Less weight with special plain bearings in the suspension fork

Profile

Magura suspension fork and mountain bike in an off-road test.

What was needed: Special plain bearings for the guidance of the immersion tubes
Requirements: wear resistance, very good response behaviour, cost-effective, low weight
Area of application: Bicycle industry, mountain bike technology

The Swabian company Magura is one of the world's leading manufacturers of brake and suspension technology, making it one of Germany's flagship companies in the bicycle industry. Also in the portfolio: Cross-country and marathon suspension forks, which have to offer a high degree of robustness, consistently good response behaviour and minimal weight on long, rocky trails.

Problem

For the XC fork "Magura Durin Race" with 100 millimetres of travel (MD 100R), the developers were looking for a way to reduce manufacturing costs and weight without compromising performance. The guidance of the immersion tubes, usually solved by means of metallic bearings, offered the greatest potential for optimisation. The challenge was to find a lightweight, oil-resistant component that could withstand impact and edge loads and ensure very good response behaviour without a stick-slip effect.

Solution

The solution was found in dialogue with igus®: plain bearings made of iglidur® J-plastic in a special shape. They are around five times lighter than metallic bearings of the same dimensions. The iglidur ® J-material is ideal for this application, it is media-resistant, resistant to edge pressure, impacts and shocks and has a very low stick-slip tendency. Grooves on the inside ensure that the fork oil can be transported from the oil sump to the upper bearing. And the performance? At the 26.7 km Olympic mountain bike race in Beijing in 2008, the bearings passed the practical test with ease: Sabine Spitz mastered the tough course on her bike equipped with the Magura fork with a large lead and won the gold medal.