Garmin Forerunner 305

I’ve had my Forerunner 305 for several years now, so time for a review.

I started doing triathlons a few years ago and bought into the idea of a HRM to record my efforts. Much research led me to decide a GPS/HRM was an essential purchase and the 305 was the most reasonably priced one out there. It’s designed to be worn as a watch and has multiple modes for cycling and running. You can even setup modes for transitions.

Setup was remarkably easy if I recall, it pairs itself with a Garmin HR strap and then just works. It’s waterproof, although not for swimming, quite rugged and although at first it appears to be on the bulky side, it’s fine when worn as a watch. I’ve since bought a couple of quick release kits that give a velcro strap with mount plus a mount and zip ties to go on the bars of the bike. These work really well and allow you to have the device on the bars to it’s easier to see than wearing on your wrist. It’s very secure on the bike and hasn’t come lose of fallen off.  A more recent purchase is the cadence accessory. Yet again this was very easy to fit and just worked.

Key Features

It’s a GPS device so it will show you where you are, with limitations. The screen is a small greyscale lcd and doesn’t show maps. It shows a trace of where you’ve been and it has been very useful when doing a circular route as you can tell the general direction to get back to where you started. if you’re following a route then it shows you where on the route you are.

It can take a while to lock onto the satelites so I now have the habit of turning it on and leaving it on the car bonnet in the drive while i get the bike out of the garage. It can take a few minutes to get a lock in the area you last turned it off and slightly longer if it’s been off and you’ve moved it a significant distance. Overall it’s not a problem. In use it loses reception in tunnels as you’d expect but it’s always been fine in trees when riding in the forrests in Wales.


The 305 talks to a Garmin HRM worm around the chest. It needs to be moist to get a good contact with the skin or you’ll get odd readings. I usually don’t bother as a warm up will provide enough moisture to get a decent contact. It just works and I’m still on my original HRM battery many years of using it 2 or 3 times a week for an our or 2 each time.


The device allows the display of a large range of data – it’s quite impressive and comprehensive and you can cycle over 3 screens worth of displays that are all configurable.

There are 2 general screens and one specific to the type of use (running, cycling, other) and each one is configurable to have between 1 and 4 data items on it. 

As I’m mainly cycling, my current preference is to have the first screen show 3 items with Speed as the largest at the top with HR and cadence below. Second screen shows current time, elapsed time, distance and av speed. The third screen shows gradient, and all the averages.


You can set up your HR training zones if that’s of interest but I’ve never bothered but I do often follow an existing route when riding on my own. In this mode you can follow your virtual self on the ride you originally did and can see if you’re ahead or behind yourself. I’ve used in when doing a route for the first time when someone else is leading as you can toggle to showing a screen that directs you with a large arrow. This is OK if you keep an eye on the route but it’s too easy to ride past a junction and later find the arrow pointing backwards.


This is a cracking piece of equipment and I wear it on pretty much every time I do exercise. Battery life is many hours and I’ve onky every had an issue when doing Mountain Mayhem (a 24hr MTB race) where I’ve failed to turn it off between laps as it died after 15/20hrs or so. It charges via mini-usb so plugging it into a car is easy.

Downloading to a PC is simple and I’ve used sporttracks and Strava as well as the Garmin  software. I’ve ended up using it to record all my rides with occasional route following when I’ve returned to an area after being guided. Fantastic vlaue for money when I bought it but it’s now end of life and has been replaced by the 310XT I believe.






Leave a Reply

Your email address will not be published. Required fields are marked *