Computer Install Question on LHT - Placement on Spoke

[mkwdrs]

I realize this is a dumb question, but I am dumb so I qualify to ask it.

When you install a bike computer, you have to enter the size of the tires.  My LHT is 26 x 1.5 tires.

Warming, here comes the dumb question . . . I realize the sensor has to be close to the thing-a-ma-giggy to get a reading

Will the computer give different readings based on where the sensor is installed (I'm talking closer to the hub versus closer to the rim)?  Meaning, if I install the sensor and ride.  Later on, I move the sensor down 3 inches.  Will the readings be different?

[jsieber]

Moving the sensor and magnet up or down along the spoke and fork leg should not make any difference as the entire length of the spoke will always be rotating at the same speed/spot. As long as the wheel size does not change you should be good.

[scott.laughlin]

The axle turns in sync with the rim and so do the spokes.   

[DaveB]

The only possible problem is if the magnet and pick-up are mounted very close to the rim.  The linear speed of the magnet past the pick-up can be high enough that the pick-up doesn't catch the signal at high bike speeds.  Some computers are sensitive to this and others aren't.  I usally mount the magnet and pick-up about 1/3 of the way out from the hub or about where the third spoke cross occurs on 32H, 3X wheels.

As the others have noted, the theoretical accuracy is the same no matter how far out the magnet is located.  One pulse per revolution is the same for all points on the spoke.   

[paddleboy17]

The shape of the pick up sensor usually dictates where on the fork it must be mounted.  I position the magnet to work with the sensor.

[DaveB]

The shape of the pick up sensor usually dictates where on the fork it must be mounted.  I position the magnet to work with the sensor.

The recent Cateye cyclometers I'm familiar with have pickup mounts that are useable anywhere along the length of the fork blade. 

[paddleboy17]

The recent Cateye cyclometers I'm familiar with have pickup mounts that are useable anywhere along the length of the fork blade. 

Great, but I doubt there is enough clearance to put it at the hub.  You probably have to for 1/3rd of the way out from the hub to get enough clearance.  I also have a harness another vendor that is a big honking thing, and by the time I get enough clearance between the fork and the spokes, it is 2/3rds of the way out.

As was previously mentioned, anywhere on the spoke could work.  The sweet spot is probably in the middle.

[DaveB]

Great, but I doubt there is enough clearance to put it at the hub.  You probably have to for 1/3rd of the way out from the hub to get enough clearance. 

Depends on the magnet you use.  If you use one of the screw-backed "button" type that sticks out of the spoke a bit, yes you have to mount it a few inches up from the hub.  If you use one of the thin plastic "clam-shell" designs, you could mount it quite close to the hub.  

Really, there is no reason to crowd the hub and 1/3 to 1/2 way out is as good a location as any.