Hello, welcome to the Weekly Mailbag. I'm Ray, from DCRainmaker. com. If you've ever searched for reviews on sports technology - you've probably come across my site. I write about my triathlon/running training in general, along with sports technology and whatever else seems interesting to me. I started the Weekly Mailbag series earlier this spring as an opportunity to share some of the answers of the many e-mailed questions I get each week.

If you enjoy what you find here, then feel free to click the links to find even more in depth information on each topic. And if you have any questions, you can always e-mail me directly. Thanks for reading!

1) Connecting multiple ANT+ units to a single HR strap
2) Screen protectors for Forerunner devices
3) HED3 wheel speed sensor magnet options?

Question #1: Connecting multiple ANT+ units to a single HR strap
From Christian-

"I'm a rock climber and now I'm starting with trail running looking forward to complete a 100 mile ultra!

I need a watch to track my training, but as the Forerunners do not have barometric altimeters I'm planning to buy the Edge 800 + FR60. With the Edge I can track my workout and get barometric altimeter information and with the FR60 I can see HR + pacing on my wrist. Can I use both watches at the same time?"

Yes, absolutely. With ANT+, it's a one to many relationship. This means that you can have a dozen receiving units (i.e. Edge's, Forerunners - even cell phones) connected to a single ANT+ accessory, such as a heart rate strap. In fact, when I'm testing products I often do this. It's not uncommon for me to be testing 2-3 devices concurrently during a run/ride that have ANT+ technologies. In doing so I only wear a single heart rate strap, or have a single power meter or cadence sensor on my bike. Yet all the devices can receive information from that single accessory and record that data.

The combination of the Edge 800 and the Forerunner 60 is very popular. With the Edge 800's mapping capabilities, especially the new Birdseye satellite imagery features, it offers a number of features that folks doing adventure or off-road racing find useful. While the FR60 has virtually unlimited battery life (1 year), making it ideal for cases where battery life is an issue (i.e. Ultras). Also of note is that just two weeks ago the Edge 800 got a new firmware update that allowed 1-second recording for all recording modes, as opposed to previously with just a power meter.

Question #2: Screen protectors for Forerunner devices
From Kent-

"I just bought the FR305? Is there a screen protector you can recommend?"

I'm not sure I'd look to put a screen protector on the FR305 to be honest. I've only seen a handful of cases where the FR305 screen broke, and all of them were the result of blunt force trauma.The FR305 has a raised bezel about the screen that protects it from falls that would directly hit the screen. In the case of a fall so brutal that the outer case is broke, it's unlikely a screen protector would assist much. The FR310XT's on the other hand… that's a different story.

For those curious about protection for the FR310XT's crack-prone glass screen, one option if you don't mind the lack of fashionable elegancy is to make a very small silicon caulking bead/line around the upper rim of the watch. This would protect the unit in the event of a fall resulting in direct screen glass to concrete contact. It's not perfect, but it is an option - one that I know some folks have employed with success.

Question #3: HED3 wheel speed sensor magnet options?
From Josh-

"I just bought a pair of HED3 wheels and I'm wondering what's the best way to mount a spoke magnet for my Garmin sensor?"

Hi Josh. Having the same wheels, it can be a bit tricky. As you know, the HED3s utilize a tri-spoke design with three large carbon "blade" spokes that are about 3-4" in width. This makes it far too large for your average spoke magnet that wraps around the spoke itself and screws tight.

The solution though is just a couple bucks away. Cateye makes a magnet for composite wheels that uses a very small zip tie instead. This works perfectly with your standard Garmin GSC-10 cadence sensor (or any other speed sensor out there). It only takes a second to install and then you'll just simply adjust the arm on your GSC-10 to be within normal operating distance of the spoke.

You can pickup the magnet a variety of places, including directly on Cateye's own site. The part number is 169-9760 and is officially called the "Cateye wheel magnet for composite wheels."

Recent Mailbags:

Weekly Mailbag - April 26th, 2011
- Extra long detailed comparison between Garmin
FR310XT and FR610

Weekly Mailbag - April 19th, 2011:
- Bluetooth Heart Rate Strap Monitors
- ANT+ Cell Phone Client and App Options
- Review of smartphone clients

Weekly Mailbag - April 4th, 2011:
- Taking the Forerunner to the pool?
- Best bet for trail running watch with altitude?
- Auto-Pause, Running and Races (and why your distance might be short)

You can find all past Slowtwitch Mailbags here, and all prior ones here.

[Editor's note: our capable editor-at-large for electronics Ray Maker is the publisher of the online sports tech blog DC Rainmaker, one of the top-ranked sites by Google for extremely in-depth reviews of advanced GPS and Heart Rate Monitors for triathlon, cycling, and running.]