Polar CS100 problems

I get that problem rarely, but it happens. It seems to solve itself alone. Give the unit some time before using the guarantee, you do have a guarantee ?

Well I got it from Wiggle so yeah, so long as I don't go over the 30 days from purchase. It's annoying because the thing obviously works, but only when it chooses to. Btw twice now it has gone up to the figure 202 bpm before stopping, which is also kind of weird.

Thanks,

Charlie

try different training routes, you get sometimes interferences from electrical sources on the road. Remember to rinse with water your chest transmitter before and after each ride. Get the battery out to reset everything. If nothing works Polar will have to replace the unit.

Polar's customer service is really good, if whoever you brought it off can't help you, give them a call.

I've got one, and while I do think it's [censored] in other ways, 🙂 I reckon the heart rate bit works as good as my other Polars

Another thing thats bugging me is that my old cateye speedo gives a higher speed count than my Polar, and a friend who has also got both an old cateye and a polar is experiencing the same thing. Its a fairly big gap of up to 1 mph difference between the two cycle computers. I'm using mph rather than kph, and wondered whether it could be something to do with the Polar Kilometres to Miles conversion, seen as the Polar manual says things like "5kmph or 3 mph" which isn't a very exact conversion at all. Could this be the reason......will I be forced to use kilometres instead of miles?

Thanks guys

Charlie

Chazzz801 said:

Another thing thats bugging me is that my old cateye speedo gives a higher speed count than my Polar, and a friend who has also got both an old cateye and a polar is experiencing the same thing.

Don't get me started on THAT!! 😄 If you're keen on accurately recording your speed and distance, I suggest giving up on the CS100!

I spent a whole week of riding trying to get my Polar 725x registering the same speed and distance as my old Cateye Tomo, but I kinda gave up. Then I spent another week of riding (constantly stopping) doing the same with my CS100, only to realize that (I'm pretty sure) it doesn't register speed or distance under about 10km/h!!!! So, too bad if you do a 30km climb at 8kmn/h, coz you'll be ripped off.

Another problem I had with the CS100 is that i got stuck in heavy-ish rain one day, and the screen went totally blank!!! I took the unit off the mounting bracket, shook off some water, then put it in my pocket, and after about 10 ten minutes it came back to life. So, too bad if you need a HR monitor during a wet race! 😄

I now have it on my "dry day only/steel is real/Sunday poser bike", and only use is as a HR monitor.

I have three CS 100 units and have had good service from all of them. Have had no problems at all with the HR function. The speed difference issue probably comes from needing to set the wheel circumference correctly in the computer unit. (Do not assume that all 700x23 wheel/tire combos are the same circumference.) I have noticed that the CS 100 seems to be more sensitive than most computers to having the wheel magnet exactly in the right place relative to the pickup unit.

billydonn said:

I have three CS 100 units and have had good service from all of them. Have had no problems at all with the HR function. The speed difference issue probably comes from needing to set the wheel circumference correctly in the computer unit. (Do not assume that all 700x23 wheel/tire combos are the same circumference.) I have noticed that the CS 100 seems to be more sensitive than most computers to having the wheel magnet exactly in the right place relative to the pickup unit.

What figure have you used for 700x23? The figure the manual gives is 2090, however this website, Sheldon Brown's Cyclecomputer Calibration Chart, suggests 2097, but thats still a slower figure than what my beloved cateye gave.

I have thought of a good idea to solve the problem: Go to a 10 mile TT, and see what distance the Polar says by the end. From that, you should be able to work out a prety accurate figure for wheel circumfrance given the distance you have travelled. The only downside might be the accuracy of the 10 mile TT, and how close to 10 miles it is. Failing that I may just by another cateye.

Btw at least the heart rate seems to be working fine now, so at least its not total dispair🙂

Thanks,

Charlie

531Aussie said:

Don't get me started on THAT!! 😄 If you're keen on accurately recording your speed and distance, I suggest giving up on the CS100!

I spent a whole week of riding trying to get my Polar 725x registering the same speed and distance as my old Cateye Tomo, but I kinda gave up. Then I spent another week of riding (constantly stopping) doing the same with my CS100, only to realize that (I'm pretty sure) it doesn't register speed or distance under about 10km/h!!!! So, too bad if you do a 30km climb at 8kmn/h, coz you'll be ripped off.

Another problem I had with the CS100 is that i got stuck in heavy-ish rain one day, and the screen went totally blank!!! I took the unit off the mounting bracket, shook off some water, then put it in my pocket, and after about 10 ten minutes it came back to life. So, too bad if you need a HR monitor during a wet race! 😄

I now have it on my "dry day only/steel is real/Sunday poser bike", and only use is as a HR monitor.

Lol. It made me wonder whether the cateye was over-estimating my speed, or the polar was under-estimating it. Or whether both were wrong 😕. It's so annoying to upgrade to a bike worth 5x as much as your old bike, and be told your averaging a slower speed than you were on your old bike!

I may just get another cateye for the feel good factor😄

Cheers

calories burned also vary a lot from one unit and/or brand to another

Chazzz801 said:

What figure have you used for 700x23? The figure the manual gives is 2090, however this website, Sheldon Brown's Cyclecomputer Calibration Chart, suggests 2097, but thats still a slower figure than what my beloved cateye gave.

I have thought of a good idea to solve the problem: Go to a 10 mile TT, and see what distance the Polar says by the end. From that, you should be able to work out a prety accurate figure for wheel circumfrance given the distance you have travelled. The only downside might be the accuracy of the 10 mile TT, and how close to 10 miles it is. Failing that I may just by another cateye.

Btw at least the heart rate seems to be working fine now, so at least its not total dispair🙂

Thanks,

Charlie

The exact number really depends on the brand of tire. I think 2090 or 2097 is almost certainly too small in most cases and will underestimate your speed. The box on my Coninental tires gives the number 2122 for their 700x23 but using the rollout test I am using 2115. The rollout test is easy to do and the only real way to go IMO.

http://www.sheldonbrown.com/cyclecomputer-calibration.html#rollout

I do not think you have to do the rollout test with the rider on the bike, by the way. I suspect both of your different computers are off by a little.

billydonn said:

I do not think you have to do the rollout test with the rider on the bike, by the way. I suspect both of your different computers are off by a little.

Without the rider on the bike, the rollout can be off by 4-5 mm or more......or less, depending on the pressure to which you inflate your tires.

Chazzz801 said:

Lol. It made me wonder whether the cateye was over-estimating my speed, or the polar was under-estimating it. Or whether both were wrong

Ha! Yep, it took me a while to realize that, compared to my Catye Tomo, the CS100 was reading lower distances and average speeds due to it not registering speeds under about 10km/h, so it was obviously missing distance each time I slowed and accelerated in traffic

Actually, I might hook it up again today to make sure I'm not lying about this 😄

I gave up and went to the local 2nd hand store and found 4 more Cateye 'model 'G' wiring kits in the "used speedo bits" box. I now have about a dozen wiring kits, so I use the same Cateye head on all my bikes.

531Aussie said:

Ha! Yep, it took me a while to realize that, compared to my Catye Tomo, the CS100 was reading lower distances and average speeds due to it not registering speeds under about 10km/h, so it was obviously missing distance each time I slowed and accelerated in traffic

Actually, I might hook it up again today to make sure I'm not lying about this 😄

.....

I have ridden lots of miles on the CS100 and have never noticed this. There are lots of places on my rides where I have to slow and accelerate so I will pay special attention to that issue today on my ride.

The Polar does seem to be a little fussy about the magnet's location relative to the pickup unit and I HAVE had the CS100 go in to pause mode at high downhill speeds occasionally. (Now that will mess up your average speed calculations for sure!) But I have been able to stop that from happening by adjusting the magnet's location going by the pickup unit.

Hmmm, I must admit it was a couple of years ago that that happened, so I'll have to put the fork sensor on again to make sure I wasn't imagining it

billydonn said:

The exact number really depends on the brand of tire. I think 2090 or 2097 is almost certainly too small in most cases and will underestimate your speed. The box on my Coninental tires gives the number 2122 for their 700x23 but using the rollout test I am using 2115. The rollout test is easy to do and the only real way to go IMO.

Sheldon Brown's Cyclecomputer Calibration Chart

I do not think you have to do the rollout test with the rider on the bike, by the way. I suspect both of your different computers are off by a little.

Thanks for this billydonn. The rollout test seems to be just what I'm looking for! And the figures you give suggest my current setting is way off.

Thankyou everyone😄

Charlie

billydonn said:

I have ridden lots of miles on the CS100 and have never noticed this. There are lots of places on my rides where I have to slow and accelerate so I will pay special attention to that issue today on my ride.

The Polar does seem to be a little fussy about the magnet's location relative to the pickup unit and I HAVE had the CS100 go in to pause mode at high downhill speeds occasionally. (Now that will mess up your average speed calculations for sure!) But I have been able to stop that from happening by adjusting the magnet's location going by the pickup unit.

I have had to put the magnet so close to the sensor that when I ride out of the saddle, the slight compression of the front wheel causes the two sensors to hit each other!!!

Chazzz801 said:

I have had to put the magnet so close to the sensor that when I ride out of the saddle, the slight compression of the front wheel causes the two sensors to hit each other!!!

Get a rare earth magnet or two. They're much better than the kack magnets that come with bike computers and give you a greater margin for error in placement.