Looking for a new wheelset for the 2008 season? Here are some wheelsets that won’t dissappoint you:

Zipp 202 (Tubular)

Zipp 303 (Tubular)

Zipp 404 (Tubular)

Shimano 2008 Dura Ace Carbon WH 7850 (Tubular)

Mavic 2008 R-Sys Road Wheelset (Clincher/Tubular)

Mavic 2008 Ksyrium SL Road (Clincher/Tubular)

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Kraig Willett has made a comprehensive review of the three most used power meters: SRM, Power Tap and Polar. He explains in details how these power meters measure power output and presents results from his tests. He gives us a very detailed review of how SRM, Power Tap and Polar perform in price, performance, and durability. The review might be a bit difficult to understand for beginners, but it is really worth reading.

Here are some of the points from Kraig Willett:

On how the SRM crank system measures power output
“Instrumenting a mechanical structure allows one to convert the phenomenon of interest into an electrical signal that can be subsequently analyzed, mathematically manipulated, and then displayed to the user. Strain gages do just that in the SRM power measuring device.

The strain gages that SRM uses are nothing more than a piece of foil embedded in a plastic carrier. The resistance of the foil element changes depending on how much it is stretched/strained. The strain gages unique characteristic of changing resistance under strain is what allows the mechanical deflections that naturally occur in the structure to be converted into an electrical voltage signal.”

On accuracy of power meters
“Additionally, it can even be argued that absolute accuracy is not an issue, but rather, consistency over time or measurement repeatability is most important.”

On installing a Power Tab hub
“The Power Tap system is just about as close to ‘Plug and Play’ as one can get. The straightforward steps of installing a cassette and a tire on the wheel built with the Power Tap hub are nothing too difficult for your average bike racer. Once these steps are accomplished, one must simply drop the wheel in the dropouts and install the receiver and CPU mount with the supplied zip ties. The whole process should take 30 minutes at most.”

Read the full review of SRM, Power Tap and Polar

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Looking for the perfect Christmas gift for a cycling enthusiast? Here is a list with popular products that most cyclists will love:

Power Meters

Cycleops PowerTap SL

Ergomo Pro training system 2006

Polar S625x Heart Rate Monitor with Power Kit

Home Trainers

CycleOps Fluid 2 Indoor Bicycle Trainer

CycleOps Magneto Indoor Bicycle Trainer

CycleOps Mag Indoor Bicycle Trainer

CycleOps Tempo Fluid Trainer

Heart Rate Monitors

Polar S725x Heart Rate Monitor

Polar S625x Heart Rate Monitor

Polar S625x Heart Rate Monitor with Power Kit

Garmin 305 Edge w/ Heart Rate Monitor & Speed/Cadence

Wheelsets

Zipp 808 Deep-V Road Tubular Wheelset

Zipp 404 Deep-V Road Tubular Wheelset

Zipp 303 Mid-V Road Tubular Wheelset

Zipp 202 Quick-V Road Tubular Wheelset

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Joe Friel has an interesting article about optimization of aerodynamics for time trialists. He has been doing some testing with differents setups of head position (aero helmet, head position etc.) and saved 77seconds. I can strongly recommend time trialists to have a closer look at that article and notice Joe Friel’s final comments: “I’m afraid many helmets on the market that are marketed as “aerodynamic” are actually less aerodynamic than a standard road helmet. And even wearing a decent helmet with the front down close to the eyebrows, while it may look good, is actually slower than with the helmet’s leading edge worn closer to the hairline in front.”

I found this link via PowerTap Geek that publishes a lot of interesting articles for PowerTap freaks.

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Many heart rate monitors and bike computers has a feature to measure the energy cost of the exercise. But can we believe these numbers? I have always been sceptical to these calculations since they are based on very few variables (percentage of maximum heart rate and total time). I have always said to my riders that they can use these numbers for fun, but don’t count on them when they cook dinner. There is probably huge variability in the quality of calorie metres, some gives a rough estimate and some doesn’t.

Can heart rate monitors be used to calculate energy expenditure?

Yesterday I found a study published in Medical Science of Sports and Exercise that tried to figure out how accurate the energy expenditure calculator of the Polar s-410 heart rate monitor was. They used three different calculations of the energy expenditure: 1) Polar s-410 using predicted values of VO2 max and maximum heart rate. 2) Polar s-410 using actual values of VO2 max and maximum heart rate. 3) Indirect calorimetry (You might have heard about this one in school…)

The results showed that the Polar s-410 did a quite good job for the men with no significant differences between the three calculation methods. The women’s numbers were overestimated when using predicted values of VO2 max and maximum heart rate. The estimation was better when they used the actual values but still overestimated with 12%.

Read the full article about Polar S-410

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Buying a heart rate monitor doesn’t have to be expensive. In fact a cheap heart rate monitor might very likely be one of your best investments in your cycling career. If there was a performance-improving per money index, I guess a heart rate monitor would rank in the top. It is possible to buy quality heart rate monitors like the ones from Polar or Cardiosport for reasonable prices. There are also several copy products, which also have a high performance and might save you a few bucks.

Basic heart rate monitors

All companies producing heart rate monitors have some basic models made for beginners. These watches have a very limited amount of details, but are delivered at a very fair price. Measuring of heart rate is very accurate at basic heart rate monitors because they use the same techniques for measuring as more expensive models do. Basically these watches measure the current heart rate and that is it. If all you want to know is the current amount of beats, a Polar Basic heart rate monitor could be a good choice for you. There are also some other basic models which offer a few options like target zones or average heart rate. Especially the avg. heart rate can be useful, exciting and motivating to use during training. I think that these options are an absolute minimum for a serious cyclist.

Advanced heart rate monitors

If you want to get more details and options about how your heart performs during the training session, you will have to invest in an advanced heart rate monitor. Here you will get more details about your performance and the monitor will store more data for you. E.g. how much time you have spent above you target zones. Some of the monitors in this category can be connected to a computer so you can make graphs of your training sessions. This can be very enjoyable for some people and very useful for others. The amount of data stored on these monitors is often limited, especially when you compare with how much data you can store on an iPod or MP3 player. For some reasons heart rate monitors have not taken part in this development. In many ways heart rate monitors are old fashioned, probably because of very few competing manufacturers. For many years Polar was the only reliable heart rate monitor on the market. Nowadays the competition is intensified, which makes the heart rate monitors both better and cheaper.

Professional heart rate monitors

If you have a scientific approach to your cycling or just want to get all details registered, you have to buy one of the professional heart rate monitors. These watches store huge amounts of data. Actually they can store every single beat from your heart. This makes it possible for you or your coach to make some very comprehensive analysis of your training on your personal computer. To get the full value out of a professional heart rate monitor like Polar s810, you need to have some interest in exercise physiology.

This article is Part Two of the Heart Rate Monitor Guide.

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