Australian Cycling Forums - Bicycles Network Australia

Hi Guys and Gals,

I know some of you also own a Polar CS200 bike computer so I thought I'd check to see if anyone else has experienced this problem.

I have two road bikes, one for commuting and one for training/weekend rides. On the training bike (CF) I have both speed and cadence sensors and always wear the HRM sensor, and all works fine.

On the commuting bike (Aluminium) I only have a speed sensor and rarely wear the HRM sensor. What occurs on a regular basis is this...when I pull up at a set of lights the speed indicator doesn't drop to zero and after about 5 seconds the distance indicator starts to climb at around 0.1km every couple of seconds. So after a 30 second stop I've magically added 1.5km to my trip and my average speed makes me look like an A grade rider (which I'm not by a long stretch). Once I get moving again the speed indicator begins to work again but of course my trip distance and average speed is now totally bogus.

Based on the fact that the computer works fine on the other bike (and the speed sensor on that bike is only a couple of months old) I suspect that the battery in the speed sensor is dying. Considering that a new speed sensor is around $90 (since it's a sealed unit and the battery can't be replaced), and all that I'm really interested in is speed/distance/avg speed I think I'll just get a basic wired Cateye (or similar) computer for about a third the price.

Anyone else experienced a similar problem with the Polar CS200?

Where have you mounted the speed sensor on the ally bike vs the computer? The ally frame and the carbon frame for that matter, both mess with the signals (according to the service bloke) and you need a dead clear line of sight. I had a lot of trouble with the cadence unit and found that the maximum distance stated is just that, an utter maximum (and I'm on steel which has the least affect on the signals). Try moving the computer on the bars, even to the other bar - note, the book recommends that the computer be on the opposide side of the bike to the speed sensor.

You can take your sensor to the distributor to get checked. I did this with my cadence sensor and that's when I started to learn about the frame and positioning. There was nothing wrong with my sensor, it was just the way things were laid out on the bike.

If your sensor is less than two years old, they will replace it free because it's still under warantee.

Finally, you can change the batteries - it just means prising it apart and being careful with the rubber seals and gluing it back together ... but the technician didn't tell me that

Richard

On both bikes I have the speed sensor mounted on the left side of the fork and the computer is mounted on the stem. I prefer to have nothing mounted on the handlebar (if possible). I did noticed the bit in the manual about mounting the sensor and computer on opposite sides, but this doesn't really apply when you mount the computer dead centre (and maybe this is my problem...I will try moving it to the bar on the opposite side).

I've never had a problem with the cadence sensor (which started out on the ally bike and was then moved to the cf). And honestly I've spent the last couple of years working on improving cadence to the point where I hardly need to check it anymore (although it's still interesting to watch it drop to 50 or below on monster climbs in my lowest gear when I'd normally be spinning in the 95-100 range).

Thanks for the tip about the battery. If moving the unit doesn't work this will be Plan B. I still suspect that the battery may be the problem since I had no problems when it was new. Wait a minute...I also had the computer mounted on the bar when it was new .

Me thinks I need to experiment a bit .

David

I recall a thread on another forum about 12 months back, with people reporting just your problem. Everyone of them had the computer mounted on the stem, though no credible reason was ever put forward for why this might be so ... apart from electronic bastardry

Richard

Thanks Richard. I will definitely move the unit to the bar and see how we go. Won't be riding the ally bike again until next week probably. The rest of the week's rides involve hill climbing and the CF bike is better suited (it has lower gearing).

Unless it's raining of course...the ally bike cops all of the crap weather .

How do you get on swapping the computer from one bike to another? Does it have some sort of auto detect? Do you have to tell it? Or don't you bother? I run two bikes with different wheels but would like to use the computer on both.

Richard

I have never noticed that but while on the subject of CS200...quite often at the start of a ride my heart rate (on the monitor) will be up around the 190-220 mark)it takes about 5 minutes for it to start reading my proper rate.Dosen't happen all the time but quite often

toolonglegs wrote:I have never noticed that but while on the subject of CS200...quite often at the start of a ride my heart rate (on the monitor) will be up around the 190-220 mark)it takes about 5 minutes for it to start reading my proper rate.Dosen't happen all the time but quite often

Well, start your ride out the front of the old duck's house, not the house of the twenty year old lass with the filmy curtains

Being serious, is the strap properly wetted? Back in the days when I was a bit careless there, I used to get high readings like that (scares the willies out of you). Now I make sure the pads are soaked.

Richard

Well two pretty young things did shout out "mmm love a man in lycra" at the start of my ride...but don't think my heart would go that high
Yeah wetting it lots dosen't seem to make much difference...although it does have a habit of looking like I am tweaking my nipples ...which brings on another problem I sometimes get...chaffed nipples!...now that can put you off riding!!!

Chaffed nipples...nope, can't say that has ever been a problem with the CS200. Thanks for the mental image though.

Richard, to answer your question: both of my road bikes have the same wheel size and I'm not that worried about keeping a record of how far each bike has travelled individually so as far as the computer is concerned both are Bike 1. I only have one cadence sensor though so I manually turn off cadence on one bike (if I remember). Doesn't matter really...either the cadence reading is blank if you turn it off or it just reads zero if I forget.

The only problem I have swapping the CS200 from bike to bike is the tendency to drop it occassionally...and usually on concrete .

europa wrote:

toolonglegs wrote:I have never noticed that but while on the subject of CS200...quite often at the start of a ride my heart rate (on the monitor) will be up around the 190-220 mark)it takes about 5 minutes for it to start reading my proper rate.Dosen't happen all the time but quite often

Well, start your ride out the front of the old duck's house, not the house of the twenty year old lass with the filmy curtains

Being serious, is the strap properly wetted? Back in the days when I was a bit careless there, I used to get high readings like that (scares the willies out of you). Now I make sure the pads are soaked.

Richard

I have this problem with the HRM strap for my Garmin. Fitted new battery, soaked the bugger in water before and during my rides, but nothing seemed to help. Like TooLong wrote, it seems to settle down after 5 minutes or so, but on todays ride it was registering my HR at 235 even after 30 minutes in the saddle. I was damn close to un clipping it and giving it the old heave-ho into the scrub.

Might make a trip to a Garmin distributor for some advice.

Hey TooLong, does your HR increase as your speed increases? This is what happens with me.

Kev.

No,it just seems to stay high for up to ten minutes then comes right,speed dosen't make difference...bit of a pain but I can live with it.

I get spurious HR indications if the HR sensor pads are dry.

At the start of this thread I mentioned that the Polar CS200 works perfectly on the CF bike. Well that changed this morning.

On Thursday mornings I do a regular long ride to work that is approx 61km. At one set of lights I closely watched the CS200 and observed the following:

Speed: Did not drop to zero but stayed constant at 22.4km/h
Distance: Did nothing for a few seconds then added 0.9km in about 10sec (This means that for those 10secs I was travelling at 324km/h...and boy it really took it out of me )

On a long ride this doesn't have a huge impact on the stats. At the end of the ride the Polar said I had done 61.9km at an average of 28.2km/h. If you subtract the 0.9km and use the same recorded time of 2:11:31 the average changes to 27.8km/h. No big deal.

On a short 12.5km ride home which is usually ridden at an average of 29-31km/h the impact can be huge. At times I've had the Polar tell me that it was 17.5km and the average speed was 38km/h.

Anyway, Plan A is to shift things around and see if it helps. The cadence sensor has to stay put, the computer will be moved from the stem to the left side of the bar (same side as the cadence sensor), and the speed sensor will be moved the right side of the forks (opposite to the computer as recommended in the manual). I think I might also bung a new battery into the computer for good measure.

If it wasn't for the HRM component, which has always worked flawlessly, I'd be seriously considering going back to a wired computer.

My wireless computer has these weird readings when the battery voltage starts to get too low. A new battery always sorts the problems out, so far. Maybe it's a consideration on the Polar too.

And considering the battery in the HR sensor had to be recently replaced it's a good bet that the one in the computer is getting low too. Will pick up a new battery today.

lol i just got a Cs2000cad today, look what ive got to look forward to, lol

stevos wrote:lol i just got a Cs2000cad today, look what ive got to look forward to, lol

They are a very good and very reliable unit mate. Yes, we're fighting through some problems, but there'll be solutions. My cadence meter drove me made until I finally admitted defeat and set it up exactly like the books says ... rather than the way the bike shop bloke had done it

Richard

Put a new battery in the computer today and my 12.5km ride home was 16.5km according to the Polar

I've now shifted the mount point from the stem to the handlebar (on both bikes) and will see how we go.

stevos - when it works it really is a good unit. when...it...works

DavidH wrote:stevos - when it works it really is a good unit. when...it...works

Now you're just being fussy

I feel your frustration though. After 1,500km of trouble free running, the cadence on mind went stupid and the process to get it working again drove me to distraction. In my case, it was raising the bars - I'd been working right at its limits and pushed beyond them. Positioning is everything unfortunately. But you're right, when they behave they are a darned good unit - I still remember the eight hours I spent in pouring rain watching the TdU where it didn't miss a beat.

Richard

DavidH wrote:Put a new battery in the computer today and my 12.5km ride home was 16.5km according to the Polar

Did you check all the settings after your battery replacement?

for what its is worth - once I found the ideal position for the sensors and unit my CS200 has worked flawlessly.

Did you check all the settings after your battery replacement?

Sure did. While it's a little frustrating it's not the end of world. At the end of the day I'm still out there riding the bike. Not quite sure how far or how quick, but I'm still out there

I agree..put your speed sensor as far up the fork leg/on the front as possible.You have got the wheel diameter set right....or is it still going when you are sitting still?...weird!.

Maybe he had too much to drink at lunchtime and got lost on the way home

Richard