Tandem Cycling - GPS bike computers

I was considering getting a GPS based bike computer. I notice that Garmin has models 205, 305, 605 & 705 "Edge" computers. Is anyone familiar with these? What do the 305, 605 & 705 buy you over the 205?

Back in April I picked up a 305 Edge from WalMart's online store for $250 shipped, or something like that...

You may recall this was a work-around to the problems we were having with her Polar S724i wireless and what seemed to be some type of RFI associated with the unpainted, all-carbon frame.

She's never bothered to use the HRM and I haven't fiddled with the GPS other than downloading to see what all the fuss is about, but as far as a basic computer goes it's pretty cool in that you get TONs of data that can be displayed all at one time and you eliminate the calibration and wheel sensor issues associated with most other bicycle computers. Therefore, she can move it from the tandem to her single bike with narry a concern or glitch.

Again, since I'm not using it I can't tell you what makes it better than a 205. However, the only thing I do know is that Debbie really likes it A LOT and, as we all know, a happy stoker goes a long way towards making a happy captain.

I have the Edge 205 and recently upgraded to the 305.....BOTH units work great.....no complaints.

sojourn - what does the 305 give you over the 205?

The 305 is a 205 with a few more bells. HRM, for one. The 605 and the 705 have the same relationship, a few more bells on the higher number. The difference between those and the old 205/305 is the color screen and associated maps.

I have been watching this market closely, but if you ask me, these are still bad user interfaces on good technology, all overpriced for what you get. The need to fork out more $$$ for better maps is a drawback.

I was on a ride yesterday where we got off course (I was the leader), I asked both my 305-using dudes to help find a particular route out, and they could not do it. Bad user interfaces on good technology.

We have a Garmin Edge 305 and we only use to record rides; we don't use it as a typical bike computer. We have Cateye Enduro 8's, front and rear, to view instanteous speed and trip distance. I really like the Garmin for downloading our rides to see our course, elevation profile and gain, average speed, and speed at various points in the ride. Most of the group rides we have done were guided by a ride leader who didn't pass out a map or cuesheet and I have used the Garmin download after these rides to see where we went so that we can repeat any rides we liked. I have used the heartrate monitor with the bike in a trainer, but I have never used it on the road. The display is very flexible and can be configured pretty much any way you want. The 305 has heartrate monitor, cadence, and an barometric altimeter that the 205 doesn't have. The 605 and 705 have color screens and mapping capability. Some people may find the GPS mapping handy but with my near vision being what it is, I couldn't use the small screens that these things have.

I have been watching this market closely, but if you ask me, these are still bad user interfaces on good technology, all overpriced for what you get. The need to fork out more $$$ for better maps is a drawback.

I was on a ride yesterday where we got off course (I was the leader), I asked both my 305-using dudes to help find a particular route out, and they could not do it. Bad user interfaces on good technology.

If you have been watching this market closely, you would know that it's got nothing to do with a bad user interface; the Edge 305 is a route-recording GPS, not a navigation GPS. I won't argue that it may be overpriced for what you get, but to be fair it's not advertised as a device that will help you find a route when you are off course

I'm a bit of a Luddite as far as GPS goes. We've been using bike computers on our bikes for a long time. The stoker wants (& has) a computer but because ours is a coupled bike, I want a wireless for the rear. This limits us to the Cateye 3000 or a VDO. We are used to (and like) the simple Cateye user interface. We've had the VDO for a while, can't get used to it and have grown to hate it. I was going to get the Cateye 3000 to replace the VDO but found that I could get a Garmin Edge 205 for about $50 more than the Cateye 3000. Base on what some here have said, maybe we would be disappointed replacing a conventional bike computer with a GPS based one. We almost never ride in unfamiliar territory so having a navigation GPS would rarely be needed. Also, once the novelty wore off, I doubt that we would bother downloading the info to a computer.

Mostly, I just want a good wireless computer for the stoker position. It seems like a GPS based unit would solve the transmission distance problem and we wouldn't have to rely on a wheel sensor for speed, distance and average speed.

However, I have read mixed reviews on the Cateye 3000 series (maybe not as dependable as the shorter transmission distance models).

Mostly, I just want a good wireless computer for the stoker position. It seems like a GPS based unit would solve the transmission distance problem and we wouldn't have to rely on a wheel sensor for speed, distance and average speed.

The Garmin Edge 305 has a wireless rear wheel sensor. It's a combined speed/cadence sensor. The GPS doesn't figure instantaneous speed very well; it has to calculate speed based on two GPS coordinates and the time elapsed between them - and that's a function of the sampling rate. The sensor gives you the current speed as well as cadence.

If you have been watching this market closely, you would know that it's got nothing to do with a bad user interface; the Edge 305 is a route-recording GPS, not a navigation GPS. I won't argue that it may be overpriced for what you get, but to be fair it's not advertised as a device that will help you find a route when you are off course

The 305 has a tracking screen/function that you can use to find your way back to where you started. It has come very handy to me when ridding in non-familiar areas by ourselves or with groups of fast ridders that we meet along to ride. We get carried away working on the pace line and when it is time to go back to the truck this feature has saved us time and effort.

The Garmin Edge 305 has a wireless rear wheel sensor. It's a combined speed/cadence sensor. The GPS doesn't figure instantaneous speed very well; it has to calculate speed based on two GPS coordinates and the time elapsed between them - and that's a function of the sampling rate. The sensor gives you the current speed as well as cadence.

Just to be clear, the sensor is optional... Debbie's is installed on her Ritchey road bike which has been relegated to indoor / stationary training duties. If she was interested in cadence monitoring then, yes, it would make sense to use the sensor all the time. However, she seems to be more interested in working to maintain her average speed moreso than the other functions.

As for the GPS speed accuracy, I have Debbie's 305 set for 1 second sampling rate and the speed is very accurate and in sync with the CicloSport HAC4 that I use up front on the tandem.

If you have been watching this market closely, you would know that it's got nothing to do with a bad user interface; the Edge 305 is a route-recording GPS, not a navigation GPS. I won't argue that it may be overpriced for what you get, but to be fair it's not advertised as a device that will help you find a route when you are off course
Yes, I abbreviated my comments a bit too much. I have worked with the 305 users in the following way: I make maps (MapMyRide.com), which they download to the 305, which is then used on a ride for navigation. This kinda sorta works, but every step is bad user interface. That is the background behind my general negativity on the 205/305. It is more than just a recorder (especially if you go by their marketing), but it is far from your typical car GPS. And, it actually was advertised as something that could get you back on course; but the reality is that it can only tell you when you are off the course -- it can't tell you what street your are on, etc.

Now, on yesterday's ride, it was not planned/mapped in advance, so this didn't really apply. I didn't really expect them to navigate me outta there. I can't wait until somebody shows up with a 605/705 -- then I will expect them to be able to help out in a situation like yesterday. But my playing with them in stores indicates that I shouldn't expect too much. The UI is still behind the car systems by a generation -- at a price higher than car systems.

705 - Color, map support, cadence/speed sensor, HR monitor, Wireless Power meter compatible, actual altimeter instead of gps calculated altitude. 15 hour battery time (The whole enchilada)

605 - Color, map support. No wireless sensors, no altimeter. 15 hour battery time

305 - B&W screen however has HR and cadence sensors, but does not support power meters. Also has altimeter. 12 hour battery time.

205 - I think the 205 does not have sensors like the 605 and is in B&W as well. 12 hour battery time.

I went with the 605. I wouldn't mind having the HR but there seems to still be problems with the altimeter software and I don't think that the 705 reports any more of an accurate altitude than a 605 does at least until there is a software patch to fix that.

I have used mine to program in routes for rides in unfamiliar areas. The routes give turn by turn directions so I don't need to bother with paper route slips. One screen acts as a auto scrolling route slip and the Garmin can guide you back to the route if you accidentally miss a turn.

I've not looked into GPS devices to any extent but it sounds like you can get a well featured car type unit for about $350 while you can pay $500 for a relatively stripped down bike mount model.

Would it be practical to try to adapt a car type unit to a bike? I assume one issue would be the power source.

I've not looked into GPS devices to any extent but it sounds like you can get a well featured car type unit for about $350 while you can pay $500 for a relatively stripped down bike mount model.

Would it be practical to try to adapt a car type unit to a bike? I assume one issue would be the power source.
Not just power, but physical size also.

I have 3 Garmin units and use them on various bikes depending on what we are doing. My main road singles a 705. The MTB and SS a 305. The tandem captain 705 and stoker 205. I move the 705 from bike to bike just as with the 305.

I have Speed/Cadence sensors on all that accept them. GPS is not 100% reliable in heavy tree cover or canyons (urban or natural), nor in tunnels. The speed sensor helps maintain the speed reading. GPS based altimeter (205) can be highly inaccurate compared to a barometric altimeter (305/705). HRM is a must for me since having stents put in this March (305/705). My next big gadget is to learn to train with power (705). Also the 705 has eliminated the 4 hour per second recording limit.

If you want good maps Garmin makes a handle bar mount for models hikers like to use. I have been using an E-Trex Legend for 4 years. It is easy to draw routes on my computer and down load to the GPS. We have never been lost. Just follow the on screen arrow or the marker on map view.

My son uses a Garmin Nuvi with a handlebar mount. The stock picture shows it on mountain bike bars but he mounts his on aero bars.

I have 3 Garmin units

You must be a stockholder!

Sounds like the 305 might be the sweet spot.

My son uses a Garmin Nuvi with a handlebar mount. The stock picture shows it on mountain bike bars but he mounts his on aero bars.

An iPhone 3G would be smaller and give him a cell phone at the same time. He could then use Bicycle Gear Calculator to figure out what chainring cog combination to put on his fixie! :lol:

I'm fine with my 305 w/HR, no cadence. I know what my legs are doing, or if I want to confirm I can count RPM for 15 sec.'s and multiply by 4. If I'm spinning too fast, stoker doesn't wait that long to tell me she wants a taller gear.

I plug it into my computer after every ride to download my ride info and recharge it at the same time. It gives me a ride log with total miles, avg. speed and max. speeds and HR's, feet climbed and descended and a lot more without typing in individual data points. Sure, some higher end magnet computes can do the same but we're admitted semi-addicted gadget freaks and it's much cooler when the data comes from outer space. I almost can't wait until my 305 starts to fail so I can go to the color screen 705.

Stoker has an eTrex Legend. It has minimal navigational function standard or can be upgraded with City Map software to store more detailed information a state or two at a time. Almost all of our out of town rides are supported and usually have very good maps and cue sheets. She navigates and is very good at picking up deviations between the cue sheets and distance traveled by GPS. Sometimes a printed route's total mileage gets off by .1, .2 or .3 along the way, she makes a mental note and calculates the deviation for the next turn. Sometimes the cue sheets go up and down a couple of tenths throughout the ride, but I'm not too macho to ask for directions on a regular basis and we rarely make a wrong turn or get off route.

If we were doing long unsupported rides on unfamiliar routes we'd look at a different Garmin unit with more navigational functionality and a larger screen. They've got lots of products available to fit lots of compromises between your wants, needs and budget.

We used to be more active boaters and have used GPS for a number of years, so we are very comfortable with the user interfaces, and also have a very easy to use Garmin Nuvi for the car. In a pinch we could use it's extensive navigational capabilities on the bike but we'd be turning it on and off a lot as it only has about 4 hours running time on its internal battery when it's not plugged into a 12V outlet.

There are a handful of manufacturers that compete well with Garmin in Marine, Auto and Aviation, but for the cycling niche I think they pretty much own the market. No, I don't own any Garmin stock but after reading what I just wrote, I may just look it up and buy some.

No, I don't own any Garmin stock but after reading what I just wrote, I may just look it up and buy some.

Hmmmm. Probably not. We used to own it and it's fair to say they made some poor business decisions in the past that have continued to beat-down on the stock price. They've been poised for a come-back about once a month every since, yet the stock value continues to erode.

The car version lacks some key features that may or may not be a problem. The battery time appeared to be lower on the ones that I looked at, and they did not support any bicycle specific features to aid in training. The $500 version for bike also has heart rate and compatibility with wireless power meters. If you are going to make that sort of comparison you really need to look at the 605 which is at least $100 less than the 705.