Best Replacement O-Ring Material for Garmin HRM?

5952037 26 days ago

Hey everyone,

I’ve been searching for replacement parts for my Garmin HRM Heart Rate Monitor, and I noticed that the red O-ring covering the sensor pod is starting to wear out. I found a replacement available on this site, and they mention that it’s made from silicone.

I wanted to check—is silicone the best material for this O-ring? I know that O-rings can come in different materials like rubber, nitrile, or even fluorosilicone, and I want to make sure I’m getting something that will last and perform well.

Has anyone replaced their HRM O-ring before? If so, what material did you go with, and did it hold up over time? I’d love to hear your thoughts!

Thanks in advance for any advice

0 rinserepeat 24 days ago

there have been a few previous threads on O rings for all the Garmin HRM which seem to eventually fail, especially the HRM-TRI which breaks after the first or second battery replacement and was discontinued likely for that reason

(oddly my HRM-Pro-Plus is surviving after a dozen battery replacements and the O-Ring appears the same as the HRM-TRI)

https://forums.garmin.com/sports-fitness/running-multisport/f/accessories-sensors/232645/hrm-tri-o-ring

here's an info-dump of everything I've collected on it and yes it has to be soft silicon so it seals

Garmin's own specs/part-number:

O-Ring

19.05mm x 1.168mm, 50A Drmtr, Red Silicone

251-10083-00

the important measurement is actually the INNER diameter (not outer)

and it's not metric but rather 3/4th inch (0.75 inch) which is about 19.05mm

however the thickness is the problem, the factory one is some weird number like 1.168mm

and 1mm rings are too thin while 1.5mm rings are too thick, you have to find something inbetween and they cannot be "hard" material but softer silicon, etc.

https://www.youtube.com/watch?v=62wb7rmt-LI

https://mytriaddiction.wordpress.com/2017/07/10/garmin-heart-rate-monitor-repairs/