V. Review of Models Tested

1. Sigma Sport BC 600

        After exhaustive testing, I find this model an excellent choice as a revolution counter. Although  discontinued, I notice that as of May 2004 the BC 600 is for sale by Nashbar for $12.95. Sigma Sport say that it will be available by special order long after it disappears from stores.

    The mount is very rugged with no small pieces of plastic to easily break off and destroy it as I have found with some other brands. Contacts are very positive and should not break down. Like all Sigma models it is easily attached within a few seconds to the handlebar with an O-ring. A stem mount is available that is used with the Targa and other older models.

    The sensor also attaches quickly with an O-ring and or electrical tape to the top and inside of the fork. I usually discard the foam on the back of the sensor. Alignment with the wheel magnets is easily checked, because if this is correct, the broken circle in the upper right-hand side of the meter display rotates every time a magnet passes the sensor. Most models do not have any similar indicator.

    When the wheel is rotating very fast, the meter tends to skip the display of one or two digits. However, this is of no consequence, because the correct number of revolutions is shown when the wheel stops.

    The only disadvantage for general bicycling is that this meter does not display average speed.

                                                                                                                                                                                                                                                                                                                                                    BC 600 showing mount and sensor

2. Bike Planet Protégé 5.0, 8.0, & 9.0

    The Protégé 8 was one of the first models that I exhaustively tested against the Jones and I find the Protégés excellent models both for use as  revolution counters and for other bicycling uses. Recently, I have discovered that these models are unique in that they allow a circumference setting of 9.999 meters and thus operation with a single magnet to record individual revolutions.

    The 9.0 shown on the right has nine functions displayed on four lines. The first three lines display speed, ride time, and trip distance. For the fourth line there is choice between displaying odometer for all wheels used, odometer for one of two wheel sizes, average with maximum speed, and temperature with clock . Choice is made by simply pushing the computer forward and then releasing it. Holding the computer forward  for three seconds resets the display. Fahrenheit temperature is shown in mph mode and centigrade temperature is shown in kph mode. Accuracy seems quite good except in in bright sunlight when centigrade temperature can be as much as ten degrees high. The photograph shows a revolution count of 2571, a temperature of 30 centigrade, and a time of 1:49. Since this data is pertinent to course measurement, the 9.0 is the best model to purchase (recent sale price is $22).

    The 8.0 is similar to the 9.0 except it lacks temperature read-out. The 5.0 has only five functions.

    The 8.0 and the 9.0 hold two wheel circumferences in memory and the one selected is indicated by a 1 or 2 in the upper left-hand corner. (In switching the computer from use as a revolution counter to that for regular bicycling it is very convenient to switch between circumferences in memory by simply pressing a button on the back of the computer.) There is also a speed comparator triangle in the same corner when the wheel is moving.

     Note that I have not normally used the magnets supplied with the computers or installed the sensors on the lower part of the forks as recommended by the manufacturer. Instead I have used Sigma Sport magnets and mounted the sensors on the upper inside of the forks. The Protégé magnet is very heavy but can be used with the sensor on the upper inside of the forks. Necessary alignment is shown in the photograph and in the geometry of my forks clearance is 2 mm without any modification.

    A nice check feature is that every time a properly aligned magnet passes the sensor, speed, ride time, and speed comparator displays all change.

    When using these computers as a revolution counters, change of the display is particularly smooth no matter how fast the bicycle is ridden.

    After five minutes of inactivity the display goes blank except for the clock. This should not normally  happen in course measurement, but if it does, it is important to note my following discovery. On resuming the ride the screen will be reactivated as the next impulse is received, but unfortunately this impulse will not be recorded. This problem is avoided if the display is reactivated by pushing the computer forward on its mount before resuming the ride.

3. Sigma Sport BC 800 (2002) and Tara

    These two computers are essentially the same because the Tara is just a more rugged version of the BC 800. Also, the Tara mount is designed for stem rather than bar mounting.

    These computers are excellent choices for both use as revolution counters and other bicycling. Although supposedly discontinued, I notice that as of May 2004 the BC 800 is for sale by Nash bar for $17.99. The model with SK chip has also been on sale recently for $10 and this comes with a bicycle harness.

    Notable features are average speed and a memory that holds two circumference values. One of the latter can be the 2500 required for use as a revolution counter and the other can be that used in normal bicycling. Switching between the two is simply a matter of pressing a button on the back.

    Note though that I have discovered a peculiar quirk in that after zeroing the display, the first impulse is not registered. Correct for this as follows. At the start of course measurement, aligned the zero spoke with the starting point and then turn the wheel backwards rather than forwards about 0.1 rev before zeroing the computer.

4. Sigma Sport BC 500

    This is the cheapest model in Sigma Sport's latest line and is a good choice as a revolution counter.

    The mount is a very rugged twist lock design. (Not that there was much wrong with the old design!) It allows a choice between mounting on the bar or on the stem.

    Battery is a lithium type that increases operating life to three years from only two in older models.

    A novel mode is that in which all functions are continuously scanned.

    The one annoying feature is that after zeroing trip distance used to display revolutions during course measurement, the display returns to trip time. Four more clicks are necessary to return to trip distance.

   

                                                                                                                                                                       

5. Sigma Sport's latest models except the BC 500

    Sigma Sport's latest models have an option of selecting display in one of three languages. There seems no point to this option, but unfortunately it is associated with such a degradation in performance that none of these models are suitable for course measurement with four magnets. Performance is sluggish such that it takes about three seconds after a stop before the last increment comes up. Also, very occasionally an impulse is missed. Some of these models may work in the single-magnet mode, but in general they should be avoided.

 

6. Cat Eye OS1.1

  

        The OS has a powerful computer so that operation is exceptionally smooth and reliable. Also exceptional is the huge display as can be seen from a comparison with that of the Jones in  the photograph on the right. The display of 1211 rev is uncluttered by other parameters. Like other Cat Eyes it is exceptional in having a manual mode in which operation can be switched off temporarily. This is a very useful asset during course measurement.

    The sensor is not the usual Cat Eye design as can be seen from the photograph on the left, which shows the OS sensor on the left of the fork and the usual design on the right. Correct alignment with a Sigma Sport magnet is shown in this  design of mine for sensor mountings.

    Like the Protégés the OS goes to sleep after three minutes of inactivity, and to avoid missing an impulse must be awakened by pressing the start button before resuming measurement.

    At a low of $60 on-line the OS is a little expensive, but for the bicycle enthusiast the expense will be offset by the fact that workouts are stored automatically for up to six years.

 

7. Cat Eyes other than the OS1.1

    The Mitty 8, the Astral 8, and the Enduro 8 (on the right) appear to be very similar models except that the Astral has cadence capability and the Enduro has heavy duty wiring. All have the useful capability of switching off operation temporarily. Sigma Sport magnet alignment with the sensor is shown above on the left. None of these models performed satisfactorily in four-magnet operation, but did so in two-magnet operation except for a rare missed impulse by the Mitty. All probably work satisfactorily in single-magnet operation.

    The Velo 5 recorded impulses accurately in two-magnet operation at normal bicycling speeds, but failed to record any when the wheel was rotated slowly.

    Indications are that the Cordless 7 might just work in single-magnet operation but operation would probably be unreliable. In any case the model has nothing to recommend it and many disadvantages such as a bulky sensor that cannot be mounted inside the forks, tricky alignment, and an extra battery to maintain.