Monthly Archives: November 2018

  1. Aero Bike wheel test... The fallout

    Those of you who are avid viewers of a number of Internet forums will have noted that some results from my bike wheel wind tunnel testing have been contested and criticized. The ultimate result was I ended up getting banned from weightweenies for a week for calling Tom Anhalt of bike blather a spec of shite on the anus of humanity and a letter went from Flo Cycling to my HR department to ask for me to get the sack.

    One of the advantages to not being in the bike industry full time is I don't really give two hoots about brand perception and I'm more than happy to tell someone where to poke it when they are talking from their rear end.

    The Background

    This story starts off with an innocent enough beginning. One of my colleagues was doing an IronMan race and needed the fastest wheels. So some testing was performed. The difference was as a group of aerospace engineers, we probably have a better understanding of airflow than bike companies whose primary aim is to

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  2. Ceramic Bearings vs Steel Bearings... An Engineering Opinion

    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.

    Bearing Terminology

    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 nitride or equivalent. Steel Bearings are commodity items that are composed of hardened steel balls and a steel inner and outer race. Geometrically, the contact points, inner and outer dimensions and thickness between steel and ceramic bearings is the same so they are interchangeable. The only real big noticeable difference between the two is the bearing cl

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  3. Appearance on GCN

    I was recently invited to appear on the GCN Tech YouTube Channel. You can see my performance below. I had a great day there, it was fantastic!

    Some of the content was edited out, the original recording was probably in excess of 1.5 hours so I will make a video to cover some of the questions that had not been answered as thoroughly as some of the commenters wanted

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  4. Bicycle Wheel Aerodynamics, Which one is fastest!

    In terms of drag caused by a bicycle rider, the biggest loss is caused by the rider themselves followed by the wheels and frame.

    The drag caused by wheels is significant because of two fundamental reasons. The first is they hit the air first as they are the most forward part of the bike and second because they are rotating. The effective air speed at the top of a wheel/tyre is double the indicated speed of the bike.

    In the bike industry, wheel aerodynamic testing has generally been conducted by two groups of people - Wheel manufacturers and journalists. Wheel manufacturers will usually adjust tests to make their particular wheels look more favourable than their competitors in testing. This is usually achieved by a combination of adjusting speeds and angles. The reality is this type of test is not impartial.

    Journalists on the other hand tend to visit their local university and ask some clever boffin to conduct their testing for them and give them the

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