Not sure where to post this as I didn't see a bike gps section. I'm torn. Quick background on myself. Somewhat new to road but have been a mtb'r for years. I do about 50/50 lately as i'm 39 and don't have the time for all out trail rides and its easier to leave the house on a road bike with a new baby in the house. I want a clean readout of the basics (speed, cadence, distance, HR, time) and accurate GPS and elevation.

I've been using my iPhones w/ Strava for a while now but looking for a good dedicated GPS unit as the iPhone 7 plus is just too big for the handlebars. Here's what I've narrowed down:

Edge 520- I want but the whole money thing.

Polar m450 - I love everything about it including cost and DC rainmaker recommends it in his "budget" category but it does not have GLONASS... is GLONASS worth it?

Edge 25 - It gets good reviews, but it seems the mtbr crowd hates it since it doesn't do 1 second recording. Also doesn't have a barometer. If not for those things I would buy this one for size and cost.

Lezyne Super GPS- I was about to buy this as it seems to have it all, but under their support list for Ant+/BT it doesn't mention my speed / cadence sensor which is a Bontrager Duotrap.

Bryton 310 or 330 - The 310 gets good reviews but one really bad singletracks review on the 330 turned me off. I see some use it so if it is actually accurate this might be an option.

Anyways, thats all I got. I'm getting flustered with the options as the only one that seems to have it all is the 520, but the cost is hard to swallow. Any insights or help appreciated!

I have GLONASS turned off in my watch because I get fine GPS tracks without it and prefer the battery to last longer.

My Garmin 810 has US GPS only, no GLONASS. I've never noticed.

The 810 boots up and finds satellites pretty quick in my experience and tracks a road ride very close. or at least the track as viewed on Connect after the ride is dead on. I've seen repeated accuracy of about 6/10 of a mile per 100 as compared to a calibrated Cateye wireless cycling computer.

I had heard that riding in deep woods can make any GPS inaccurate, GPS or GLONASS, so I use a speed sensor on my mt. bike.

If you could find an 800 or 810 cheap enough, they work well as well. Or the Lezyne units are good deals.

Refurbished 800s are $170 with new case, new battery, and Garmin warranty.

The software is much more reliable than the 810 I crashed that within the first day, and lost data in the week I had it before returning it and getting an 810.

The 800 doesn't do bluetooth of any sort, always has left/menu/right showing on the bottom line so the text is a little smaller than the 810, and has bike profiles with individual odometers. Otherwise it's effectively the same as the 810.

I'd go with the Lezyne.
Lots of features, and good reviews. Having a young child, I think the ability to read text messages while riding would be very nice.

I wouldn't worry about the cadence sensor thing. That's the whole point of standards. Very likely Lezyne just hasn't specifically tested against a DuoTrap. They have tested the DuoTrap S and it was compatible.

If all else fails, buy from somewhere with a good return policy and return it if it doesn't work with your sensor.

Here's one persons experience with an early Lezyne and as posted on RoadBikeReview

"I have a Lezyne Super GPS (first Generation) that I bought last year. I was kind of in the same situation as the OP, needed a new computer but didn't really want to spend a lot. So it's functions/features and price appealed to me, plus I like all the other Lezyne stuff I have. But I would categorize the first generation Super GPS as just ok, have not used the new one yet so I don't know if it is any different. I also have a Wahoo RFLCT+ and in my opinion it is a better unit. The reason I needed another computer is I started doing Triathlons and phones aren't/weren't allowed on the course and since the RFLCT uses you smart phone as the brains I wasn't able to use it.

My issues with the Lezyne are/were, accuracy issues. I don't think those issues were with the GPS function as much as I think the computer lets the Speed/Cadence sensor over ride the GPS readings and that's where the inaccuracy happens. Once the ride has been uploaded to Strava the distance gets corrected by Strava, so that's what makes me think it's not the GPS sensors. I have been in contact with Lezyne's tech support, (which is almost nonexistent) a few times and their solution for any problem is do a factory reset which I have found can cause more issues. There have been a few times were I have had to do the reset multiple times just to get the unit to function. Once it is reset you then have to use the cumbersome menu system on the computer to set everything back up. I have found a "work around" for the accuracy issues and that is tell the GPS my tire size is much different than it is.

Which brings me to my next issue, I can't keep it connected to my iPhone so the incoming messages function doesn't work. That part is fine as I don't usually like that feature anyway but part of the iPhone connection is the upload to Strava and since I don't trust the finished ride report the computer gives me, (because of the previous inaccuracies), I like to upload it to Strava when done.

The last thing that bugs me is there is no way to have multiple bike profiles. So if you want 1 computer to use between different bikes the Lezyne's not for you.

I started to second guess my purchase of the Lezyne shortly after I got it, I should have just gone for my first choice of the Wahoo Element. I have had great results with my RFLCT+ and any issues I did have were acknowledged right away by Wahoo's Tech Support. There were a couple of times they even said we are working on the fix but it is not done yet so do this... as a temporary work around.

Now I have not tried the new Lezyne computers so some of the issues may have been fixed but don't expect much help from them if you have issues."

Most local bike shops sell the various Garmin's but my goodness do they have a significant markup over Amazon.
$283 is a rather good price on Amazon. Local shops range from $299-$399
$149 for the Lezyne Super GPS + $15 for mount.

While I agree that current cell phones are getting too large, old ones certainly are not. With a wife and 2 teenage kids, I have a *plethora* of very capable right-sized free GPS units that are largely disposable in the event that something happens to them. Every time a phone gets upgraded here, we end up the old units that are still perfectly functional.

I have 2 Galaxy S2's, 2-S3's 2-S4's and 2-S5's that are all surplus. I wiped them, installed Runtastic Roadbike Pro, and use those with a Delta XL Smartphone Caddy mounted to my stem cap. The maps layer doesn't work without a data connection, but everything else does and it just uploads the data to the server when I return to home via wifi. If I do want to have the maps working on my ride, I take my current phone in my pocket or frame bag and turn on data tethering so the one used as a GPS without a SIM card can connect to it.

I don't see the point in spending $200 or more for another dedicated gadget when I already have 8 of them that are probably as capable or more with the right software.

If you don't have one, ask around at work, I would bet there are lots of people who have surplus iPhones or Galaxy S#'s they would be willing to toss your way.

Cheers
TRJB

Thanks all. I may just buy the out front quad lock mount for now as money is tight. The iPhone 7 plus is big but one "plus" is it doubles as a zwift training screen on the trainer!

wait for a sale, got a garmin 520 kit with HR and cadence for $210 shipped

There are charities that will take those off your hands and get them to people in need. It's amazing how much difference a phone can make in a person's life.

That's what I use, a Quad Lock mount to hold my iphone 6S. It works well for me. I can't keep the screen on unless the ride is less than an hour. If the ride is longer, I use an external battery for the phone. I use the RideWithGPS app. It gives me more data than I could ask for.

i just picked up a Lezyne super GPS enhanced with the speed/cadence sensor and hr monitor. my necessities were to find something that would give me directions, should i need, from school to home as sometimes i tend to just end up places for no reason at all.

i ride on my bike trainer enough at night, so the speed cadence sensor was something i needed to keep track of the cadence and heart rate strap is a compliment to this.

i use an android phone so connectivity for me frankly with this unit was spotty at first. it kept disconnecting or not at all but i reset the unit and then it has been fine for the last two weeks.
the only thing that was weird is i decided to have it display calories and that figure seems completely wrong.

otherwise, i've been very happy with. works great and didn't give me much more than i needed like all the training options and stuff with the garmin and i got all the things that i needed. directions, speed/cadence,
also it came in that cool little box, with the forward mount as well as a stem mount and all, the charging cable, instructions for the HRM, the speed/cadence sensor and the unit itself.

you only get an hour with screen on? Seems really low for a 6s. Do you have a lot running at once?

It might be defective, and I might have abused it and thereby reduced the battery's capacity. I have to charge it in the middle of the day as well as overnight. I probably do run too many apps, and I clean up every so often, but I tend to run my machines hard.

The new Lezyne Enhanced GPS units would probably be the most suitable for the OP's needs, but boy-oh-boy, the new Wahoo ELEMNT BOLT is tres sweet...

OP, make sure your Bontrager DuoTrap is a newer model which has ANT+ and Bluetooth LE (4.0), the older DutoTraps were ANT+ only.

I get lost trying to use my smart phone for navigation because I can't get through a ride longer than four hours without running out of battery on my Galaxy S5 when I leave it in my pocket with the screen off and ridewithgps running only pulling it out to navigate. Running it off my dynamo isn't an option because it draws too much current.

I get wet trying to navigate in rain because the capacitive touch screen creates points of interest where rain drop hits and won't respond to touch.

My ANT+ devices don't work with my smart phone even though it has ANT+ hardware and it'd cost $800 for blue tooth replacements.

OTOH, I can go on 20 hour rides with my Garmin Edge 800, the resistive touch screen works in the rain, and it works fine with all my ANT+ devices.