[This tip is courtesy of Ian Boehm via the Audax Australia Checkpoint magazine No. 59]

Almost all cadence sensor systems rely on a magnet attached to your crank activating a reed relay inside the anonymous black box on the boom or chainstay of your chosen conveyance.

The average cadence magnet adorning your left crank is hardly the prettiest accessory on your bike. A more elegant and easily installed solution is to put a disk magnet on the crank end of your steel pedal shaft.

The accompanying photos best illustrate the solution.

Before you wield the side cutters on the cable ties holding your existing crank magnet, ensure that you have enough real estate on your chainstay/boom and, if appropriate, enough cable to relocate your sensor to mate with the pedal shaft of your crank. Having done thatnow source your magnet. Oh there’s one more step.

If you have expensive pedals they may have titanium axles.
Ti is a non-magnetic metal so you will need to choose between using, say, double sided sticky tape or keeping youexisting magnet system.


The magnet shown came from a dead computer CD-ROM drive but, if you’d rather not rat the neighbourhood nature strips for suitable PCs, you can buy suitable inexpensive magnets online.

Deal Extreme (www.dx.com) has suitable doovers (Deal Extreme catalogue numbers of suitable magnets are:

  • 233616 12.5 mm x 9 pieces U$3.80 and
  • 236650 12 mm x 80 pieces U$9.90).

Search for “round magnet” rather than disk magnet. There will be other on line sources. Some resourceful sellers want several dollars each for suitable devices.

The right diameter is about 12 mm. Anything larger might be difficult to remove once it is in place. The one pictured is about 11.5 mm wide.

Audax members, being resourceful people, will surely find uses for the excess magnets.

Similar Posts