so, the Bulls Trail Grinder is an extremely interesting gravel bike for anyone who wants to venture into difficult terrain with racing handlebars - similar to almost 40 years ago, but with much, much better material.