The Gazelle Curb belongs to the urban e-bike category. Unlike comfort-oriented city bikes with suspension forks, wide luggage racks, and an upright seating position, it pursues a minimalist approach. The riding posture is active, the stem is non-adjustable, and the aluminum fork is unsprung. As a result, the bike is aimed at riders who prefer a direct riding feel and primarily travel quickly on city streets.

The frame is offered as a high-step and low-step. High-step refers to the classic frame shape with a higher top tube. The low-step frame makes mounting easier and is practical if you have to stop frequently in dense city traffic. Both styles are available in sizes S, M, L, and XL. The corresponding frame heights range from 45 to 60 centimeters.

Weighing approximately 20 to 21 kilograms without the battery, the Curb is lighter than many fully equipped electric city bikes. For an apartment without an elevator, however, it remains a bicycle whose transport over several floors requires some effort. The removable battery makes carrying it somewhat easier. Before purchasing, a test ride with the chosen frame style and size is recommended, because the active seating position offers less room for subsequent adjustments than an adjustable comfort cockpit.

The 27.5-inch wheels are equipped with 50-584 tires. This combination keeps the bike compact and gives the tires enough volume to absorb smaller bumps. There is no suspension. On smooth asphalt, this setup supports direct handling. Anyone who regularly rides over rough pavement, damaged bike paths, or high curbs should check during a test ride whether the non-suspended setup suits their personal comfort requirements.

Standard front and rear carriers are not part of the concept. However, Gazelle offers matching carriers as accessories. This maintains the bike's slim silhouette and gives you the choice of whether to use the Curb as a lightweight commuter bike or with additional transport options. For daily groceries or a work bag, a retrofitted rear carrier is usually more practical than a backpack.

The Bosch Hub Line is located in the rear wheel hub and provides assistance up to a speed of 25 km/h. Its maximum torque is 45 Nm. This makes it tailored for city traffic, flat terrain, and moderate inclines. Those who frequently start from a standstill at traffic lights will feel a noticeable push from the rear wheel. For long distances in steep terrain, mid-drive motors with higher torque are generally more suitable.

A rear hub motor offers a different riding experience compared to a mid-drive motor. With a mid-drive motor, assistance is generated at the bottom bracket and transmitted to the rear wheel via a chain or belt. The Hub Line drives the rear wheel directly. When accelerating, this can feel as if the bicycle is being pushed from behind. Since the motor power is not transmitted through the mechanical drivetrain, it does not place additional stress on the chain or belt.

The position in the rear wheel hub contributes to a sleek appearance, but it has practical consequences. In addition to the rim, tire, and brake disc, the rear wheel also contains the motor. Removing it is therefore more complex than with a standard rear wheel. For a tire change or repair on the rear wheel, it may be advisable to have the work done at a specialist workshop. Regularly checking tire pressure and tread is therefore worthwhile before long rides.

The motor is integrated into the Bosch Smart System. It is controlled via the System Controller in the frame and the Mini Remote on the handlebars. Four assistance levels are available:

• Eco provides economical assistance and is suitable for longer distances, flat cycle paths, and rides where time is not a major factor.
• Tour delivers more thrust and is suited to typical commutes with multiple stops and varying route profiles.
• Auto adapts the assistance to the riding situation. This is practical when open sections, intersections, and slight inclines frequently alternate.
• Turbo provides the strongest assistance. This mode facilitates quick starts and short climbs, but consumes significantly more energy.

For a short commute through flat terrain, Eco is often sufficient. If you frequently ride with luggage or want to quickly merge into flowing traffic, Tour and Auto are more suitable. Turbo is intended primarily for specific situations. Those who use it continuously will need to charge the battery correspondingly sooner.

Compared to a powerful mid-drive motor, the Bosch Hub Line is less designed for steep climbs and high payloads. Its 45 Nm is better suited to short to medium distances in urban areas. This applies especially to the Curb C1, whose single gear does not allow for adjustment of the gear ratio. In a flat city, this concept is straightforward. For frequent inclines, the Curb T9 with nine gears offers more control over cadence.

The Gazelle Curb C1 is aimed at riders who want to shift gears as little as possible and prefer a clean, quiet drivetrain. The Gates belt requires no chain oil. As a result, when handled correctly, it barely leaves any oily stains on trouser legs, hands, or the floor. This is useful if the bicycle is kept in an apartment, in an office, or in a narrow hallway.

However, a belt is not completely maintenance-free. Its tension must be correct, and dirt should be removed with water. Repairs or replacements should be left to a workshop with experience in belt drives. In everyday use, however, the maintenance required is still lower than that of an exposed chain.

The limitation of the C1 lies in its single gear ratio. You cannot shift into an easier gear for a steep climb, nor can you select a heavier gear for faster riding. The electric motor partially compensates for this limitation. This works well on flat paths and when stopping frequently. In hilly urban areas, however, the fixed gear ratio can force an unsuitable pedaling cadence.

The Gazelle Curb T9 offers nine gears and can be adjusted more precisely to speed, incline, and load. You can shift down before a climb and ride at a higher cadence. On open sections, a higher gear ratio is available. This also helps if the battery is empty and you have to continue without motor assistance.

The derailleur gear system requires more maintenance. After riding in the rain and during the winter, the chain, cassette, and rear derailleur should be cleaned regularly. Lubrication and wear checks are also part of this. Those who commute in all weather conditions must take this effort into account when choosing a model.

If your usual routes are largely flat and you are looking for simple operation, the Curb C1 is a better fit. If you ride over bridges, longer inclines, or highly varied routes, the Curb T9 offers more reserves. The higher maintenance requirement of the derailleur system is then the price for the more flexible gear range.

These values are reference figures and not guaranteed distances. In real-world city traffic, frequent starting, low temperatures, headwinds, inclines, and low tire pressure reduce the range. Rider weight, luggage, and the selected assistance level also have an impact. In winter, the usable capacity can be noticeably lower than at mild temperatures.

For a commute of ten kilometers each way, the battery often provides enough reserve for two or more days. Anyone riding permanently in turbo mode should charge daily or after every second trip. When using Eco or Tour modes primarily, longer charging intervals are possible.

The Bosch Compact Charger provides 2 A. A full charge takes approximately five hours and 30 minutes. You can charge the battery on the bike or remove it from the down tube. This is particularly helpful for renters who do not have a power outlet at their bike parking space. If the battery is charged indoors, it should be kept in a dry place and not positioned directly next to a strong heat source.

Allow for a safety margin on longer routes. If the planned route is already near the maximum range, you should arrange for a charging opportunity or select a more economical mode. Consumption is usually higher in stop-and-go traffic than during steady riding on an open bike path.

The cockpit of the Gazelle Curb does away with a large, traditional display. The Bosch System Controller shows basic information via LEDs. Using the Mini Remote on the handlebar, you can change the support level without moving your hand far from the grip. This solution keeps the handlebar uncluttered and reduces the number of visible components.

A smartphone can be used for navigation and detailed ride data. The cockpit has an interface for mounts from SP Connect or Quad Lock. Before purchasing, you should check which mount is compatible with your smartphone and the protective case you use. A secure mechanical hold is more important on cobblestones and poor bike paths than the ability to mount it quickly.

Ride data such as speed and remaining range can be accessed via the Gazelle app. This allows the smartphone to replace a separate color display. Those who do not wish to use their phone during every ride can still operate the motor via the controller and Mini Remote. The bike therefore remains ready for use even without a mounted smartphone.

The standard minimalist transport concept is suitable for commuters who only carry a small backpack. For shopping, a briefcase, or longer everyday rides, a luggage rack is worth considering. Before ordering, check which accessories are approved for the respective Curb model and what maximum payload the rack allows.

Further equipment includes:

• Hydraulic Shimano MT200 disc brakes with 160 mm brake discs at the front and rear
• Supernova Starstream Mini front light powered by the e-bike battery
• Supernova TL3Z rear light, also connected to the main battery
• Ergonomic Herrmans Click grips with cushioning properties
• Selle Royal On Moderate saddle for an active riding position
• Rigid aluminum fork without low-maintenance suspension
• AXA frame lock with connection option for an additional plug-in chain
• Sturdy rear kickstand from Ursus
• Optionally available front and rear racks

The hydraulic disc brakes can be modulated with comparatively little hand force and also function on wet roads. As with every disc brake, pads and brake discs must be checked regularly. Grinding noises, a significantly changed pressure point, or weak braking performance should be checked promptly.

The permanently installed lighting is more practical in everyday use than separate battery-powered lights. It is switched on via the e-bike system and cannot be accidentally left at home. The AXA frame lock secures the rear wheel for short stops. For longer parking periods, a frame lock alone is not enough. An additional lock should connect the frame and bike rack to each other.