Monday, January 22, 2007

Some more about wheels... and airflow

My friend, he with the Six13 and Lapierre, went on to say, "Yeah, but the more I thought about the test (see my previous post) the more I question the relevance. Most of the top tyres and almost all of the aero tyres were tubulars. How would the stiffness compare on the equivalent clincher? You can get clincher Ritchey WCS carbons for instance. They didn't use that many top end clinchers in the end, I would've liked to have seen Easton's top clincher in there."

To which I would say that clinchers are by design not as stiff, certainly laterally but in every way, as a tubular (ie glue on) rim, whether made of carbon or not. It's stiff by design, being a closed loop, whereas a U-shaped rim can bend more easily.

Undaunted, he went on: "What has me thinking is the front to rear stiffness difference in the Campy Eurus. I do talk about the freaky handling of the Lap, but maybe it was the wheels?"

Which had me thinking about my old Campag 24 spokers. Light, great for climbing, but hopeless in corners. Just too soft laterally (it felt it was laced with spaghetti spokes, cooked ones). Sometimes a bit more weight (as in more spokes) is worth it - again it's horses for courses.

My friend also commented that "the R560 Shimano does pretty well, considering it's their 105 spec wheel. Just shows how far Shimano have come with their wheels and they definately are the best value wheel on the market at the moment."

Probably a good call. I still like Mavics. Those sealed bearings last a long time (mine have lasted 16 years without a failure, and with minimal maintenance).

He also "thought the 50kph (test) was a bit extreme, but I did like that they tested a variety of angles, something that you question when you see the Cervelo Soloist design... surely it can't be that good at anything except straight on (ish)?" Of course on a bike you tend to go forward (hopefully!) so you are always penetrating the air straight on, so the Soloist does make sense. It also has a greater side profile surface area so maybe it is susceptible to crosswinds, but I have trouble in 40-60knot crosswinds on my regular bikes, so maybe it's just a matter of degree?

No comments: