Review: The Bulls Urban Grinder Belt – belt drive and gravel DNA at a competitive price

​A belt drive, in-hub gears and lights integrated into the handlebars: the Bulls Urban Grinder Belt is designed for commuters who don’t want to be constantly maintaining their bike. In our test, this bike – which costs 1,299 euros and weighs 14.9 kilograms – shows what it’s capable of.

A belt-driven commuter bike: Who is the Bulls designed for?

Allow us to introduce: the commuter bike! Many of the bikes in our latest test of six all-round everyday bikes are good choices for short and medium-length journeys with a bit of luggage. They’re designed to be suitable for school, work and everything in between. However, the Bulls Urban Grinder Belt is the only bike in the test where the designers had precisely this use in mind.

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You can tell that in every detail. Bulls has completely done away with unnecessary frills to keep the price down. In return, you get a lot of solid technology for a modest 1,300 euros. Thanks to its carbon fork and disc brakes, the bike is pleasantly light, yet remains low-maintenance thanks to its belt drive and Nexus hub gears.

Frame and fork: an urban bike with gravel DNA

The chassis Bulls has released the Grinder, an all-round gravel bike (reviewed here) derived from this. Consequently, the Urban Grinder Belt rides in a sporty and responsive manner. You sit with your body slightly stretched out, which puts pressure on your hands. On the other hand, this allows you to pedal powerfully and whizz round tight bends. The wide handlebars help when standing on the pedals, should the gear feel a bit heavy at times. The riding position is clearly on the sporty side for an everyday bike – no wonder, given that the Grinder Belt also shares its frame with Bull’s gravel all-rounder.

Drivetrain: Belt and Nexus 8-speed in everyday use

The Gates belt drive runs smoothly, quietly and without the need for oil. This is handy for everyday cyclists, but an even greater advantage for commuters in office attire. The gear ratios are well chosen, offering both high gears for pedalling downhill and low gears for moderate climbs.

The belt is connected to an 8-speed Shimano Nexus rear derailleur. The gears are changed using a twist grip. This is intuitive and keeps the bike affordable. On longer rides, however, the tapered shape of the twist grip presses into the palm of the hand from the inside. This could be remedied by using the compatible Alfine trigger. Cube, for example, uses this feature of the Nexus and Alfine triggers in its sporty city bike, the Editor.

Brakes and tyres: Decelerate safely, roll smoothly

The Tektro HD-T 280 with 180-millimetre discs provide reliable stopping power. Whilst you shouldn’t expect brute braking performance, the Tektro brakes proved straightforward and quiet throughout the test period, even in wet conditions. The 45-millimetre-wide Schwalbe G-One Comp tyres roll well on tarmac and still offer sufficient grip on light gravel. A special feature: From 2027, Bulls will be switching all its tyres to Schwalbe’s new Click-Valve valve. This is intended to make it easier to use in everyday life.

Lights and luggage racks: equipped for everyday use

On the Bulls, a Fuxon Centrelight front light that complies with the StVZO is integrated into the handlebars. Its 30 lux is sufficient for city riding, and we had no problems even on the occasional dark country lane, despite its moderate brightness. Thanks to its integrated design, the light cannot be snapped off and is therefore protected against theft and vandalism. At the rear is the Fuxon RZ-60 rear light.

The luggage rack is lightweight and minimalist, matching the bike’s design. It has a small platform and can carry up to 18 kilograms. In our tests, it handled even heavy bags with ease. Thanks to the SP-Connect standard, you can easily attach your mobile phone to the stem whilst cycling. This is handy for navigation and commuting.

More everyday bikes: Find out how lightweight city bikes with motors perform in the MYBIKE test: ‘Six lightweight city e-bikes’. You can find further tests in our section City Bikes.

Comfort: The Bull’s weak point

If there’s one area where the Bulls falls short, it’s in comfort. The hard sports saddle, with only a hint of a cut-out, is a matter of personal taste and didn’t suit us particularly well. Not a major problem, though. Most commuters fit their own saddle anyway. The suspension comfort of the aluminium frame itself isn’t so easy to adjust. The Bulls definitely leans towards the firm and direct side and, even with its exemplary thin seatpost, clearly transmits bumps from the ground to the rider. However, adjusting the air pressure to around 2 bar in the 45mm gravel tyres helps to keep this effect to a minimum.

​The Grinder Belt at a glance

​The Urban Grinder Belt clearly belongs in the category City/Everyday life. It also performs well on short and medium-length trips. It is only of limited suitability for long journeys and off-road use. The seating position tends to be sporty.

• Low-maintenance thanks to the belt and in-hub gear system
• Integrated lighting
• Sporty, responsive handling

Weaknesses

• Reasonable ride comfort
• Ergonomics of the twist-grip gear selector

Technical specifications: Bulls Urban Grinder Belt