Cema Bearing 6805 25x37x7 mm - Wheels & bottom bracket

Cema is among the leading manufacturers of bicycle bearings, and is known for delivering uncompromising quality for both competition and everyday use. With an extensive range of both standard and special dimensions, Cema covers virtually all needs – from bottom brackets and wheel hubs to pulley wheels and pedals. The bearings are designed with a focus on low friction, high precision and maximum durability. This makes them ideal for riders who want to utilize every watt and optimize their equipment down to the smallest detail. Cema offers both steel bearings and hybrid ceramic bearings, and the range is aimed at all levels – from ambitious exercisers to professional athletes. With bearings from Cema, you get a clear improvement in rolling resistance and a more direct and efficient feel throughout the transmission. The result is not just measurable – it can be felt on the road.

Cema produces two main types of bearings: precision steel bearings and hybrid ceramic bearings. Steel bearings are engineered to extremely tight tolerances and are perfect for training wheels, gravel, winter riding and other demanding applications where durability and low maintenance are key. Ceramic bearings combine steel raceways with ceramic balls, significantly reducing friction and providing a significant improvement in freewheeling and rotational resistance. These bearings are often used in wheels and pulley wheels for competitive use where marginal gains and wattage savings are crucial. Cema uses sealed systems and lubricants that match the type of bearing and application they are designed for. This means that the products perform optimally – whether it’s long training sessions in bad weather or time trials in dry, hot conditions. The combination of material selection, precision and reliability has made Cema a preferred choice among both bike mechanics and riders who don’t compromise.

Proper maintenance is the key to getting the most out of Cema bearings. Ceramic bearings in particular require regular care to maintain their smooth-running properties. For optimal service life, the bearings should be cleaned and lubricated at regular intervals – depending on use and conditions. It is recommended to avoid high-pressure cleaning directly on the components, as this can force moisture and dirt behind the seals. When cleaning, the seals are carefully removed, after which the bearings can be cleaned with a mild degreaser and dried thoroughly. After drying, apply an appropriate amount of special grease or light oil, depending on whether the purpose is daily operation or a race-optimized setup. For winter use and wet conditions, a slightly thicker lubrication is recommended, which provides better protection against moisture and dirt. The rotation of the bearings should be checked regularly – any noise, play or roughness is a sign that service or replacement may be necessary. In addition, correct installation is essential. Using the right tools and following torque recommendations ensures that the bearings are not pressed in crookedly or damaged. With proper care, Cema bearings can deliver long-lasting performance, minimal friction, and a noticeable difference in the overall feel of the bike.