RoadBikeReview.com's Forum Archives - General


Archive Home >> General(1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 )


Cyclometers...how far up(/down) on fork?(5 posts)

Cyclometers...how far up(/down) on fork?Kunfoochi
Dec 1, 2002 1:47 PM
I got a new Cateye Estrale 2, and there is nothing in the instruction manual saying where on the fork to mount the sensor(and hence how far up on the spoke the magnet should go)....I ended up putting it 3 or 4 inches from the rim, but I don't know if this is correct.

Any suggestions?

Thanks
re: wherever it fits best for you...Akirasho
Dec 1, 2002 2:24 PM
... mounting near the rim leaves less wire (assuming a wired unit) to run along the fork and can be aesthetically pleasing... but putting the magnet near the rim increases it's centrifugal weight (albeit a small amount).

... mounting near the hub alleviates the abovementioned weight thingy, but depending on your mounting skillz (hiding the wire with black, clear or colored to match your fork/frame electrical tape) may not be as pleasing to the eye.

... from a speed POV... it doesn't matter since the computer is measuring RPM over time to compute said (one revolution at the rim is the same as one revolution at the hub, albeit, the rim mount has a higher angular velocity (I think)).

... either way, you'll have to make sure the sensor and magnet are in close enuff proximity to signal the head unit (a tad easier on some sensors mounted near the hub... but not all (my wireless Flight Deck mounts near the rim and looks kewl) while remaining clear enuff for wheel changes (no biggie).

We abide.

Remain In Light.

Be the bike.
re: wherever it fits best for you...Kunfoochi
Dec 1, 2002 3:13 PM
Great explanation, thanks!
My preference is near the hubbrider
Dec 2, 2002 9:42 AM
I've had some problems with the single-magnet types when mounting them away from the hub. Wheels deflections (though small) can affect the pick-up of the magnet as it passes the sensor. Also, as you get away from the hub, the magnet passes teh sensor faster, increasing the chances of it missing.

To solve all that, I've stuck with Avocets.
re: Cyclometers...how far up(/down) on fork?moo2
Dec 2, 2002 12:48 PM
Mount it as close to the hub as possible/practical.

As another poster eluded, this will have the least angular velocity of any location.

This is important when you realize that the magnet sensor is just a reed switch that has a certaiin latency. It has a maximum rate at that it can open and close reliably.

By mounting the magnet/snesor down near the hub, you effectively slow the pass of the magnet by the sensor, thus giving the sensor more time to "react" and send a pulse up to the computer's head unit.

This will make your computer more reliable and accurate. For more info, check out http://sheldonbrown.com/cyclecomputer_installation.html