Different models of Sigma bicycle computers are used because Sigma brand read up
to 300 kph. Mine is a BC 800. I have mounted it next to the clutch master cylinder.
I have used the 'rear wheel mounting kit' ($13) which is the same as the one included
except that it has a longer feed wire. My magnet is mounted on the inner supports of the
disc.
Some people have used the standard length feed wire and epoxied the magnet (or any magnet)
to the wheel rim with the sensor epoxied inside the fork leg fairly high up.
When checking the speedo out you need to get a few movements of the magnet past the sensor
before it will read so support the wheel off the ground and give it a few spins.
I trimmed half the plastic off the magnet and epoxy glued it to one of the inner spokes of the disc and then cable tied it. You probably do not need the cable ties but it gives more confidence. I did not use the rubber bands for the magnet or sensor mount at all. I epoxy glued the sensor in position on the inner side of the fork leg where the yellow mark is. The feed cable is cable tied to the brake line and run up to the display.
