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How to create a bicycle bar extension out of a stem adapter

In this article I’m going to explain how to use a stem adapter as a bicycle bar extension hack.

lifeproof bike mount attached

I often ride in places where I have to rely on navigation to find my way. I have an iPhone and a LifeProof LifeActive bike mount so I can use specific apps handsfree.


If you can’t place a bike phone mount on the stem, which is the case with the very wide Syncros Cattleprod stem, you’re forced to look at an asymmetric setup.

Video Tutorial

Bar Fly Universal Mount

bar fly universal mount
Bar Fly Universal Mount with LifeProof LifeActive Bike Mount

I think an asymmetric setup looks ugly, and it’s also one of the reasons I run two lights on my Killer V, with the phone mounted on a Bar Fly Universal Mount in the middle.

However, this Bar Fly Universal Mount is made out of plastic and attaches to the bar in just one place. This means it’s unusable to accommodate the relative high weight of the smartphone on anything other than tarmac.

The mount simply is too flimsy to support the weight on rougher terrain and would bounce all over the place, with the possibility of the smartphone disconnecting from the mount.

TransZ Stem Adapter

transz stem adapter

I looked at several options that were best suited for the Syncros stem and decided to go a less intuitive route and choose the TransZ stem adapter, which costs €18.

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Whereas you’d normally use this to be able to rotate your handlebars up and down, the two clamps and small tube are the perfect solution to hold a bike mount.

The stem adapter is made to hold the handlebars with the rider’s weight of the arms resting on them, so you can be rest assured that the weight of the phone and bike mount alone will never move it once installed.

Installing the stem adapter

stem adapter width

Installing the stem adapter, although finicky, was straightforward enough. The only issue I had was that the Syncros stem was wider than the adapter. And when I moved the clamps outward to accommodate for this, the plugs didn’t reach the insides of the small bar and simply fell out.

stem adapter plug

I sawed a small aluminum rod at the correct length that fit perfectly into the plugs and pressed them into place. Problem solved.

Concluding remarks on the bicycle bar extension hack

This bicycle bar extension hack not only works fantastic for a relatively good price, it doesn’t look out of place as well on this vintage mountain bike.

I might use it for my Cannondale Super V as well.