|
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
New Computer Installation
I have recently purchased a new CatEye computer for my bike.
In the past the computer that I have installed stated in the instructions that the magnet should be placed as close to the axle as possible. With my new computer the sensor/magnet is placed about midway on the fork. Nothing in the instructions state how high or low on the fork the sensor should go. If the sensor is placed at a random height, won't this throw off the accuracy of the computer? If the magnet is not placed as close to the axle as possible, won't this throw off the balance of the wheel? |
Ads |
#2
|
|||
|
|||
New Computer Installation
Yme wrote:
I have recently purchased a new CatEye computer for my bike. In the past the computer that I have installed stated in the instructions that the magnet should be placed as close to the axle as possible. With my new computer the sensor/magnet is placed about midway on the fork. Nothing in the instructions state how high or low on the fork the sensor should go. If the sensor is placed at a random height, won't this throw off the accuracy of the computer? If the magnet is not placed as close to the axle as possible, won't this throw off the balance of the wheel? No. Lou -- Posted by news://news.nb.nu (http://www.nb.nu) |
#3
|
|||
|
|||
New Computer Installation
Yme wrote:
I have recently purchased a new CatEye computer for my bike. In the past the computer that I have installed stated in the instructions that the magnet should be placed as close to the axle as possible. With my new computer the sensor/magnet is placed about midway on the fork. Nothing in the instructions state how high or low on the fork the sensor should go. If the sensor is placed at a random height, won't this throw off the accuracy of the computer? If the magnet is not placed as close to the axle as possible, won't this throw off the balance of the wheel? Let me expand a bit. The computer works as a counter - not a velocity detector. The wheel goes once around at the hub as well as the rim with neither part of the wheel having more revolutions than any other part of the wheel. The computer calculates number of wheel revolutions over time. So the placement of the magnet / pickup isn't relevant to the measurement. |
#4
|
|||
|
|||
New Computer Installation
Yme wrote:
I have recently purchased a new CatEye computer for my bike. In the past the computer that I have installed stated in the instructions that the magnet should be placed as close to the axle as possible. With my new computer the sensor/magnet is placed about midway on the fork. Nothing in the instructions state how high or low on the fork the sensor should go. If the sensor is placed at a random height, won't this throw off the accuracy of the computer? If the magnet is not placed as close to the axle as possible, won't this throw off the balance of the wheel? Not at all. Try sticking something twice as heavy near the magnet & test ride it. Cateyes seem best just below your caliper. Inside the sensor are two reeds. The magnet pulls the steel one to touch the copper one, signalling "one iteration" to the chip/clock. New in the the box, it's preprogrammed for a 700-23. You can change that value using either the supplied lookup table or riding over a paint spot on a sidewalk, measuring dot-to-dot and entering that exact wheel travel. (decimal meters, either as 2XXX or 2XX; depends on model) It matters not where the sensor mounts - it still increments "one iteration". -- Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971 |
#5
|
|||
|
|||
New Computer Installation
|
#7
|
|||
|
|||
New Computer Installation
On Fri, 04 May 2007 07:46:00 -0400, Barnard Frederick wrote:
If we know the distance and the amount of time it took to travel that distance, we can calculate the speed. So the sensor can be place anywhere on the fork with out compromising speed or distance traveled. Makes perfect sense know. In article , says... I have recently purchased a new CatEye computer for my bike. In the past the computer that I have installed stated in the instructions that the magnet should be placed as close to the axle as possible. With my new computer the sensor/magnet is placed about midway on the fork. Nothing in the instructions state how high or low on the fork the sensor should go. If the sensor is placed at a random height, won't this throw off the accuracy of the computer? If the magnet is not placed as close to the axle as possible, won't this throw off the balance of the wheel? One wheel revolution is still one wheel revolution no matter where the sensor and magnet are. However, the placement of the sensor/magnet has nothing to do with accuracy, but with how fast the magnet passes the sensor. If the magnet passes the sensor too quickly, it may not have time to register. That's why most instructions I have seen recommend placing the sensor lower on the fork and closer to the hub. I have used Cateye and Planet Bike computers and both of them work over a fairly wide range of positions. The Cateye magnet is very small and light. I even bought spares for my Planet Bike computers for that reason. Bike wheels don't spin fast enough for wheel balance to be much of a problem. |
#8
|
|||
|
|||
New Computer Installation
Yme wrote:
On Fri, 04 May 2007 07:46:00 -0400, Barnard Frederick wrote: If we know the distance and the amount of time it took to travel that distance, we can calculate the speed. So the sensor can be place anywhere on the fork with out compromising speed or distance traveled. Makes perfect sense know. That wasn't to hard was it? Put two magnets on your wheel and you go twice as fast. It's that easy. ;-) Lou |
#9
|
|||
|
|||
New Computer Installation
says...
I have recently purchased a new CatEye computer for my bike. In the past the computer that I have installed stated in the instructions that the magnet should be placed as close to the axle as possible. With my new computer the sensor/magnet is placed about midway on the fork. Nothing in the instructions state how high or low on the fork the sensor should go. If the sensor is placed at a random height, won't this throw off the accuracy of the computer? If the magnet is not placed as close to the axle as possible, won't this throw off the balance of the wheel? One wheel revolution is still one wheel revolution no matter where the sensor and magnet are. However, the placement of the sensor/magnet has nothing to do with accuracy, but with how fast the magnet passes the sensor. If the magnet passes the sensor too quickly, it may not have time to register. That's why most instructions I have seen recommend placing the sensor lower on the fork and closer to the hub. I have used Cateye and Planet Bike computers and both of them work over a fairly wide range of positions. The Cateye magnet is very small and light. I even bought spares for my Planet Bike computers for that reason. Bike wheels don't spin fast enough for wheel balance to be much of a problem. Barnard Frederick [Yme ] wrote: So the computer sensor counts the number of revolutions, this along with the wheel size is used to determine the distance traveled. This is similar to how a pedometer works. How does the computer determine the speed? I would assume how frequent the magnet passes the sensor. The speedometer would indicate a faster speed when sensor is closer to the axle, than when the sensor is faster away from the axle. It seems if the sensor is an inch too high or too low on the fork the speedometer would be off by less the 1 mile per hour probably less. This make sense now thanks for everyones explanation. The sensor increments "one iteration" to the chip- it matters not where the magnet is placed, it's still "one iteration". The chip has a crystal clock and a factor for wheel travel. That number may be adjusted to the actual travel of your wheel with you on your actual bike. -- Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971 |
#10
|
|||
|
|||
New Computer Installation
On May 3, 2:48 pm, Yme wrote:
I have recently purchased a new CatEye computer for my bike. In the past the computer that I have installed stated in the instructions that the magnet should be placed as close to the axle as possible. With my new computer the sensor/magnet is placed about midway on the fork. Nothing in the instructions state how high or low on the fork the sensor should go. If the sensor is placed at a random height, won't this throw off the accuracy of the computer? If the magnet is not placed as close to the axle as possible, won't this throw off the balance of the wheel? Hi there. Is your computer wireless? If your computer is wireless then higher on the fork the sensor/ transmitter is the better. This is due to the limited distance the transmitter can cover. My wireless transmitter is limited to 68 cm or about 7 inches. Many times erratic readings on a wireless computer can be elimininated by moving the sensor/transmitter as high on the fork as possible. The magnet can be attached to a spoke nipple. Cheers from Peter |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
BB installation issue | Keiron | Techniques | 3 | July 19th 06 08:12 AM |
Bar-end installation problem | JBAFromNY | Techniques | 15 | July 9th 06 02:25 AM |
XTR pad (v-brake) installation | Tom | Techniques | 1 | June 27th 05 04:24 AM |
Tufo installation | Goldy | Techniques | 11 | January 19th 05 02:09 AM |
STI Installation question | Jonathan Kaplan | Techniques | 5 | December 21st 03 02:29 PM |