When it was introduced in the early 90's, the Avocet 50 was a breakthrough in cyclocomputers. For the first time, an accurate means of measuring altitude was available to the cyclist. Unfortunately, the unit had several major drawbacks. First, it was about as waterproof as toilet paper. Second, it had a 30-foot climb threshold meaning that any climb under 30 feet in height went unrecorded. The designers put the 30 foot threshold in because in their words, "we didn't want anybody riding from Palo Alto to Gilroy and accumulating 2000 feet of altitude gain by riding over freeway overpasses and believing they could climb."

Technology and attitudes have improved over time and two new cyclocomputers, the Specialized Speedzone Pro (renamed Speedzone Classic for 2002) and the CicloSport Ciclomaster 414 Alti, offer accuracy and features far superior to the old AV50. Both computers display current air temperature and give the % grade of your current position (up, down or flat). For those who enjoy climbing, the inclinometer feature is a real plus. Also, the current speed function displays in tenths of miles/kilometers which is a major improvement over the five tenths increments used on the AV50. The Speedzone and Ciclomaster use the same computer chipset. The differences are in the packaging and the sampling of the available data. And there are important differences.

Both computers use wireless technology to send the signals from the sensor to the computer. With the Speedzone, the receiver and computer are built into one unit, requiring a single battery for operation. CicloSport, on the other hand, built the receiver into the handlebar mount so you require separate batteries for the mount and for the computer. This may or may not be a big deal, but unnecessary complexity should be avoided. One advantage of the Ciclomaster mounting system is that you can replace the wireless sensor with the wired sensor of the lower priced units, further reducing the complexity and bulk.

The push buttons on the two units behave differently. There isn't enough space in this review to get into the details, but I found the design philosophy behind the buttons on the Speedzone to be more intuitive and easy to use.

As far as the layout of the display, there is no real difference. The Speedzone display is a bit brighter which is nice when trying to read it while standing up. Both models display current speed all the time, with all other functions being displayed below the speed and toggled through using the push buttons.

With respect to what is displayed, it appears that neither manufacturer did extensive usability studies. On the Speedzone you must toggle through 11 different functions which is extremely cumbersome and time consuming. The designers should have taken a page from the AV50 and grouped some features together such as average speed and maximum speed, toggling between the two with a special button sequence. The Ciclomaster is a bit better in this regard; the two buttons on the case allow you to toggle the data in opposite directions. However, such data as rate of climb seem to me to be not all that important and should have been grouped with another piece of data.

A major drawback for ultra riders is that the Speedzone automatically resets itself after 10 hours, and you lose all record of your distance, average speed, and accumulated altitude up to that point!

The CicloMaster stops recording automatically after 24 hours. If you want to continue recording you must start this mode again which sets everything in the display to zero (daily distance and so on). But the computer makes a beep when it stops recording, so you get reminded to restart it. The old data is not lost. The computer stores data for 64 hours in a ring memory. When you download the data to the computer it is possible to fit data sets together.

Also, the Ciclomaster has a power function which attempts to use the combined weight of rider and bike to make a calculation of current power output. The designers got it all wrong and until they can fix it, it should be left out of the computer all together.

I field-tested the two computers side by side and with an AV50. Both machines were dead nuts with respect to ground speed and current altitude. The major differences centered around how the two units measured altitude gain/loss. The Ciclomaster has a threshold of five meters (16.5 feet) for reporting any climb meaning that any climb under that height will go unreported. The Speedzone appears to do no filtering, I have seen climbs as small as seven feet reported. This may indicate a climb threshold of 2 meters (6 feet) but there is no documentation of a climb threshold for the Speedzone.

Because it appears that the Speedzone reports any climb, regardless of height, I was concerned that even small changes in air pressure might be recorded as a gain in altitude. To verify the accuracy of the Speedzone, I did the same 115-mile ride on three separate days and in differing weather conditions. The three rides reported values of 7090, 7080 and 7100 feet of climbing. That's pretty good. Because of the threshold on the Ciclomaster, it has the potential to accumulate less altitude gain than the Speedzone. Depending on the terrain, this difference will vary. For my rides in the Santa Cruz Mountains of northern California, the difference was in the range of 5-6%. As a comparison, the AV50, with its climb threshold of 30 feet, shows a 9% lower altitude accumulation than the Speedzone.

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The computers also show significant differences when displaying percent gradient. One of the major drawbacks of the Speedzone is that it uses the altitude data collected for the past 20 seconds for calculating gradient. This leads to a lag in reporting the data which is most notable on short climbs. The Ciclomaster appears to do a much shorter sampling rate, but I still found some of the values displayed to be a bit suspect. On long climbs with a constant gradient, this feature was accurate and useful. More work needs to be done by both manufacturers to make this feature useful on short climbs.

Each computer has its share of other annoyances. The Speedzone needs input from the cyclist to turn the computer on when it is in "sleep" mode. Otherwise, even when the bike is moving, no data will be accumulated. The computer should be able to turn itself on automatically when it detects wheel speed. Also, when you want to reset the current altitude, the unit goes back to a preset value rather than allowing you to start from the value currently being displayed.

The push buttons on the Ciclomaster are very difficult to use on the unit I tested. Sometimes they do nothing, sometimes they exhibit "bounce" and other times, they actually work. This is very annoying and, for me, is a major negative of the Ciclomaster. Also, I would delete the power and rate of climb features, they just don't work correctly or give useful information.

Overall both computers are a step up from the AV50. The cases are much smaller. They provide all the features of the AV50 at least on par or better than the AV50 and they include several other new features, most notably temperature, gradient and displaying speed in tenths of a mile/kilometer. Personally, my choice would be the Speedzone. However, with a bit of re-tooling, the Ciclomaster could be a good choice as well.