Mounting the Sigma Sport BCxxx Trip Computer
I do my very best to tell the correct things, but of course I can give you no warranty!
The first thing you have to do is to find a place to mount the display. I mounted
it on the 
left side of the handle
bar next to the mirror, but I saw people who
had mounted it right in the middle of the handle bar, and had put a tiny lamp over
it on the crossbar. A good idea, but I think you can't see it anymore if you are
using a big tank bag...
Then you have to elongate the lead from transmitter to the display carrier by, let
me say, 20-30 cm. Check it out. Don't forget to isolate the connections.
You have to mount three things: the display carrier, the transmitter
and the magnet. The display carrier and the transmitter are connected by a lead,
the magnet is a single part you would normally mount on a spoke, but on a motorbike,
you have to mount it somewhere else, because the distance between magnet and transmitter
may not be greater than 5 mm (but don't let it be smaller than 2 mmm!). On a Transalp the best place to mount the magnet is
the black plastic disk inside the brake rotor. To compensate the angle of, let me
say, 20 deg this plastic disk has towards the axe, put a little piece of polystyrene
under the magnet. I fixed this construction with hot glue. A first trial using
silicone didn't work very well. Be sure to mount the magnet on the opposite of
the tire valve, then you may not need so much balancing weight. And it's a good
idea to mount it, when you're about to change the front tire... The transmitter you have to mount on the lower part of
the left fork tube. There is a 
triangular shaped strengthening towards the axe
bearing; file a little triangular into this strengthening (2*2 mm) and mount the
transmitter using lead fixing stripes or something like that. The transmitter should
be mounted by an angle of ca. 40-45 deg looking forward, otherwise the distance
between the magnet and the transmitter would be too small. Check it by driving. If
the display of the computer is significantly different to the one of the stock
speedometer, something is wrong. A difference of 5 km/h is normal.
For adjusting the display refer to the manual; as circumference of the front
wheel I took 2155 mm; it's a pretty good average value between a new and a worn
tire, I think. To check the calibration, go and find some accurate mileage signs
on some highway. F.e., those small blue km-signs on a German autobahn ... Reset
the odo at one of those signs, go for 10 km with constant speed, and compare the
number on the sign with the odo display. If there's a difference, you may
re-calibrate your speedo by using the formula new_circumference = real_km * old_circumference / displayed_km.
left side of the handle
bar next to the mirror, but I saw people who
had mounted it right in the middle of the handle bar, and had put a tiny lamp over
it on the crossbar. A good idea, but I think you can't see it anymore if you are
using a big tank bag...
triangular shaped strengthening towards the axe
bearing; file a little triangular into this strengthening (2*2 mm) and mount the
transmitter using lead fixing stripes or something like that. The transmitter should
be mounted by an angle of ca. 40-45 deg looking forward, otherwise the distance
between the magnet and the transmitter would be too small. Check it by driving. If
the display of the computer is significantly different to the one of the stock
speedometer, something is wrong. A difference of 5 km/h is normal.