19 of 19 people found the following review helpful

Major Disappointment: Suffers from Electrical Interference, October 16, 2004

The RT 88 was a severe disappointment; I returned it one day after its purchase. The main draw in acquiring this unit was its cordless operation, which obviates a wire going from the head unit to the wheel sensor. The absence of a wire allows a cleaner look than corded models and reduces a chance of a snag, all for just a $10-$15 premium. Unfortunately, the rudimentary wireless connectivity is highly susceptible to interference other electronic and electrical devices.

Vetta (Acumen Inc.) acknowledges this interference is a known issue. Hence, I can’t recommend this cyclocomputer to anyone who might be near electrical devices (cell phones, CD players, utility transformers, power lines) while using the RT 88.

The first red flag appeared immediate after I programmed the final setting and switched to the main operational mode. The speed was fluctuating between 37 and 48 miles per hour. At first, I thought the device was simply malfunctioning. After some experimentation, I realized that it was sensitive to interference generated from my laptop anywhere within a three (3) foot radius (sans wireless connectivity enabled). While I don’t ride with a laptop, I do have a cell phone mounted on my handlebars. Call transmission makes the RT 88 go haywire, showing excessive speeds.

After several phone calls and emails to Vetta tech support, I was finally contacted by a Vetta staff member. The tech support person (marginally technical) acknowledged that interference is a known issue with the RT 88. Even CD players cause this problem, he said. Here in Manhattan, bicycle store employees suggested that underground electrical equipment also has the same effect. However, I never bothered to install the unit on my bike.

When I indicated to the Vetta representative that such interference problems never occurred with my [$300] Polar S710 (current successor is the S-725), his reply was “that it why it costs $300″. It dawned on me that Polar boasts their sensors are coded. Presumably this means that the heart sensor (and wheel sensor) was paired with the head unit. However, it isn’t clear what type of wireless connectivity is used.

Even though it is fairly obvious when the speed is erroneous, the erratic jumps cause a permanent problem by dramatically affecting the trip distance and odometer.

In summary, the RT 88 *may* work for your particular usage pattern. However, no one should have to be concerned about the accuracy of such an instrument.

]]> http://www.cyclecomputerreview.com/news/how-do-you-install-cycling-computer-so-it-tells-precise-data-on-speed-and-travel/comment-page-1/#comment-2139 Ben P Sat, 19 May 2012 02:45:31 +0000 http://www.cyclecomputerreview.com/news/how-do-you-install-cycling-computer-so-it-tells-precise-data-on-speed-and-travel/#comment-2139 The angular velocity of the wheel is the same at any point along its radius. Therefore, it doesn't matter where along the spoke you attach your magnet as far as accuracy goes. Pros install their magnets towards the tire only because it facilitates fast wheel changes during a race plus it makes for a neater install because you have to hide a shorter length of wire. Others like to install the magnet towards the middle because the weight of the magnet remains away from the periphery of the wheel, theoretically making for less rotational weight. I've tried both and I don't notice a difference. For accuracy, I measure the radius of the wheel/tire combo going from the hub to the edge of the tire. Wider tires usually also have larger circumferences. Read the manual and see how your measurement fits into the computer setup. The angular velocity of the wheel is the same at any point along its radius. Therefore, it doesn’t matter where along the spoke you attach your magnet as far as accuracy goes. Pros install their magnets towards the tire only because it facilitates fast wheel changes during a race plus it makes for a neater install because you have to hide a shorter length of wire. Others like to install the magnet towards the middle because the weight of the magnet remains away from the periphery of the wheel, theoretically making for less rotational weight. I’ve tried both and I don’t notice a difference.

For accuracy, I measure the radius of the wheel/tire combo going from the hub to the edge of the tire. Wider tires usually also have larger circumferences. Read the manual and see how your measurement fits into the computer setup.

]]> http://www.cyclecomputerreview.com/news/how-do-you-install-cycling-computer-so-it-tells-precise-data-on-speed-and-travel/comment-page-1/#comment-2138 bikernoj Sat, 19 May 2012 02:08:09 +0000 http://www.cyclecomputerreview.com/news/how-do-you-install-cycling-computer-so-it-tells-precise-data-on-speed-and-travel/#comment-2138 You have to use the manual, as each manufacturer has instructions specific to their product. Most cyclometers will have a place where you input the circumference of the wheel, though only some of them actually say so. You can input the standard values included in the manual if you like, but the best way to be as accurate as possible is to do a "rollout" measurement. Basically, make a mark on the ground next to your tire, roll the bike straight forward one revolution, and make another mark on the ground. Measure between them in either centimeters (3 digit) or millimeters (4 digit) and input that number into the computer. The placement of the magnet makes no difference, because the magnet only tells the computer that the wheel has traveled the distance of one revolution each time it goes by the sensor. Velocity = Distance x Time, so the computer calculates the distance you have traveled (the number you input) x the amount of time you ride to give you your speed. You have to use the manual, as each manufacturer has instructions specific to their product.

Most cyclometers will have a place where you input the circumference of the wheel, though only some of them actually say so. You can input the standard values included in the manual if you like, but the best way to be as accurate as possible is to do a “rollout” measurement.

Basically, make a mark on the ground next to your tire, roll the bike straight forward one revolution, and make another mark on the ground. Measure between them in either centimeters (3 digit) or millimeters (4 digit) and input that number into the computer.

The placement of the magnet makes no difference, because the magnet only tells the computer that the wheel has traveled the distance of one revolution each time it goes by the sensor. Velocity = Distance x Time, so the computer calculates the distance you have traveled (the number you input) x the amount of time you ride to give you your speed.

]]> http://www.cyclecomputerreview.com/news/how-do-you-install-cycling-computer-so-it-tells-precise-data-on-speed-and-travel/comment-page-1/#comment-2137 smitmeister_99 Sat, 19 May 2012 01:38:39 +0000 http://www.cyclecomputerreview.com/news/how-do-you-install-cycling-computer-so-it-tells-precise-data-on-speed-and-travel/#comment-2137 To program the computer follow instuctions,however almost all bike computers are preset to 26/1.75 standard mountain bike wheels right out of the box.You may also roll the bike foward 1 revolution,measure the distance and then enter the number that matches from the info book. oh and to above the magnet place ment makes no diff. as its still 1 revolution!!! To program the computer follow instuctions,however almost all bike computers are preset to 26/1.75 standard mountain bike wheels right out of the box.You may also roll the bike foward 1 revolution,measure the distance and then enter the number that matches from the info book. oh and to above the magnet place ment makes no diff. as its still 1 revolution!!!

]]> http://www.cyclecomputerreview.com/news/how-do-you-install-cycling-computer-so-it-tells-precise-data-on-speed-and-travel/comment-page-1/#comment-2136 uncleneal Sat, 19 May 2012 01:29:17 +0000 http://www.cyclecomputerreview.com/news/how-do-you-install-cycling-computer-so-it-tells-precise-data-on-speed-and-travel/#comment-2136 follow the instructions that came with the unit if you bought it used, throw it away and buy a new one follow the instructions that came with the unit

if you bought it used, throw it away and buy a new one

]]> http://www.cyclecomputerreview.com/news/what-is-the-polar-opposite-of-a-barrel-of-monkeys/comment-page-1/#comment-2135 scifuntubes Thu, 17 May 2012 08:59:46 +0000 http://www.cyclecomputerreview.com/news/what-is-the-polar-opposite-of-a-barrel-of-monkeys/#comment-2135 tub of turtles tub of turtles

]]> http://www.cyclecomputerreview.com/news/what-is-the-polar-opposite-of-a-barrel-of-monkeys/comment-page-1/#comment-2134 wushuboy001 Thu, 17 May 2012 08:13:36 +0000 http://www.cyclecomputerreview.com/news/what-is-the-polar-opposite-of-a-barrel-of-monkeys/#comment-2134 I would say the polar opposite of a barrel full of monkeys is a very cold barrel full of ice monkeys. Its gotta be ice monkeys to survive in the polar climate. I think the polar opposite of cinnamon is fart. I would say the polar opposite of a barrel full of monkeys is a very cold barrel full of ice monkeys. Its gotta be ice monkeys to survive in the polar climate.
I think the polar opposite of cinnamon is fart.

]]> http://www.cyclecomputerreview.com/news/what-is-the-polar-opposite-of-a-barrel-of-monkeys/comment-page-1/#comment-2133 T R Thu, 17 May 2012 07:35:23 +0000 http://www.cyclecomputerreview.com/news/what-is-the-polar-opposite-of-a-barrel-of-monkeys/#comment-2133 A paucity of pandas, obviously! A paucity of pandas, obviously!

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