Monday, February 23, 2015

Tour magazine light bike test March 2015

Upon returning from a trip from KAUST in Saudi Arabia last week I connected through Frankfurt Airport. I was a bit grumpy because security had just confiscated my package of delicious Jeddah figs claiming they were a liquid hazard. It wasn't just that I was to be denied of the chance to share what I'd been finding so delicious during my 6 days at KAUST, but just as equally it seemed wrong for such fantastic fruit to go to waste, all over a ridiculous policy bourne of international paranoia. But my mood was slightly lifted when I spotted in a newsstand across from my gate the golden apple of German journalism: Tour Magazine. Depite a painfully long and even more painfully slow line at the stand, I risked being late to my boarding to buy it.

And I wasn't disappointed. Edition 2015.03 of Tour had a quantitative review of 3 of the lightest frames you can buy:

  1. Trek Emonda: The Trek Emonda line is actually relatively heavy. Only the top-of-the-line SLX with the pricey vapor coat option is particularly light, and it's spectacularly so. It was the lightest frame in the Tour test, an impressive result given the competition. They tested it with the full-bore weight-weenie version, which breaks the 5 kg barrier w/o pedals.
  2. AX Lightness Vial Evo: The Vial Evo is a stock design from AX Lightness, known for its super-expensive super-light marginally functional components. But when you want the lightest possible bike, you can't let money or functionality get in the way. The Vial Evo actually isn't particularly expensive in comparison to the competition here. It tied for second place on frame mass with the Cervelo RCA.
  3. Cervelo RCA: with the exception of its relatively short reach geometry, the Cervelo RCA may be the epitomy of frame design. In addition to being spectacularly light, it's also fairly aerodynamic, and continues the Cervelo tradition of pencil-thin seat stays for vertical compliance to yield a smooth ride.
  4. Rose X-Lite: This frame was substantially heavier than the other three, and I wasn't exactly sure why it was in this test. Perhaps it was for purpose of comparison.

In addition to these Über-bikes, they added 8 bikes "under 1500 Euros": bikes typically outfitted with Shimano 105 or even some Shimano Tiagra designed for more entry-level riders. It was an interesting comparison of what you get for the mega-bucks, for bikes costing at least 8 times as much.

The interesting thing about Tour is they tend to use a static point scale. So if they're testing super-light bikes designed clearly for people who put a very high priority on mass, they still use a point scale on which only a minority of the points come from mass. This is arguably okay, but what ended up happening is Tour discounted mass completely.

This happened because Tour uses a "school grade" system for rating components of a bike's merit. So instead of using mass in some unit, such as grams, they assign it a number from 1 to 4, comparable to grades in a German school. And like the German school grades, grades don't come in any arbitrary value, but rather a relatively small number of discrete values.

Here's the mass ratings for the frames plotted versus the total frame mass:

The 4 super-frames are the three symbols each rated 1. This goes from the Emonda, the lightest, to the RCA and the Vial Evo, which are tied, then to the Rose X-Lite. Ignoring these 4 points, I fitted a straight line through the points representing the cheaper bikes. The coefficients for this fit are shown. The X-Lite falls under the trend line, indicating its 1.0 rating on mass is somewhat favorable. On the other hand the Emonda sits above the trend line. It's getting relatively cheated by that same rating.


Not surprisingly, the X-Lite won the rating contest. If you put more carbon on your frame you can make it stiffer, and Tour magazine loves stiffness. Additionally added carbon allows programming in compliance while maintaining strength. But it's clear that the rating system is artificially compressing the weights of these these four frames into a ssingle value. It's silly, really.

Wednesday, February 11, 2015

petition to ban smoking from San Francisco sidewalks

I've been super-busy with a new research position at the University of California at Berkeley. This has been fun, but leaves little time for blogging. But I made time to do my first-ever petition, for the Board of Supervisors ban smoking on San Francisco sidewalks.

I've written about this before when I was exposed to smoke while waiting in line at the Bicycle Film Festival. Well, it turns out smoking is already banned for waiting in lines on sidewalks, so I was already justified there in asking the smoker to take it elsewhere had I chosen that approach. But in many cases exposure to smoke on sidewalks is just as unavoidable, in particular for small children who aren't free to go where they want. In some cases the child is even in a stroller being pushed by a smoking parent.

This has become a bigger issue with me since I started running more. When running on a sidewalk, running the gauntlet past a group of sidewalk smokers is unpleasant in addition to profoundly unhealthy. There's one particular section, on Stanyon near Haight, where the smoke is particularly bad, and this has nothing to do with Big Tobacco, or any tobacco, for that matter... but it's generally a problem.

It's really time for acceptance of exposing other people to toxic gases to stop. This petition is my little attempt to do something about it. Maybe it will help, maybe not.