Category: cycling

I’m apparently on a quest to find ideal neodymium magnets for triggering the cadence side of ANT+ speed/cadence sensors such as the Garmin GSC-10 and Wahoo Cycling Speed/Cadence Sensor. I’d previously tried wide/thin (10mm wide, various thickness) magnets such as the one seen here on the Salsa El Mariachi Ti which sit on the end of the pedal spindle. This works well on the El Mariachi Ti where the crank boot supports it from the side, but on bare cranks it’s not difficult to knock the magnet off. My friend Jeremy has lost at least one magnet this way.

A few days ago I received some 8mm x 10mm (diameter x height) neodymium magnet cylinders via eBay and these seem like an even better solution. On Crank Brothers pedals with 8mm hex sockets in the end of the spindle, these magnets slide snugly into the 8mm hole, with a bit over 2mm poking out. This works great for triggering the reed switch inside the cadence sensor, and unlike other magnets which simply stuck to the end of the spindle, roughly 75% of the magnet is inside of the pedal so it won’t be possible to knock this one off.

Removing the magnet as needed is pretty easy, too. Because there is no flat surface at the bottom of the hex socket the magnet is relatively easy to remove. It can easily be pulled out with another magnet, by sticking a flat piece of steel to the top, or grasped firmly (say, with pliers or some strong finger tips) and slid out. While getting to this fastener outside of a shop isn’t usually needed, it’s good to have the option.

After ~2 years (and maybe four months of need) I finally replaced the pads on my daytime helmet†, a Giro Xar. I’ve been quite happy with this helmet, and it’s done well for me, but the soft pads inside were soundly compacted and some parts were starting to delaminate. This meant that there would be large lumps inside the helmet if I didn’t put it on very carefully.

At $4.99/set for the pads I should have done this a while ago. The replacement is as simple as pulling out the old pads and sticking the new ones to the velcro.

† At night I wear my old helmet, a Giro Phase. This one isn’t quite as comfortable as the Xar, so I keep a light mount on top and use it mostly at night. It’s also a backup in case something happens to the Xar.

The Salsa Vaya (and hopefully the forthcoming Motorless City bike) has the rear disc brake cable run along the top of the chain stay, which means the Garmin GSC-10 (Speed/Cadence Bike Sensor) cannot cleanly fit on the bike (photo). To work around this I picked up the Wahoo Cycling Speed/Cadence Sensor (a compatible ANT+ device) and thus far it seems like it’ll work just fine. I had no problems hanging both sensors below the chainstay, and my Garmin Edge 510 quickly picked up the sensor and was able to get both wheel rotation and cadence data from it.

This setup isn’t as attractive as Garmin’s single unit, and the need to double the cable back on itself looks a bit sloppy, but it does offer more flexibility and overall it should work out fine. I was also a bit disappointed that it doesn’t feature a Garmin unit-like test button/LED which makes setup super easy. It’s a bit higher priced than the Garmin sensor, so it’d be nice if it was at least identical feature-wise. It’s also a bit awkward how the entire sensor body needs to be pivoted in towards the spokes instead of a small/discrete arm, but I do think it’ll work out fine.

Since this was a test mounting I was a bit careless with the cable ties and didn’t peel the adhesive pads off of the cadence sensor, making for sloppy work. I intend to leave this (with its ugly, temporary fittings) in place for a month or so, and then hopefully after that it’ll be in place on the Motorless City bike.