Lennard Zinn

VeloNews technical writer Lennard Zinn is a frame builder, a formerU.S. national team rider and author of several books on bikes and bikemantenance. This marks the beginning of Zinn's weekly VeloNews.com columndevoted to addressing readers' technical questions about bikes, their careand feeding and how we as riders can use them as comfortably and efficientlyas possible. Readers can send brief technical questions directlyto Zinn. We'll try to print a representative sample of questions eachThursday.Question: Do you have any advice for correcting leg lengthdiscrepancies?  I have undergone an

There are four different colors of Treks you will see U.S. Postal racing on in the Tour. These are two different road bikes and two different time trial bikes. The two road frames you can buy, and there is no difference between them and models sold in bike shops. The two time trial frames are strictly team issue. This use of stock frames is unique at that level of racing. Almost all top riders have frames custom built especially for them, often by a manufacturer other than the one whose name is on the frame. In fact, Trek claims that Lance Armstrong's two Tour victories were the only ones

In addition to the teams mentioned yesterday, Kelme is also using wheels with carbon braking surfaces – namely Shimanos with carbon rims. Like Shimano’s aluminum wheels, they have paired spokes with their heads in the side of the rim and nipples at the star-shaped hub. Kelme uses Shimano’s red cork brake pads with them. ADA also makes a rubberized cork pad for carbon rims that are claimed to provide consistent braking on carbon rims, even when wet. Its pad fits in both Shimano and Campagnolo brake-pad holders, but not in Corima pad holders. Telekom has been using ADA pads in the past but

The wheels are arguably the most important part on a bicycle and are thus the source of constant efforts for improvement, and, for a team, to find an edge over, or at least parity with, the other teams. There are a number of physical properties of a wheel that teams have to consider. A gram of rotating weight out at the rim is worth about two grams on the frame, so weight reduction is obviously critical. Wheels are big egg beaters of the air, and any reduction in their aerodynamic friction can pay off, especially when the rider is not sheltered in the peloton. In order that the rider can

Look time trial bikes, which took a black eye a few years ago with some weak forks, pulled off the ultimate Tour victory – an entire team winning a stage on them. This, the day after Laurent Jalabert notched a win with a Look road bike, and two days after Stuart O’Grady took over the yellow jersey riding yet another. There are more Look bikes in this Tour than any other make, as four teams (Credit Agricole, Kelme, Big MAT and CSC) are riding them. That puts Look ahead of Pinarello, which has three teams (Telekom, iBanesto and Fassa Bortolo), and Colnago, which has two (Rabobank and Mapei).