Reed switch and magnet
1. Why do you recommend fitting the reed switch to the
The "recommended" location
for the reed switch is the rear wheel purely and simply because it's easier
on most bikes, and will perform reliably
There's no technical problem at all with fitting to the
front, though you will need extra length of wiring, and the routing the wiring
is a little trickier than when fitted to the rear wheel.
There are some bikes where a rear wheel fitment is not possible, or very
difficult - mainly single-sided swingarm machines like the Honda VFR, some
Triumph's, Aprilia's and Ducati's
Most bikes have "solid" rear discs, as opposed to
"floating" discs which are normally found on the front.
The carriers and bolts on floating discs run far cooler
than those of solid discs
Magnets can lose their magnetism when subjected to
excessive heat, which can lead to a loss of the signal
The solid rear disc carrier and disc bolts can get very hot
when used on the track or coming down mountain passes.
If you ride in these environments, then it may be better
to consider fitting the reed switch and magnet to the front wheel
2. I already have a Sigma bicycle computer reed switch and
magnet fitted to the front wheel. Can I tap into this wiring for the
You can use the Sigma's magnet,
but not share the wiring. The reason is that the
Sigma can upset the PRO-OILER - and vice versa.
Whatever, you will still need to
check that you have a good signal!
3. Does the position of the reed switch matter?
As long as it works, not
fix the reed switch temporarily in your intended location (eg.
with double-sided tape), and test for the signal
But... there's always a
The one real no-go is lengthwise relative to the magnet
(so the path of the magnet is along the length of the reed switch). This can generate multiple signals
Even technically "undesirable" locations (like
end-on to the magnet, pointing at the magnet's path like a proximity sensor)
can work well. You just need to test it.
It's best not to place the reed switch on a surface
which moves relative to the magnet, for example on the swing-arm itself.
you adjust the chain, the magnet may move out of range,
resulting in a loss of signal. Having said this, if you do mount the switch on
the swing-arm, just check for a signal when you have adjusted the chain - or
use a bracket with an elongated hole
as you are using a PRO-OILER, you will not need to adjust your chain very
It's worth putting some thought into placement of the
reed switch - there will often be more than one workable location.
Think about how vulnerable the switch will
be at wheel-change time. This
is a major factor in deciding on a location
Look at Tips and Tricks
and Troubleshooting for more reed
switch and magnet information
4. Does the position of the reed switch matter?
The magnet supplied is a
powerful neodymium 6mm dia x 4mm high button (or 5 x 4mm depending on the bike
Many bikes have M8 allen
head brake disc fixing bolts, and the ideal is to fit the magnet into the bolt
The magnet will stay in the bolt head without need for
any form of glue
To remove the magnet from the bolt head, use a
magnetized screwdriver or another magnet
If your bike does not
have M8 allen disc fixing bolts:
If it has M6 allen bolts (and you did not specify which
bike you have at the time of ordering), PRO-OILER will post you a smaller 5x4mm
magnet free of charge
If it uses conventional hexagon set-bolts, consider
swapping one of the bolts for an allen disc mounting bolt.
There is no technical
problem with this, however...
Make sure there is enough clearance - allen bolts usually have taller heads!
Otherwise, glue the magnet to an aluminium
bracket fixed by a disc bolt
not glue the magnet directly to the brake rotor!
There is no glue in
existence that can withstand the heat generated by a solid brake rotor. However,
you may be able to glue the magnet to the disc carrier of a floating disc, as
these stay much cooler.