NTN Archives - Hambini Engineering

Bottom Bracket Pressfit and Creaking, an Engineering Analysis

If you are reading this you will have probably already come across the numerous posts by various individuals in Internet forums across the web. The issue of creaking bottom brackets has been blamed on the introduction of pressfit and directfit bottom bracket standards, where bearings either push directly into the bike frame or push into cups which are then pushed into the bike frame. General guidance varies from taking everything out and regreasing it to installing with extreme measures such as epoxy resin.…

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11/12/2019

Bearings / Wheels

Testing to Find the Fastest Bicycle Wheel Hubs

The aerodynamic performance of wheels often grabs the headlines and the marketing budget but the reality is the hubs and the bearings within them will have more of a performance differential for the average cyclist. As an example, the power differential between wheels of an equivalent depth at speeds of less than 35km/h will only be 1-2W, the difference in bearing friction can easily exceed that. Wheel hubs and freehubs account for around 60% of the rotational friction in a bicycle drivetrain. The…

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11/12/2019

Bearings / Bottom Brackets / Wheels

Ceramic Bearings vs Steel Bearings… An Engineering Analysis

One of the most controversial topics in the cycling industry is with regards the topic of Ceramic bearings and whether they do or do not reduce friction dramatically in riding. This article will address some of the concerns and topics associated with this debate and quantify the numbers. Internal Bearing construction - Ceramic bearings are not 100% ceramic Ceramic bearings are in actual fact hybrid. They use ceramic balls and usually a steel inner and outer race. The ceramic balls are often silicon…

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11/12/2019