bikerjp

I've been using this for about a year and have only once or twice before seen a spike in HR. Lately I'm seeing them quite often. I'm doing everything the same: wet electrodes before starting, same clothes, battery was replaced though it has been a while (if battery I would think the issue would be more dispersed rather than just at the start of the ride).

I know the static theory and don't think that's it as I've not really seen this problem before and the clothes are the same. I did start to use a wool base layer, but I had that for a while before the problems started.

Has anyone seen a similar issue and pinpointed the cause?

saintsfaninks26

I have had the same issues with my Garmin 500 and it always happens only at the beginning of rides. I have found that it usually happens when I turn the computer on and immediately start my ride. What has helped me is that I now turn the computer on before I am quite ready to ride and the computer picks up my heart rate before it is elevated, usually in the 80s or so. Then when I jump on the bike it goes up to where it should be instead of in the 240s.

My theory is that the Garmin needs to somehow calibrate to your heart. If you are already exerting yourself when it starts reading it assumes that is somewhere near your regular heart rate and it goes up from there. I could be completely wrong but letting the computer pick my heart rate up for a few minutes before exercise has kept mine from spiking like that.

If you figure out the real cause let me know.

jmX

Turning the computer on has nothing to do with what HR the strap sends out. The strap itself is what is calculating BPM, and it broadcasts that number. The computer is just displaying it.

Try some heart monitor gel, or put your strap on long before you exercise. Dry skin -> dry contacts + wind seems to really cause the spikes for me. Even with gel, you may still have spikes here and there in the first half hour of a workout, and you may just have to ignore them.

Are you using the "premium" strap where its 95% stretchy cloth with a small plastic module that snaps on, or are you using the strap that has a huge rubbery plastic section a foot wide in the front? My premium strap would have the spikes a lot more often than the cheaper one, which is what I now use all the time.

gettingold

Recently showed a 245 right at the beginning of the ride on a downhill. I figured it was a wind/dry electrode issue. It hasn't happened since, but I got a crazy spike on my cadence the other day.

bikerjp

I have the premium strap and have been using it without issue. I've seen maybe 2-3 spikes over the last year and it was usually just a single spike during a ride. Now I'm getting multiple spikes. I don't use gel, but I do make sure everything is damp and the electrodes are "sticking" to my chest. Also at least 5-10 minutes between turning on the unit and starting the ride. The data above covers both down and uphill sections during the spikes.

I'm starting to wonder if maybe it is just a battery issue. Just odd that it's clustered. Maybe a weak battery is more susceptible to wind and dry(er) electrodes and later in the ride that all settles down more so the weak battery can cope.

jmX

Sounds exactly like how mine was. I think humidity and wind is a factor, maybe static electricity too? Either way the cheaper garmin strap has been great. My premium one stays in the drawer now.

ddimick

I also had the same issue with the premium strap. Using a Zephyr HxM strap instead now with zero issues.

Adrianinkc

Garmin knows of the issue, give them a call and they will replace it.

mlamb01

Had the same issue with my premium strap and my Wife's... Our premium straps had the snaps on the transmitter that were used to open the strap, and also make the connection. We both got the new premium strap(re-used the old transmitter), and all is good now. No spikes at all... This strap fastens by sliding a loop over a hoop on the side of your body. Its also more comfortable IMO... You can find them online for $35.

bikerjp

This may be the case. I decided to see if it was a battery issue. Replaced it an went for a ride. Spikes at the end now. I'm pretty sure I never hit a 216 HR so maybe it is defective. Odd thing is it worked fine for quite a while. It is the newest one with the loop and hook attachment.

Beaker

Any chance it's loose clothing flapping against the strap?

bikerjp

Can't say 100% "no" but I've had this for about a year and never had this issue and the clothes are basically the same. In fact, I've started to wear a base layer most of the time and it's snug. Also thought maybe the wool layer might be the issue, but the probably started well after I started using the wool. I've email Garmin support so we'll see what they say. I have another strap that came with my daughter's Forerunner so maybe I'll give that a try and see if the issue stops. That would more or less point to a problem with the unit. I'll try that tomorrow.

Nachoman

I had similar issues and I hand washed the strap and monitor with soap and water and haven't had problems since.

icyclist 

If I touch the strap while it's on my body, readings immediately skyrocket, then slowly return to normal. I've also had spikes while riding downhill - I'm guessing the flapping jersey is somehow the culprit.

Lots of info/tips about this issue are here.

MikeyBoyAz

I have the larger rubber strap and I have noticed that if I wash it off (thoroughly with copious soap etc) it reads crappy the next time I use it. If I just wipe it off with a wet wipe it reads perfectly.... salt conducts when mixed with water I suppose, and if you wipe it off...



ahh... what nacho said.

bikerjp

Tried a different unit on the same strap today and also adjusted the strap to be a bit tighter. Got this.



Still one spike. That does happen occasionally so I'll see if it happens again. If I keep seeing this, however, then I wonder if the problem is more strap than unit. In the dcrainmaker link above he suggests using a polar strap to solve the problem so maybe straps can go bad or something.

zigmeister

Exactly what i just did. Had my old bluetooth zephyr strap in the drawer. Garmin strap was reading 250bpm.

Switched strap, working perfect again. Garmin strap now in garbage.

People swear by the Polar straps as well.

roadrider63

This is my second year with the garmin 500 and premium strap. I've also noticed more spikes and abnormal readings this year than last. Even on the trainer I get many abnormal readings. I just don't remember this happening as often last year.

Before I switched to the garmin I had a timex watch/hrm and remember very few spikes with that strap. I'll have to see if it works with my garmin or contact garmin and see if they can offer some assistance. Just glad to see I'm not the only one seeing this happen.

icyclist 

However, some people commented that getting the new strap didn't work, either, and some claimed cleaning off the contacts with vinegar did.

I think the secret, for me, is to put the strap on several minutes before I start to ride. This gives the transmitter time to calm down (it goes a bit bonkers with high readings when I touch it directly or even through my jersey. AND I keep the strap reasonably tight.

bikerjp

I'll try the vinegar trick before my next ride. Thanks for the tip. I also put mine one several minutes before I start and I did tighten it up some. Seemed to help some but a few more trials are needed to be sure.

trustnoone

I did this three days ago when I started seeing spikes. Seemed to be a fix for mine.

Looigi

Did anybody mention the flapping jersey phenomenon? A dry flapping jersey can create static electricity which can interfere with the HRM. Some have found that spraying their jersey with Static Guard anti cling spray helps. I haven't tried this myself so just throwing it out there for your consideration...

eugenek

I was riding in windy weather last weekend and I noticed this. When riding downwind or standing still, readings are nice and smooth (for example, staying in the 142 to 155 range continuously for 45 minutes and at 150-152 most of that time). When reading upwind, readings are spiky. At first I was getting a bit scared when it was showing spikes to 180-190 (even though I didn't feel anywhere close to 190.) Then it spiked up to 218 and eventually to 238. At that point I was pretty sure that it was a sensor glitch.

Like others said, it looks like a combination of excessively dry skin (dry air and head wind can wick away moisture faster than you can sweat) and possibly a flapping jersey.

bikerjp

I've continued to have issues. Garmin support is sending a new strap. I tried all the various fixes but basically it's a problem that did not exist before so apparently the strap went bad. Not sure how or why as I take care of it but seem to have.