Anyone who spends a great deal of time in the outdoors usually ends up alone much of the time. Being alone in remote places and participating in a motion sport like cycling is a reasonably serious risk. Cell phones may not work. Who knows where you rode that day? Where would search and rescue look for you?
There are sophisticated products like the SPOT locator device. This is slick but is somewhat expensive for the average Joe out for a ride.
There is another option that, while it does not locate you and broadcast your position, it does identify you and supply crucial info for emergency contact numbers, medical issues such as allergies, etc, and will even send an email to people stating where you plan on riding that day and when you will return, etc.
All that for a few bucks. Xtreme Sports ID has a motto: "Never Go Out Alone". Their product is a simple ID bracelet like the ones you see all over the wrists of people, the colored rubbery ones like this:
The bracelet has an individual serial number on it that links you to an online database of your info for contacts, doctors name, etc. It will also allow you to send a pre-ride email to select addresses that details your plans in case you drop out of site. As well, there is a phone number option that allows the rescuer to dial a number, enter your bracelet's serial number, and get interactive text to voice info on you with no need for an internet connection.
If you are found and are unable to respond to questions or are unconscious or, well, dead....there, I said it, your identity and contact info will be readily available.
All this for eight bucks per bracelet which includes one year of the web and phone service and it is five dollars per year after that if you wish to continue.
I got mine. Cool deal for $8.00.
"Please don't let me die."
4 years ago