Hour Record Broken! Heavy Wheel?

http://www.cyclingnews.com/news/?id=2005/jul05/jul21news

Edited by Jeff Jones and Shane Stokes Boardman reacts to new hour record

*By Shane Stokes *

Although he admits to being disappointed to lose his athlete’s hour record, Chris Boardman has congratulated the Czech rider Ondrej Sosenka for his efforts. The Czech rider recorded a distance of 49.7 km in Moscow yesterday afternoon, improving the old standard by 259 metres. The record has yet to be ratified by the UCI.

“Records will always be broken,” Boardman told Cyclingnews today. “Just take a look at Lance Armstrong’s achievements as an example. So I never expected this one to be an exception to that rule. Yes, it is always a little sad to see something that you worked for superceded, but I am happy to accept that that is life. I was lucky to have the honour of being the first to resurrect this record and thanks for that must go to Peter Keen, my former coach, and Roger Legeay, my former team manager, who came up with concept that the UCI then adopted.”

In line with the requirements of an athlete’s hour record, Boardman’s 2000 record was set on a bike similar to that used by the Belgian Eddy Merckx when he set his 49.431 standard in Mexico, 1972. The Briton’s farewell ride as a professional saw him add ten metres to this mark, the new record standing for almost five years.

“I have not yet seen any images of Sosenka’s attempt but providing he broke it in the same spirit in which it was conceived - in other words, a round tubed bike with no aero advantages and full doping control procedures, then I offer him my warmest congratulations,” he says.

“The mark was always going to be beatable; hard but beatable, so I can’t say as it came as much as a shock. That said, I am somewhat surprised from the quarter from which this came. Despite being 29 years old, perhaps this achievement means we will now see Sosenka step up another level in the world of cycling.”

Cyclingnews asked Boardman about his requests earlier this year for the UCI to take and store blood and urine samples for future testing. At the time he said that this would ensure a level playing field for all record attempts, as well as helping Tour de France champion Lance Armstrong - who was then considering a record attempt - to convince his doubters that he was clean.

He still feels this would be a good idea. “I am certainly not insinuating anything regarding Sosenka’s efforts, a person whom I know nothing about, when I say it would be great for the record itself if the UCI could take steps to take and store samples for future retrospective testing,” he said. “That was something I asked for before my attempt, but it was sadly never put in place. This would allow the public to have complete faith in this blue ribbon record and remove any possible speculation.”

Just as Graeme Obree’s improvement of Francisco Moser’s hour record (now called the absolute hour record due to the technological advancements employed) did twelve years ago, Sosenka’s breaking of the mark will presumably lead to a burst of new attempts on the standard. However, the list of potential riders for such a bid is extremely unlikely to include Armstrong, who will retire from cycling after this year’s Tour ends on Sunday.

“I was a little sad to hear Lance was no longer going to attack the record. That could only be good for its ultimate long-term status,” says Boardman. “But I can’t say that I blame him, as what else has he got to prove?”

…This is the reason you can not simply compare the weights of two wheels to detemine which will spin longer. If you took a 20 lb wheel that was not uniform, rather it just had super heavy gold rims, then it would probably not spin nearly as long as a disc of uniform thickness that was half or its weight. The smaller the moment of inertia, the longer it will spin. This is the same reason why the extra 400-500 grams of a powertap are completely irrelavant. Those extra grams are at the center of the wheel and therefore essentially irrelevant, especially on a flatish course.

Er…I know what you were trying to say but you contradicted yourself a few times. An extremely heavy rim will spin LONGER given a constant starting angular velocity than one with the weight spread over a disk. This is why disc wheels can accelerate pretty fast, despite the additional mass (30% more than a typical wheel). A HIGHER angular moment of inertia implies either larger mass at a given CG radial distance or having the CG radial distance further from the center of rotation. As you said correctly, the extra 500g Powertap is basically irrelevant as they are at the center of the wheel. The disk isn’t such a huge acceleration penalty because the CG of mass isn’t as far from the center of the wheel even though the total mass is higher. A good example is the 650 trispoke vs 700 trispoke (see analyticcycling.com)…

650: 1207g, Ic 0.0683
700: 1346g, Ic 0.0904

Weight increases by 11%, moment of inertia increases by 32% by moving the mass outwards by about 8%. The 650 will accelerate faster given the same force, but given constant drag forces (bearing and aero, etc) it will also slow down faster than the 700.