igus bearings give dimensional stabilitywhen wet
High performance bearings for world-class mountain bikes
Contrail MGN full-suspension bike from Bergamont is currently the top model of mountain bike. The bike uses innovative technology, such as butted frame tubes with various wall thicknesses as well as carbon frame components to deliver Olympic winning performances. Light polymer plain bearings from igus are also used to handle severe stresses at the dropouts of the rear suspension.
Full suspension bikes – also known as ‘fully’ – with a spring-mounted rear wheel are found to be the best by anyone who rides mountain bikes for fun and professionally. They give a far more comfortable ride and are ultimately faster, because the rider has to respond less to uneven ground. The adjustment of the suspension must be good and tight in order to provide the comfort and performance desired. Theymust be set up to absorb quick jolts well, therefore not endangering the stability of the rear suspension, and the whole system must also be ‘drive-neutral’ withmotion of the suspension not being transferred to the pedals.
The Conrail MGN model, designed by graduate engineer and product manager Thomas Marquardtat Bergamont,features supported single linkage rear suspension with a bell crank on the frame. Known as a ‘Top Fully’ in the trail bike category, they are for athletes who both win marathons and also want to enjoy cycling for fun.
Bergamont originally used ball bearings for all the bearing points of its ‘Fullys’. “At the two front pivot points, at the connection between the swingarm and the frame, we used deep groove ball bearings,”says Marquardt. “This is because the bearings here have to execute a relatively large swivel movement.”However, Bergamont has taken a new approach for the Contrail MGN and is using a plain bearing at the rear joint, on the rear axle.
There are good reasons for this, the most important being lateral stiffness. A plain bearing offers a much larger contact area than a roller bearing. “Even with very severe stresses and large lateral forces, nothing wobbles,”explains Marquardt. The plain bearings will perform very well with the high pressure loading at this bearing point. “The pressure is also very well distributed over the larger area”.
Bergamont needed advice in selecting the optimal bearing material and itstests with plain bearings on the suspension joint were supported by bearings specialist igus, who offers 10,200 items, including 35 different tribologically optimized polymer materials.The first tests were performed with iglidur G because this universal material offers the broadest range of applications at an economical cost. However, as the wheels often run through streams and puddles, and they are often cleaned after use with a garden hose or even a pressure washer, iglidur J proved to give a higher performance with greater dimensional stability when wet.Thomas Marquardt says: “These stresses are no problem for polymer plain bearings”.
The self-lubricating iglidur polymer plain bearings can expect a long and reliable service life and the feedback from bike owners was 100% positive. The torsional stiffness of the wheel is very good and the suspension responds very quickly. The very careful design of the bearing point certainly contributes to this. The innovative use of plain bearings is one of many factors that proves Bergamont’s high-tech claim for mountain bikes and trail bikes. Other design features include butted tubes with varying wall thicknesses, which contribute to the light weight of only 10.8 kg. The fork is fitted with a carbon crown; the dropouts are 3D forged.
The bikes deliver world class performance: the Olympic gold medallist in Beijing 2008, Sabine Spitz’s bike, had iglidur plain bearings in a sensitive suspension fork. The polymer components stood up to the constant impacts, edge loads, and dirt on the difficult and spectacular course at the Chinese Laoshan Velodrome. At the 2004 Athens Olympics, iglidur bearings werealso on the winners’ podium. Light and wear-resistant, they were built into the guide rollers of the derailleurs.
For further information about igus bearings visit or phone 01604 677240.
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About igus UK Ltd:
Based in Northampton in the UK, and with global headquarters in Cologne, Germany, igus is the largest producer of injection moulded polymer bearings and reinforced plastic cable carriers in the world. Product lines include industry-leading e-chain cable carriers, chainflex continuous-flex cables, iglidur plastic plain bearings, igubal spherical bearings, drylin linear bearings and guide systems. The company has 26 subsidiaries across 31 countries and employs approximately 1,800 people worldwide.
With plastic bearing experience since 1964, cable carrier experience since 1971 and continuous-flex cable since 1989, igus provides the right solution based on 80,000 products available from stock with between 1,500 and 2,500 new products introduction each year
For more information, please call igus UK directly on 01604 677240 or visit the website at: Follow us at watch our videos at and connect with us at
igus, e-chain, readychain, chainflex, iglidur, igubal, drylin and manus are registered trademarks
For further information, please contact:
igus UK Ltd, 51A Caswell Road, Brackmills, Northampton, NN4 7PW
Tel +44 (0)1604 677240 Ι Fax +44 (0)1604 677245
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Matthew Aldridge, igus UK Ltd
Tel: 01604 677240
Email:
Sarah Claridge, Technical Publicity
Tel: 07872 462646
Email:
igus UK Ltd, 51A Caswell Road, Brackmills, Northampton, NN4 7PW
Tel +44 (0)1604 677240 Ι Fax +44 (0)1604 677245
І