The Science Of Attraction: Wheel Magnets

Icarus wheel magnet mounted on a SRAM S40 spoke.

 

It’s that little thingy on one of your spokes.  It tells the computer how fast the wheel is turning, and the computer calibrates that data into Speed and/or Cadence information for our inquisitive brains.  It is another one of those vital things on our bikes which most people take for granted.  Small, yes, but very, very important. 

Most of our encounters with the innocuous wheel magnet are noticing that it is indeed there after the shop puts it on for us with our new computer.  For others, the wheel magnet relationship is a bit more personal.  These riders have multiple wheelsets, and either moves their existing unit, or buys extras to negate the dreaded realization of a lack of computer data, because they forgot to put the magnet back on.  I used to be that guy.  Then, I got smart.

For all intents and purposes, the wheel magnet is just that – A simple magnet.  The best being Rare-Earth, they are either clipped on or have a circular thumb screw to firmly attach to a spoke.  Easy to put on and easy to line up, it is usually forgotten about once it is installed (or change wheelsets).  Well, after one too many times leaving home without it after changing wheels (I have three sets), I sought a better way to insure I had the data I needed.  So, I decided to try Icarus, bonded wheel magnets.

This perspective shows how thin the Icarus magnet is.  Yellow tape marked the "Sweet-Spot" for bonding.

While just about any good quality magnet will do, the Icarus magnets are made out of Nickel alloy specifically for bladed spokes, are extremely light, easy to mount, and once bonded to the spoke, are clean looking, and you will never leave home without a magnet again.  Recommended bonding agents are JB Weld or Tubular tire glues, however, I have discovered that a good quality Cyanoacrylate (Super-Glue) works just as well.

The most important things to do before mounting are to choose a spoke, clean it with alcohol, mark the position in-line with your computer pick-up (I use a Garmin 500 integrated Speed and Cadence sensor, and I used tape to mark the sweet-spot), apply your chosen bonding agent to the magnet and spoke, place, hold, and presto!  Permanent wheel magnet. 

I have been extremely pleased with the bonded magnets, as they are clean, light, reliable, permanent, and are darn near invisible.  However, to be fair, the only downside I see to this type of system is if that one particular spoke breaks, well, there goes your magnet, too.

Big, brand name wheelmaker magnets can sell for $10.00 or more.  Icarus wheel magnets can be found on Fleabay, I mean, eBay for around $5.00, and you get two (2) of them.

The Stats:

• Material: Nickel Alloy
• Weight: 0.0029 ounces
• Color: Silver
• Pick-Up Range: 0.25-0.75 inches
• Compatible with all brands of computer sensors, bladed spokes and disc wheels
• Extremely accurate