If you look very closely at the above photo, you can see a cable sticking out of the bottom of my saddle. A few months ago, I hired a bike with a dropper post and although the snow meant that the only trails I could go on didn't really benefit from a post and although I kept dropping the seat post instead of changing gear, I got an idea of how useful it could be. And then, a couple of weeks ago, I went cycling in the Eifel. There were enormous storms, with some of the paths turning into small rivers with much erosion, so that I spent a lot of time going slowly and carefully down the steeper hills. Neither hanging over the back of the saddle nor stopping to put it down and then up again every few minutes are ideal solutions for that situation. However, when I got back and started searching for possibilities, it was clear that there was a bit of a problem. The bike industry is rubbish when it comes to defining standards and sticking to them and one of the things that varies unnecessarily between manufacturers is the diameter of the saddle post.  Apparently, my three-year-old bike has an 'old fashioned' diameter and it turns out that most dropper post manufacturers don't make posts in its size.  My LBC also tried really hard to find something for me but without success, unless I was willing to pay a ridiculous price for the most expensive ones in existance. However, just when I was about to give up, I found an English shop that did have one that fitted, with good reviews and the right price. And what is more, I did not even have to indulge in dubious import practices with the help of English relatives, but they shipped to the Netherlands for me.

And so it was that yesterday I headed for the Posbank, a trail with some reasonable hills (but nothing really dramatic) and my new dropper post attached. Would it really be useful round here, or only with the 20-30% slopes of the Eifel? Indeed it was! On slopes of 10-15% with slippery loose sand, I could definitely go faster, more confidently and quite likely even safer down them, with my centre of gravity moved downwards, and I could hang just above the saddle without being so far up in the air that I felt like I was hovering over the handlebars. On the way back I also found an unexpected benefit.  There is a tunnel under the railway line, I think originally built for animals to get through, but now also in use by mountain bikers. I am always a little nervous of it as it is just a little lower than my head height, but if I bend my head down then my helmet obstructs my vision. Lowering the saddle a few centimetres turn out to be very handy in that situation too. 

Polar GPS cycling computers are not so well known as Garmin or other makes like Mio or Wahoo. Polar is best known for its heart rate monitors and indeed that is how I came across the V650.  My 10-year-old Garmin 60C was still working fine and is indestructibly built, but I had two problems with it.  One is that its old screen technology means that it is harder to see for those of us needing reading glasses than a modern one. The second is that I wanted to measure heart rate, and it could not. A top-model Garmin with heart rate monitor costs in excess of €550 so I started to look around to see what else was available. There are various options, but one that caught my eye was a V650 from Polar, which is a little over €200 including the heart rate monitor and in the end I went for that.  That was about a half year ago, so I've had some time to find out its good and bad points. 

Summary

Excellent value for money, but sometimes a bit inconvenient to use.

Heart rate monitoring

In the past few years, many smartwatches have come onto the market which measures heart rate using an optical sensor at the wrist. Last year I was part of a project with the University of Twente in which we validated those and in short, their data is not good. The wrist is an inherently poor place to put such a sensor and although on a road bike this might not be a big problem as the wrist stays quite still, bouncing around off road is going to give rubbish data. I don't know how good the optical sensors are which attach to the upper arm (I imagine they are not comfortable, though that is a guess), but when it comes to it, short of attaching ECG electrodes to yourself, the only option is to use a chest-strap. The one from Polar works perfectly; you can read the data from the V650 or a smartphone and with the latter, it is accurate enough to calculate heart rate variability, should you be interested in that (e.g. with Elite HRV). The battery level of the chest strap can be read in the Polar app, though oddly neither the V650 nor the app warns you when it gets low. It took about 5 months for me.

Polar flow

The heart rate data has various uses, but one very nice aspect of Polar's implementation is its calculation of your recovery status. Sof if you look at the graph below, you see that on Thursday 10th, I still had a considerable load from my trip the previous Sunday (the top two dotted lines are for ('strained' and 'very strained') and that it was not sensible to attempt an even longer ride. But it was Ascension Day (a holiday), so I went anyway and indeed was struggling by the end.  You see that clearly in the Polar Flow website (strangely, not in the Polar Flow app), where you can also see various other collected data about your cycling.  One thing that is a little frustrating is that there is a menu item on the Polar FLow site 'Programs' where you can make a training program, but that is entirely aimed at runners, not cyclists. You can connect your account to Strava, so that the data is automatically linked and also upload Strave Live segments (but that doesn't interest me).

GPS mapping

Another somewhat bizarre design decision from Polar is that when you want to follow a route on the map, you can only upload the tracks to your V650 by using the website.  To select the map area, you have to drag a square over a map of Europe on the V650. Then to upload a GPX file to your V650 you have to go to Polar Flow website, find the little star which means favourites, then upload the GPX (multiple times if the GPX contains multiple tracks, stupidly) and finally sync your V650 to get the maps and tracks.  I don't mind the maps so much, but I am waiting for the moment when I want to go mountain biking and don't have an internet connection to upload the tracks before I set off.

The maps are from Open Street Map and are excellent. The only concern I have is that sooner or later Polar will stop supporting this device and then I cannot update my maps any more.  On the other hand, they are still providing both maps and software updates years after the release, so that is good. An excellent feature of my old Garmin was that you could easily download maps yourself (see my Links page). Your current location is shown as a red circle, the route you have been as a blue line and the downloaded route as a red line. Several times the red blob has disappeared on my device, and I have had to restart it. Not what you want in the middle of a ride. A much bigger problem is that you cannot change the colour (or width) of the red line. Like 8% of men, I'm red-green colour blind and although most of the time it is not a problem, sometimes I really cannot see the difference between red lines on the map and other lines (paths and so on). If I had one tip for the next software upgrade, it would be to let me do this. [Note, this seems to be improved with the 2019 map update]. The other serious omission is that you cannot show waypoints (points of interest, POI). Last week I was following the official routes on the Heuvelrug, and there is one point where I wanted to cut over from the Leersum track to the Amerongen track. Unfortunately, Polar make marking points like that impossible. Bizarre seeing that is such a standard function in every GPS device.

There is also a mode where you can follow tracks with turn-by-turn instructions, rather than just the line.  I am told that works well on the road. However, I've stopped using it off-road, as it is a bit hopeless. Often the starting point of the track is not where you start your ride. This seems to confuse it and I did not find any function to take me to the start. Then, if the GPS signal is not brilliant, it often thinks you are not on the track, so loses the routes. And very irritatingly, if your track is composed of several segments, each is a separate track, so you have to record separate tracks, which messes up your stats.  It is a shame it doesn't work better, because when it does know that it is on the track, there is a nice wide line, which does look different from other lines on the map.

Hardware and software

The V650 is well-built and seems to be very waterproof. A very nice feature is that it has an emergency white LED light built into the front, which you can set to go on automatically when it gets dark.  The screen is very clear in all lighting conditions. The only time I've had a problem was in the snow when the bring light from the snow darkened my glasses but the backlight did not turn on and it was cloudy so the direct light from above didn't illuminate the screen. I suspect that I could have fixed that by fiddling with the settings. The Bluetooth connects easily with the heart rate monitor, but I didn't succede in getting it to connect to my phone. In fact, I tried three different makes and with all three the pairing failed. On Polar's website, it says they only support a very limited range of phone makes.  Many modern GPS bike computers show phone notifications, which strikes me as useful, to save stopping and getting your phone out of your rucksack to see if it was anything important, but should Polar ever introduce that feature it will be useless for me seeing the Bluetooth connection doesn't work. Another feature that Garmin has and Polar doesn't is to use the GPS of the device to send your location to someone at home via your phone. However, apps like ViewRanger can also do this (not google's location sharing, that is often inaccurate) and I don't know how much the saving in phone battery from not using its GPS is counteracted by the drain on the battery from the Bluetooth.

The battery life is excellent, easily lasting all day.  The only time the battery has run out is in the shed. That is because of a bit a stupid design fault; the on/off button is precisely where you put your thumb when inserting the device into its holder on the handlebar.  So it is easy to accidentally turn it on, and if you don't notice for a couple of days, then it will be empty. That has happened twice to me now. Fortunately, it charges quickly. 

A nice feature is that the interface is very customizable; there is a very wide variety of data fields to choose from and lots of ways to display them. A recent software upgrade added a new one; incline. That used to be only available with a speed sensor on the bike as GPS is not accurate enough, but someone at Polar had the bright idea that using a running average of 100 samples or so (or at least that's what it looks like - this is an undocumented feature), means that the inaccuracies will be averaged out. That does mean that it only makes sense on a long hill with a fairly constant gradient, but that's still nice to have. It is nice that you can customize it to show two map pages, one for the whole route, the other zoomed in. Just a pity that it doesn't remember the zoom factor, so you have to do that every time.

Conclusion

On the whole this is a super device, with lots of plus points and a very good price, but it is a shame that it is let down by a few poor design points and bugs.

Apparently, Face-Twits are more likely to click on a blog with  numbered lists for some unknown reason, so in honour of them, here is a list of differences between when I cycled the Montferland route (twice) two weeks and one day ago, and today.

1. Temperature
A couple of weeks ago, I made a mistake.  Because it had been quite nice the day before, I foolishly put on summer gloves. It was so cold! Not just the actual temperature, but the wind and rain meant that my hands were so cold that towards the end, I actually had difficulty changing gear as my thumbs wouldn't respond. In contrast, today it was 30 degrees, according to the thermometer in the car, which even if it was exaggerating, means that it was ridiculously hot for April.

2. Wind
There had been a storm the night before, even bringing down a large tree that some foresters were busy clearing as I went past. That also meant that there was quite a lot of wind whilst I cycled. According to the interesting website https://mywindsock.com, all that wind was equivalent to 9 km extra cycling.  I doubt if that website knows how much of the route was sheltered inside the woods, but nevertheless, it was quite a fight at times.  By contrast, today the air was hardly moving.

3. Water
Not content with bringing the wrong gloves, I also made a much more serious mistake two weeks ago.  I did not take enough water.  That meant that it ran out about 3/4 the way along, and in turn that meant that shortly after that the hills all felt twice as steep and I was unbelievably exhausted at the end.  Today I made sure my rucksack's bladder was full to the brim and that I had an extra bottle as well. That made a huge difference, not only did I finish half an hour earlier (though the lack of wind may have helped there), but I still had some energy over at the end.

4. Spring.

[text continues after photo]

It is amazing what a difference just two weeks can make at this time of the year. Leaves everywhere. Birds in full song everywhere (and either lots of Green Woodpeckers or one that curiously followed me along the whole way). Butterflies everwhere (lots of Clouded Yellow).

5. Dust
It is amazing what a difference just two weeks can make. All the muddy goo has magically turned into dust. Some parts have had gravel added (apparently they not only remove fallen trees for the annual fee for using the trails). The dust does make it quite tricky in parts though, seeing how as dust is not the least slippery substance around. There are also several downhill stretches which have deep ruts running across them, meaning that the bike bounces up and down quite alarmingly, even to the extent of shaking my GPS loose at one stage, and then at the bottom of the downhill stretch, a big pile of dust.

6. Tyres
One other factor in addition to everything above which might help explain why I did it in half an hour faster this time was that I had changed my back tyre from a winter Nobby Nick to a summer Racing Ralph. It really does seem to make a difference.

7 - 10. Still thinking of those points. Here is a pretty photo instead (Stitchwort).