CycleOps Cervo 2.4 Pro Computer
While we look at the CycleOps Cervo (pronounced "serv-Oh") 2.4 Pro computer as a gateway drug to riding with power, that's not really a fair assessment. The unit is a great stand-alone computer, even though Saris sells it as an intermediate step on your way to power.
Yes, most people are probably going to buy it with the idea that it's a souped-up bike computer that can receive signals from a wireless PowerTap 2.4 hub. Buy the computer new and get the wheel used on eBay or off a clubmate or wait a year and get a new wheel then. Good plans all.
Still, it deserves consideration as a bike computer. The Cervo, an Americanization of the French word for "brain," comes packaged in a nice zippered box. Inside is the Cervo computer head, a speed sensor, cadence sensor, heart rate monitor strap, 12 zip ties, a CD and a DVD. The DVD is Allen Lim giving power advice. As we wrote above, CycleOps sees this as a step toward power. In terms of compatibility, the sensors will work with any magnet, and the heart rate monitor will work with any ANT+ compatible strap. The cadence sensor can be converted to a speed sensor in a pinch by taking out the battery and moving the blue-colored switch inside the unit (and the reverse for the speed sensor). Rare earth magnets can be used in place of the cadence magnet, but too strong a magnet will double the cadence value. .
Think bike computer! It's wireless. If you've ever wired two sensors to your bike, you know this is a slow task and that it rarely looks good and leaves you concerned that something somewhere somehow will cut one of the wires. A typical fear is that over-zealous pulling on a zip tie is enough to sever.
Second, it has three lines of data, two big, one small. For people used to no data, three lines seems like waaaaaay toooo much. Initially, it is. In the "Precautions: Important" section of the manual, the second thing they recommend is "Keep your eyes on the road. Do not become overly engaged with the Cervo 2.4 display." The emphasis is theirs. Point one is to consult a physician. Wisely, point three is "We recommend familiarizing yourself with computer functions while stationary." A great idea.
While you can use the included PowerAgent program to modify the settings on the Cervo computer head, taking the time to set them directly on it is well worth the time investment. The process can be maddening as you try to remember which buttons do what, but ultimately the effort will speed up your familiarization with using the Cervo.
Read the owner's manual with the computer head in hand. While following the Cervo's instructions in a linear fashion would have you set up the sensors and stem bracket first, we found that another way would be better. Begin with making sure the Cervo has the latest firmware. Ours came with 5.33. 5.67 is the version that was current when we started testing the unit. The computer head reveals the version of firmware your computer head has each time you turn on the unit, which can be done by pressing either button. You get the firmware update off the CycleOps website. You download it into the Cervo via the included USB cable. The computer head has to be on and the unit has to have "host" on the screen.
While you're on the CycleOps website, make sure you have the latest version of their PowerAgent software. Our Cervo came with PowerAgent 7.1 on CD. 7.2 is current as of this writing. Don't bother installing an older version of the software; go straight to the latest. The software works with Linux, Mac, and Windows.
Once the firmware and software are upgraded and installed, we found setting up the Cervo before installing the on-bike hardware to be wiser, if for no other reason than you'll need to set it up before the sensors will register what you want in the places you want it. We set ours up with the heart rate (current and average) at the top, speed (current, average, and max) in the middle, and then with the option to scroll through cadence, average cadence, distance (trip and total), and time (trip, time of day) at the bottom.
Now that the Cervo is set up, run through the functions with the unit in your hands. Get a feel for how long it takes to get to the "int" "find," "clr" and "set" features. There are only two buttons on the computer head and they're asked to do many different things. Know what they do and in what order before heading out on the road. This might seem unnecessary, but we know several people who lost ride data because they cleared the data instead of setting an interval marker. Finally, make sure you're comfortable switching between interval mode and current.
Once you're comfortable with the navigation and data of the Cervo, set up the hardware on your bike. The speed sensor can be mounted next to the rear wheel or front, and we found we didn't need to be terribly precise with how close we got the sensor to the magnet. We also found that for the sake of magnet stability that mounting the cadence magnet just inside of the pedal spindle was a good placeholder and sufficiently out of the way that our foot or ankle wouldn't hit it during the pedal stroke. We were surprised that we never got the "transmission" icon in the upper-left of the display, which is supposed to tell you when the Cervo can read the sensor signals, but since we saw speed, cadence, and heart rate, it doesn't seem to matter.
We mounted the Cervo on our stem. Many consider this a "cleaner" look than on the handlebars. Since we're used to reading our data in front of our handlebars, it did take some time getting used to rolling our eyes down and reading data off the stem.
We did a ride where our cadence didn't turn on. And then our speed disappeared after heeding the call of nature. After we went home and scrutinized the manual, we realized that the computer head needs to find the signals from the heart rate monitor, speed sensor and cadence sensor before it can measure them. This occurs in the first few moments after turning on the computer head, though they can be re-found by holding down the two buttons until "find" appears on the screen (holding for too long will clear all data). For simplicity's sake, we recommend starting out on your ride with the unit off and starting it a few seconds in. However, some racers might find it better to program in the identification number of each sensor into the computer head from the computer before a race (this is detailed in the owner's manual under "Computer Setup 5"). This is because the Cervo might find the signals of the riders next to you in a crowded race field. The Garmin-Chipotle team mechanics give their riders a fresh computer head by dropping it in their pocket when the riders flat a rear wheel in races, so pre-programming might be a good idea if you can do it.
We recommend saving the first rides of any new gear for an easy day, preferably at the start of an easy week. The same goes for the Cervo. Even with familiarizing ourselves with the unit pre-riding, it took a few rides to get comfortable moving through all the data screens.
Since this is a downloadable unit, a portion of the ride experience is downloading and reviewing your ride data. While using the PowerAgent program isn't essential, and Peaksware and other interpretative programs can read Power Tap, using it could help your riding. Arguably including the software with the unit drops the price as it gives you a ride diary along with the computer head.
It is certainly cheaper to use than buying Peaksware, and the software is fairly easy to understand and use, though here, too, the program is really designed for power data. You start by creating a file for yourself.You'll need to know your heart rate zones to generate values for different zones. We tried their auto-generate feature, which is based on your lactate threshold heart rate; the results seemed much higher than we'd use, so we manually entered in the values. While the summary page is somewhat useful, it is distracting that half of the screen is used for power data, which you don't have and it creates charts you can't use or erase. We preferred to look at the "details" chart. Here, you see a graphic representation of your ride, and you both see intervals and can create intervals within the file. You can also compare rides to each other.
Aside from the hard sell on power from Saris, the Cervo is a pretty good downloadable wireless computer. You get lots of choices on data to see and analyze. While learning the navigation takes a while, it becomes intuitive once an understanding is developed. For those who are looking for an intermediate step towards power, it's a great step in that direction.