GPS for the bike

[NickM]

...it chooses main roads because the software seems to be car based.
i've got both the above and tracklogs mapping for planning and downloading rides to the gps , it's the only way to choose the roads you want as far as i know...

I'm pretty sure that there is an option accessible via the main menu screen to tell it to plan routes avoiding main roads. I don't use mine this way, so I haven't done it.

A tip: the Garmin GPS handbooks are not very good. They are the product's greatest weakness, IMO. But if you download the .pdf version to your desktop, you can use Adobe Reader's search facility to find information in the handbook which (given the lousy index) is otherwise hidden away.

 

[ColinJ]

That's very handy to know - thanks

Stevew, don't give up on your eTrex! As long as it can accomodate 100+ trackpoints at a time (mine seems to hold 124) it's very useful for cycling when used in "compass arrow" mode in conjunction with a track loaded from OS mapping software. Planning a ride on the PC in advance has the great advantage of keeping you away from unpleasantly busy roads and awkward junctions, while still allowing exploration. My yellow eTrex and Tracklogs mapping have been a tremendous aid to cycling pleasure. All the more so since my eyesight is no longer up to reading map detail or a route sheet on a bumpy road.

Yes, NiMH cells that didn't auto-discharge so quickly would be good! I gave up expecting my NiMH batteries to hold a charge for long periods and got into the habit of always charging mine overnight before a ride.

I never quite understood the difference between trackpoints and waypoints, and therefore tracks and routes. I always thought one plotted waypoints to build up a route and that a track was what the GPS stored to show the actual course taken?

I've noticed that the Etrex tracklog of a ride is basically an approximation. The device seems to calculate where it will be at the end of the next sample period based on current speed and bearing and takes the next reading when it thinks it should have got there. My evidence for this is that the part of a tracklog relating to a fast switchbacked descent repeatedly 'overshot' the bends by 50 metres or so, much more than the actual GPS error. The same descent ridden more slowly was tracked correctly.

I didn't like navigating in compass arrow mode having tried it out on foot when I first got my Etrex. I plotted a walk past the local Post Office, then along a canal towpath. I tried to imagine being on the bike in traffic. It was okay when I was some distance away from a turn at some traffic lights but then as I got closer, the arrow started pointing in the wrong direction! If I was on my bike I'd have got in the right hand lane and signalled right whereas I actually wanted to go left. I deduced that the GPS error and perhaps an error in plotting the waypoint had added together to put the 'virtual waypoint' to the right of the actual junction. I followed the arrow which then promptly flipped round to point to the next waypoint which was by then behind me! I persevered and walked down the road past the P.O. and the whole time the arrow was pointing to my left as if telling me that I should be the other side of the building. On foot I could work out that this was due to the inherent error in the GPS reading but I wouldn't like to worry about that in traffic.

After that I switched to using breadcrumb trail mode and found that to very satisfactory. I can tell at a glance when I am approaching a waypoint and where I will be going after that so I can get in the correct lane, adjust my speed, whatever. It is helpful to label the waypoints using the system suggested here so one can see in advance which exit to use at a roundabout for example. It is also necessary when navigating a complex junction where GPS error can lead to doubt as to exactly which road to take. I've only got confused at what the Etrex is telling me when I haven't bothered to label the waypoints. If I was tackling a roundabout, leaving by the 2nd exit, and then turning immediate right, I'd label it xxxE2R where xxx is the waypoint number. The numbering is necessary because the Etrex needs to have a unique label for each waypoint and it isn't wise to let it rename them itself (which it will do if you don't!). What I'm saying is that you can't have 2 or more labels such as L so call the first one something like 023 L and a subsequent one 097 L (whatever). It obviously makes sense to number them in the order they occur on the route. If I am following an audax route I usually copy the labels onto the relevant parts of the routesheet in case I have to refer to it (which I rarely have to now).

One other thing - the Etrex navigation trail can be displayed at different resolutions which can be changed 'on the fly' or set to auto-range. It can be a bit confusing if one isn't sure of the resolution being used because a quick glance at the GPS screen might make one think the next waypoint is closer or further away than it actually is. Riders who have ridden with me when I'm using the GPS know that I call out of most the turns in plenty of time, but a few times I've had the screen resolution wrong and we've missed the turn.

The great thing about navigating by GPS in this way is that it mistakes are obvious in seconds. I'd probably only make four or five 'two second' mistakes in a typical 200 km audax whereas my more experienced audax mates frequently end up on 5 or 10 km detours when they make mistakes interpreting their routesheets. I know which I prefer !

 

[NickM]

Colin, I'm no expert (I've worked out my way of using each Garmin model and just stick with that), and I think that GPS terminology is terribly confusing... but tracks, made up of trackpoints, contain much less information than routes (normally made up of waypoints, although they can also use trackpoints) and therefore require less storage space. My yellow eTrex can accommodate up to 10 tracks, each of 124 trackpoints, but only a single route of 50 waypoints, which I would not have found useful.

The Legend Cx which I use now has much more room on board and seems happier (for the use to which I put it, anyway) working with routes rather than tracks.

I find that careful track creation on the PC is the key to successful use of the "compass arrow" screen for navigation, particularly using the yellow eTrex, on which I found it most effective to put trackpoints just after junctions, so that the direction arrow would begin to swing left or right as I approached the turn.

Using the Legend CX, with its audible there's-a-waypoint-coming-up signal and distance-to-next-waypoint countdown, I prefer to put trackpoints just before turns.

 

[will]

I have used a Garmin Etrex Vista C for a few years on my bike and in my car - WITH THE CORRECT map it will give route directions, you can preload routes, great color screen, etc. Maps are silly expensive in Europe - (bastards)

But fantastic, everything except a HRM/CADENCE (which is why I also own a 305 edge). very handy on vacations - for preplanning routes that you don't know - a very under-rated device.

I live in Europe - if you want one they are about half the price on the USA - EBAY it.

 

[ColinJ]

... My yellow eTrex can accommodate up to 10 tracks, each of 124 trackpoints, but only a single route of 50 waypoints, which I would not have found useful.

Ah, that was the early version of the basic yellow Etrex; I wouldn't have found that useful either. I inadvertently won an eBay auction for one but the vendor was good enough to cancel the sale when I found out it wasn't the latest model. I bought a new model elsewhere and it can store 20 routes of upto 124 waypoints, subject to a maximum over all routes of 500 waypoints. The waypoint data is stored separately and routes are made up of 2-124 of them.

I find that careful track creation on the PC is the key to successful use of the "compass arrow" screen for navigation, particularly using the yellow eTrex, on which I found it most effective to put trackpoints just after junctions, so that the direction arrow would begin to swing left or right as I approached the turn.

I can see that that would help.

Using the Legend CX, with its audible there's-a-waypoint-coming-up signal and distance-to-next-waypoint countdown, I prefer to put trackpoints just before turns.

As I mentioned above - the lack of an audible warning is a nuisance on the basic Etrex. It does flash a message on the screen just before a waypoint is reached, but if you are looking at the screen you probably know that anyway! If you are not, you don't see the message...

I think the problem with not putting waypoints/trackpoints exactly where they should be is if you ever want to do the route in reverse. That's something I do from time to time. I have favourite rides that I nearly always do in a particular direction but eventually it becomes boring doing that. It's amazing how different a route can seem when doing it in the opposite direction. Mind you - I know those routes off by heart anyway.

 

[ColinJ]

I have used a Garmin Etrex Vista C for a few years on my bike and in my car - WITH THE CORRECT map it will give route directions, you can preload routes, great color screen, etc. Maps are silly expensive in Europe - (bastards)

But fantastic, everything except a HRM/CADENCE (which is why I also own a 305 edge). very handy on vacations - for preplanning routes that you don't know - a very under-rated device.

I looked at the Edge, but I didn't like the 12 hour battery life coupled with a non-removable battery. It would be fine most of the time but I have done 14 hour rides before now, and I might build up to about 20 hours eventually. I couldn't afford to have 2 devices so I needed one with a decent battery life.

 

[NickM]

I think the problem with not putting waypoints/trackpoints exactly where they should be is if you ever want to do the route in reverse...

True enough. I plan most routes to be anti-clockwise, since this reduces the number of right turns. (I also try always to turn right onto, and left off, main roads).

I agree that a route done in the reverse direction is nearly as novel as an altogether new one. If I want to do a route in reverse, I make a second, clockwise, version of the Tracklogs file, simultaneously reviewing it to try to avoid right turns off main roads.

 

[davidwalton]

I am getting the impression that GPS systems talked about here are not the same as SatNav that cars use?

All I need is a waterproof SatNav that works like a car one does, allowing me to choose road types, so as to avoid major highways, and have a battery that gets me there and back, possible the next day.

Voice commands shouting turn left/right/straight on, being loads better than following a small screen, so a speaker is needed.

as for finding routes, want to be able to enter post code, partial address for to and from, etc..Facility to change route if I want, or go off route and the system work out new route from current location.

Don't need system that covers anything other than roads, plus places of interest. ie. hotels, stations, etc, etc.

 

[ccj]

That's very handy to know - thanks

You're welcome.
The cheapest place so far:

http://www.component-shop.co.uk/html/instant.html

but if you find cheaper, perhaps you'd let us know?

Voice commands shouting turn left/right/straight on, being loads better than following a small screen, so a speaker is needed.

AFAIK all such units have a speaker, but unless you travel on D roads, & or have incredibly good hearing, the speaker audio will be useless on a bicycle. One could of course use an earphone.

as for finding routes, want to be able to enter post code, partial address for to and from, etc..Facility to change route if I want, or go off route and the system work out new route from current location.

A dedicated Satnav, or a PD(N)A will do just that.

I agree that a route done in the reverse direction is nearly as novel as an altogether new one.

Memory Map s/w will make a reverse route by right clicking your route, & select "reverse route".

 

[ColinJ]

Memory Map s/w will make a reverse route by right clicking your route, & select "reverse route".

Yes - I use that feature frequently, sometimes in an unusual way... If I want to drastically change the start of a route, I do the following:

Reverse the route
Click on what was previously the first waypoint, but is now the last
Select Add waypoint after
Repeatedly use the Backspace key to remove unwanted waypoints
Add new waypoints to what will become the new start point
Reverse the route again

The point I was making was that if using compass arrow mode only works properly when waypoints are placed after junctions, reversed routes won't work properly unless every waypoint so placed is moved to the other side of its junction which would be a bit of a pain to do for a long route.

 

[ccj]

If I want to drastically change the start of a route, I do the following:

Reverse the route
Click on what was previously the first waypoint, but is now the last
Select Add waypoint after
Repeatedly use the Backspace key to remove unwanted waypoints
Add new waypoints to what will become the new start point
Reverse the route again

The point I was making was that if using compass arrow mode only works properly when waypoints are placed after junctions, reversed routes won't work properly unless every waypoint so placed is moved to the other side of its junction which would be a bit of a pain to do for a long route.

I'll try that technique, thanks.

I don't have any experience of a Garmin unit, but reading both posts, I think I see what you mean now.

I've just discovered that using the European version of MM, a scanned-in (TIFF) map can be imported, so I may experiment with that too.

 

[ccj]

Anyone seen this?-

http://www.decathlon.co.uk/EN/files/assets/27602610-sitegetinshape/sitegetinshape/index.html

It looks very much like the cheaper Garmin bike GPS, but at a very good price.

Thanks Mr. Paul - looks worthy of further investigation:

http://www.geonaute.com/EN/keymaze-300-19389541/

 

[ColinJ]

Anyone seen this?-

http://www.decathlon.co.uk/EN/files/assets/27602610-sitegetinshape/sitegetinshape/index.html

(click on sports accessories and Geonaute)

It looks very much like the cheaper Garmin bike GPS, but at a very good price.

It says on the Geonaute website that it is not possible to upload preplanned routes to it from mapping software - that's a bit of a restriction. It also has a pretty limited waypoint memory and a maximum of 15 hours battery life. The killer for me is - "You can use the arrow to locate your position in relation to the North. But the Keymaze is not intended to be used for navigation, but simply to assist you." That is, it tells you where you went rather than how to get there. It would be okay for exploring and then replaying your route but that would be about it.