Hello all. I have a newer bike that I am looking to add something to in order to track basic information from rides. I come from a time of just using basic cycle computers, many of which were even wired. There have been a lot of technological advances made in this area, and I am basically trying to decide if I should just go with a basic cycle computer or if I would be better served with a GPS unit with a wheel sensor? I'd love to hear some opinions on which is better and why.
Some basic GPS questions I have would be:
Is GPS w/ wheel sensor going to be as accurate as just the basic non GPS cycle computer? And vise versa.
With a GPS unit w/ wheel sensor, if you happen to not have a GPS signal where you are riding, would you still record the data and will it be as accurate?
Thanks for the help.
basic cyclocomputers were always effectively disposable to me. Failure rate after a few years was always high.
Garmins have been far more reliable for me (at least, when Garmin doesn't mess the product up with a bad firmware update, which happened to me on an Edge 705).
The best thing a GPS-enabled computer lets you do over a basic cyclocomputer is save data from each individual ride. You can associate photos with these files, which is fun for trip reports/memory lane sorts of stuff. The way the GPS data is stored lets you associate all kinds of other data that can be helpful for training purposes or mapping. I lean far more towards the mapping side than the training side.
IMO, a wheel sensor combined with your GPS computer is pretty essential for mtb purposes. Every turn gets cut a little short with GPS distance calculations. It's just the way it works. The sharper those turns are, the faster you take them, and the more of them that get packed into a given area, the more error in distance calculations you're going to get. A properly calibrated wheel sensor will override those GPS-derived distance calculations and give you much improved accuracy. The quality of your calibration will determine how much more accurate. These computers are much smarter than basic cyclocomputers and will often have an "auto" calibration mode that your cyclocomputer didn't have. It's easier to use, but it's not as accurate.
You're almost never going to completely lack a GPS signal in a given spot where you're riding. Exceptions I've encountered have been indoor bike parks like Ray's MTB and the old KY Mega Caverns underground bike park. The wheel sensor will still report distance in such cases because the GPS signal won't be penetrating through. You're best off in cases like that to just turn the GPS receiver off since you're doing an "indoor" ride. That mode was originally meant for use when you're on a trainer. But it works just as well when you're actually riding your bike indoors.
What you're most likely to encounter is the loss of accuracy from turns that I've already described. The next possibility is that you might have momentary loss of signal. Maybe you're down in a really deep canyon/valley with thick forest. Maybe you're doing a road ride and you ride through a tunnel. It's pretty much unheard of to be riding outside and never receive enough of a GPS signal that you don't get a position fix. I haven't encountered that situation since before 2000 when the government turned off selective availability.
When you lose GPS signal momentarily like that, the track can do all sorts of wacky stuff. Just before losing it completely and right after faintly picking it up again, it'll wander all over and could add a LOT of extra distance. With a wheel sensor, the track will still look wacky on the map, but the distances will still read correctly. If you're using the data for mapping purposes, you can manually edit the junk data out.
I HAVE had the problem where I traveled a large distance from home and my GPS took a very, very long time to get a position fix since it had to figure out new satellite positions. That's kindof inherent in how GPS receivers work. Travel a long distance or not turn the device on for a very long time and it has to receive extra data about which satellites are going to be visible and where it should find them. If you expect that sort of thing to occur, you can prep for it and let it do that work somewhere open where it's easy to receive those signals. Not starting that process until you're at the trailhead deep in the woods is going to make it take longer.
Phone tracking apps can work okay, sometimes. But there are limitations. Phones are massive these days and mounting one to your bars can be really irritating. The mount is also likely to be less secure. The phone will be more exposed to being hit by stuff. I've had to replace a couple Garmins after crashes. That's a whole lot less of a hassle than if that had been my phone. Phone hardware is extremely variable, also. The GPS hardware might be very good or very bad. You generally aren't going to know until you've used the GPS hardware in your phone for a bit and really pushed its limits. When it's bad, it can be very
bad. Phones also have highly variable battery life. Some do pretty well. Others can be absolutely awful. Phone screens can be iffy under damp, sweaty conditions. I've had some that were impossible to use under those conditions. My current one isn't so bad, but it's not great, either. My Garmin is an Edge 520 with physical buttons because of this. Don't have that option with phones. There are some sensors that work with phones, but not all apps can use them. So if you want to use any sensors while riding, you will have a limited selection of apps you can use with them. With a dedicated GPS computer, you'll have a LOT more flexibility with sensors.