May 022012

Update April 2013: There is an improved version of this custom Aerobar Computer Mount – please read this post for more details.

There are several options to mount a Garmin Edge cycling computer on a standard road bike. However, on a triathlon bike, things are not that easy. You could mount the computer on your stem – however, this option is not compatible with bottles mounted between the arms which is the most aerodynamic solution. Another option would be to mount the computer on one of the extensions. Yet, this would be a poor choice in terms of visibility. There is a quite exhaustive thread in the Slowtwitch forum which discusses several options and custom made solutions. I want to share mine ;-).

I took a carbon fiber plate and marked an octagon shape on it.

This was put into a standard bench vice.

The easiest method to cut straight lines into carbon fiber is to use a Proxxon / Dremel machine with a cutting wheel.

In approximately three minutes, the cuts were made.

The next step was to drill two holes each on the left and the right side to accomodate the cable ties.

Afterwards, I took a standard Garmin Bike Mount. However, the extensions of the mount to fit the rubber ties are somewhat redundant.

So I removed them, again with the Proxxon and a cutting wheel.

The result after a couple of minutes – pretty slick.

The trimmed down Garmin Mount will be glued on the carbon fibre plate.

The final mount after gluing.

Mounted between the shifters at the front end of the extensions using two cable ties.

And with my Garmin Edge 500 placed in the mount.

Just on one level with the top end of the extensions.

The weight of the bike mount including the cable ties is just 1g more than the standard Garmin mount including the rubber ties.

In total, it took me about 60 minutes to build the computer mount and I am confident that this is going to be a durable and well working solution.

Apr 152012

Since August 2010, I use a Garmin Edge 500 cycling computer on my triathlon bike, my mountain bike and in a couple of weeks also on our Chariot Cougar Child Carrier while running. November 2011, I bought a Sony Xperia active smart phone since it basically can do everything that my Garmin does: It is ANT+ compatible, features an integrated GPS receiver and even includes a barometer. There are plenty of sport apps available for Android which can be used for running, cycling and plenty of other activities.

Because the Xperia active can be paired to all the existing Garmin ANT+ sensors on my bikes, I thought that it might be a good idea if it could also “pair” to my existing Garmin bike mounts. With this blog, I would like to show you how I achieved just that.

First of all you’ll need an extra cover for the Xperia active. I bought the Billabong edition which included two extra covers.

After that, I measured the dimensions of the Garmin Bike mount.

I figured that I would need two plastic discs to replicate the Garmin mount. The first one should have a diameter of 25mm and a thickness of 1.45mm. The second one should also have a diameter of 25mm, but with two extensions of 1.25mm lenght and 10mm width. The thickness of the second disc should be 1.75mm. I chose carbon fiber as the material, but any other plastic should be fine as well.

Now I needed to glue the two discs on the cover – I chose UHU plus to do so. Essentially, UHU plus is a 2K epoxid glue which can be cured at 70°C in 45 minutes.

During my first attempt to glue the carbon discs onto the cover, I took a clamp and fixed it to my desk.

Afterwards, I used a hair dryer to speed up the curing process.

While performing a static load test, I had to realize that before gluing, I should have removed the Billabong graphics on the cover because this was the breaking point. So I took the second cover, scratched of the graphics and glued the carbon discs for the second time. To ensure a proper curing process, I put it into our oven at 70°C for 45 minutes.

This time, the result was better withstood the static load test.

Sony Xperia active – mounted to our Chariot Cougar using a standard Garmin bike mount. Nice!

Of course I am going to start the Xperia active during cycling from now on. I will report about the long term reliabilty of this bike mount.

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