https://www.mec.ca/AST/ShopMEC/Electr...rex-30-gps.jsp

VS

https://www.mec.ca/AST/ShopMEC/Electr...rex-20-gps.jsp

So far as I can see the main differences are the barometric altimeter and the electronic compass. Any other reasons to get one over the other? Is the $100 worth it? Is a barometric altimeter nice to have? Which one would you get, and why?

Thanks,

C

I think the 20 doesn't support ANT+ so no heart rate or dedicated speed/cadence sensor.

I just bought the 20, I couldn't convince myself that the extra $100 was worth it. I didn't see where the more accurate compass and altitude of the 30 was worth much for my type of riding (road, rail trail, etc). Perhaps mountain biking might have more applications where there aren't well defined roads/trails, and if you also plan to use the unit for hiking then I would definitely consider the 30. As for the ANT+ capabilities that would be nice, but honestly I ride for fun and not exercise, on the few rare occasions that I want heart rate info I'll wear my strap and watch thing that I use for the gym.

The barometric altimeter is a nice gadget, but useless on a bike. As you travel, weather systems change (ergo the pressure changes) which gives false altitude readings. To obtain any form of accuracy you must calibrate, which doesn't last for long (because weather is unstable). These errors get compounded when climbing. Same thing with the e compass, it only functions when you aren't moving. Once moving the satellite system takes over.

Thanks guys, super info.

I'm getting the 20.

I've been thinking of getting a 20 myself. Mostly want it so I can map the dirt/gravel trails I find while riding, so I can return to them and also try to link them all into 1 ride. Is it good for that use?

the recorded track was one of the reasons I bought mine, I bought an Etrex Vista HCx on clearout. First it was to replace a cycle computer that would reset after 500km (no good for rando rides), and the trip computer screen gives a better choice of data. But the best part is after you sync to either garmin connect or ridewithgps, you get a nice visual overlay on an actual map of where you went. Then all your rides, regardless of bike that day, are recorded in the cloud. I paid $150, considering the Etrex legend I had bought 8 yrs ago was $180, if was a steal.

Its very useful for measuring grades accurately, so its particularly well suited to bikes. We all hate those 1% false flats!

Yes I do have some crazy elevation plots riding through storm fronts but generally when I get home I'm reading within a few m of where I started.

Now if only Garmin could write a firmware update for eTrex 30, allowing it to display the current grade! Current version only supports the "glide ratio", which is the inverse of the current grade. So, if you're going up 8% grade, it will say "12:1". A 3.5% grade is "29:1". You get used to doing mental conversions after a while, but it would still be nice to see the data in the correct form right away.

Ditto on need for Garmin to produce a firmware update for the eTrex allowing it to display the current grade. Until then does anyone have a formula or chart to convert glide ratio to current grade?