GPS question

To all you GPS geeks (like myself) I pose this question:

I have a Garmin III+. I have a handlebar mount for it but I decided I did't want to subject it to all that vibration especially in the (un)likely event of a crash. So I bought an antennae extender for it, mount the antennae on top of my camelback, and put the unit in a fanny pack for easy access.

After riding with it for a couple of months, it crapped out. I had to sent it back to Garmin for warrantee work. They were quick with it's return. It turned out to be a loose connection that they had to solder.

I know many folks have their GPS units hardened to protect it from this kind of vibration damage. Many users on this site have had their units hardened and have no problems with it even when mounted on the handlebars. A-Loop provides this service for a reasonable fee.

However, when I first bought my unit I e-mailed Garmin with questions about he hardening procedure. They told me that they will not warrantee a unit that has been hardened. I'm not sure what to do? If I have it hardened, can the electronics still be accessed if it needs service? Have any of you had problems with a hardened unit? (don't go there Kevin and Mitch)



I have had problems with my hardened unit. It usually occurs when I wake up in the morning or when my wife is present. Occasionally it has been know to act up during a "Baywatch" episode.

I'm not so sure I want to get involved with this thread, but being a major gps geek and knowing the answer to the question, I feel compelled to help Bryan out.

Once you harden the GPS receiver you can not get to the electronics. They basically fill the thing with epoxy. You can do it yourself with a spray can of insulating foam (Home Depot).

I would not recommend doing this. I have had a problem with my GPS receiver where the external antenna connects to the fake bnc connector. The wire inside tends to twist itself off, and I had to solder it back on. I also used a generous amount of epoxy glue to make sure the built-in part of the bnc connector could not move again. This problem is due to connecting and un-connecting the external antenna to the wimpy Garmin bnc-type connector, and not vibration.

Only "harden" the receiver (notice I'm using the word receiver and not unit) when mounting on the handlebar. If you are using a fanny pack type deal, make sure it's protected in some kind of padded case (a cheap-o camera case works best) and DO NOT perform the hardening thing. You may want to open that sucker up and epoxy glue the wimpy connector so it can't twist and break. I've logged many many tough miles with a few major get-offs without damaging the receiver (or unit, thank God).

Good luck!

Bryan, dont worry, I wont bite. And Ketty, shame on your for getting there before me. :)

Hardened units, never have problems with that.It hardens up at the most unpreDICKtable moments. :D

Seriously though. What do you mean by hardening? My thoughts are as follows:

Mount from behind. Meaning that when you mount the unit on the bar, make sure you use some antishock foam or somehing to that effect to reduce the vibration. It is not the hard pounding that is making it loosen prematurely, it is the constant vibration.

Dont tape it heavily or permanently appoxy it as it may effect your warranty.

Good luck


I've never mounted my handlebars with a hardend unit.....and I'm not sure I'd like to!

I think there are special clothes for something like this (problem?).


99 WR, all YZ mods, de-octopused, OEM YZ tank and IMS seat, jetting by Clark, got forked by Pro Action, WAITING IMPATIENTLY FOR MOAB!!


Bryan - you really stepped into one this time. These guys have been waiting for a chance like this. Be smart and just delete the post. The jokes could go on for weeks. And you definitely don't want them showing you their hardened units in Moab.

Never mounted my handlebars but man have I inadvertently mounted my gas tank a few times and it resulted in some pretty bad GPS of my own (gashed penil syndrome).

This usually happens when my front wheel meats a tree root sticking out the side of a trail.

And trust me, there is no hardening of the unit for quite some time after that.

Bryan, take Ron's advice and don't send your unit off to a professional for hardening. I'm sure you can do it yourself quicker and cheaper.


Dougie, '99 WR400

Mods: YZ timing, Race Tech Suspension, FMF PC IV, FMF Hi FLo Moto, YZ seat, IMS 3.3 tank, One Industries Graphics, Renthal bars, 14/52 gearing.

Thanks guys (I think). Ron, I was hoping you would answer this post (the GPS guestion, not the other comment). That was my thought too and Garmin concurs.

I'll be riding with Dougie this weekend. If I can get some pictures of him mounting his gas tank, I'll post them for you to see.

Or maybe they can go on the ThumperTalk t-shirt?


Bryan, your very welcome....

I hope you saw the benefit from my posting? After all, you dont want to get in trouble with your lovely wife.

Love ya Mate...


You need to check the web site for

These guys have been using GPS for mountain bikes and motorcycles for a while now. They will vibration isolate your GPS guts for $35.

The real benefit for GPS is having the thing visible so you can use it while you're riding.

I have a GPS III plus on my 98 WR400 and use it as my odometer, speedometer and map. I have over 2500 miles on this set up and the only problem is you have to use an exteral power cable. Engine vibration will cause the batteries break contact and the GPS will be turning off constantly.

External cables from Garmin are way too expensive. Do a web search for a company called

Blue Hills Innovations

the make all types of cables for the garmin GPS line.

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