Introduction: Super Cheap DIY Stem Mount for a Smart Bike Light

About: I studied Electrical Engineering and a lot of other things. I'm always driven by my passions. Please visit also my Youtube channel.

Hi there and welcome to my 'ible' #52.

Smart Bike Lights brand is very popular amongst cyclists (at least in the U.K.).

I bought a lot of these products in the last 14 years (for my commuter, my road bike, my son's bike, etc., etc.).

The products are sturdy, reliable and affordable.

During the winter season early in the morning and in the afternoon, it's pretty dark and you need to be seen from motorists, if you want to have a safe commute to work, or simply a training session on the road bike.

Of course, on the bike you use for "the daily battle" (aka commuting to work), you can throw on nearly everything...

it's not a matter of aesthetic, but functionality.

It's a different story when you are riding a road bike (for training purposes), as you want to be aerodynamic as much possible... or, at least, you want to put accessories on your roadie that make your bike cooler. :-)

If you have a Garmin, you can easily mount your front light under it.

There is a catch, though. The support costs $24.99 (pc mount).

I don't own a Garmin.

I use my smartphone to record my training sessions and I just needed a cheap stem mount, so, I thought:

"Why don't you build one?"


For this Instructable you need:

1x front light mount

(if in the future you want to re-attach the light to the handle bar, I recommend to buy a spare one for 4/5$)

1x back light mount (again, you can find easily this item on Ebay, for 4/5$)

1x M4 nylon screw and bolt (flat head)

1x cutter/exacto knife (please be extremely careful when you use this tool)

1x screwdriver

2x zip ties (preferably in black)



Step 1: Disassembling the Standard Mounts

As I previously stated, you need 2 mounts (front & back), to build your stem mount.

Unscrew the upper part you'll use, to lock your front light.

Unscrew the posterior support, because you need just the bracket.

The parts on the left in picture 2, are the ones you need to build your stem mount.

Step 2: Assembling the New DIY Stem Mount

Using the screwdriver, make a 4mm hole at the centre of the bracket.

Using the screwdriver, make a 4mm hole into the support, that locks the light in place.

The bolt is flanged, therefore you need to cut it until it sits perfectly in the squared groove of the locking support.

Screw the flat head screw inside the bracket, until the bolt is tight and it sits in the groove.

Using the cutter, remove the part that stick out of the support, until everything is perfectly flat.

Drop a bit of superglue on the bolt.

Using 2 zip ties, secure the bracket to the stem.

Be sure to use the rubber straps come with the standard mount (please take a look at the 2nd picture in Step 1),

in order to increase the grip between the bracket and the stem.

Once you lock the front light, you'll notice there is a bit of gap between the head of the light and the stem.

I've just glued a 3mm piece of rubber under the head of the light dumping eventual vibrations. ;-)

Step 3: Congrats! You've Built Your Stem Mount

Congratulations! You have built your super cheap stem mount for your Smart Bike Light.

Even my son told me that in this way, the bike looks cooler. ;-)

If you want to be sure the light does not rattle (due to vibrations), just glue a rubber strip under the head of the light.

Step 4: Upgrade...

Unfortunately, after a few rides, the plastic screw/bolt that was holding the support broke.

To sort this problem out, I've replaced the screw and the nut, using metal ones.

Obviously, cutting it to size using the hacksaw and flattening the screw and bolt using a file.

Anything Goes Contest 2021

Participated in the
Anything Goes Contest 2021