Mounting digital bike speedo/computer ?

[ADK46R]

Has anyone tried using a bicycle-type digital speedometer/computer on a BMW R1100-S or similar bike with cast wheels? The kind I have in mind are the type that use a small magnet mounted on the wheel(usually the front), with the pickup unit adjacent to it (usually on the front fork). Possible choices are the Sigma or maybe a Cateye. I've used the Sigma system on my KLR's but on the BMW - with cast wheels instead of spoked, mounting the magnet is the problem... where can I put it? The "spokes" of the cast wheel are too far from the front fork to make that an option - magnet needs to be < .25 inches from the pickup unit. So, has anyone a solution? Anyone using a digital speedo/computer on a bike with cast wheels?

[feisty]

I put one on my vtr years ago. I found a nice little slot just inside the sprocket area of the hub. Then filed down a magnet of an old fridge magnet so that it was a tight fit then glued it in place with arildite. The sensor unit was glued to the underside of the swingarm.
The issue with the distance will only be an issue if you use the supplied micro magnet IMO.

[Droptarotter]

I have used a Sigma on my KTM dirt bike since it was new.
I used silicone to attach the magnet to the disc and the pick up was attached with zip ties.
The Sigma computers are great for this.......I used a wired computer, but had to extend the wire. The wire was installed by running it along the front brake hoses and onto the handlebars.
It was then attached with the supplied o-ring.

Calibration was simple.

Cheers

[BumbleBeemer36]

Don't know why but the Trek wireless I put on my TT500 doesn't work. The speed goes 52,37,53,14, etc. It seems like the high number is correct but the display is erractic - constantly changing so I can't see what that high number is most of the time.

Maybe it's getting inference from the ignition but I'm going to a RAM mount for my Garmin instead.

My speedo is so far off on my R11S that I use the Garmin on it every time I ride.

[knnshallwminded]

i nave used a panoram bike speedo for 6yrs.dead accurate according to garmin.super glue the magnet to the inside of rotor toward the hub.its on my air head with honda wheels and front end.hope this helps kenny