The A4 XC Stem

Interloc Racing Design (IRD) is a small US bike maker that has been in existence for 20 years. Renowned for their innovation and craftsmanship in bicycle components as well as bicycle frames, the small California based firm frequently introduces new and interesting ideas to the biking industry. Their more interesting product recently will include the MetaWire, 16G Cages and Black Lightning Cogset.

The IRD’s A4 XC stem is their top of the line stem built for both competitive road and cross-country use. It features a single piece CNC’d aluminium construction coupled with quad bolt removable faceplate and an opposing bolt configuration at the steerer clamp.

Careful observation will reveal that the A4 packed most of the latest developments in stem design within its nifty package. For starters, the one-piece construction ensures that there are no welded joints to fail. The 4-bolt, single piece faceplate is able to deliver better clamping might but with lesser stress on the handlebar as compared to a 2-bolt design. The two opposing bolt at the steerer clamp ensure a more even clamping force on the steere tube. Lastly, excess material is perforated at both ends to keep A4 lean and mean.

Practical functionality is not the A4’s only forte. Its sleek aesthetic goes well with any race ready cross-country and road bike. All graphics on the stem are laser etched to ensure they last a lifetime. Our only whine here is that the A4 only comes in matt black. While black is a common colour, you can forget about the A4 if you are building a fanciful bike.

Going for the Ride

The test stem we had measures 100mm in length and has a +/- 5 degrees rise and weighs a respectable 163g on my kitchen scale. Not the lightest stem out there but if you are looking for featherweights, you are looking in the wrong direction anyway. The A4 is design to function and to last.

Mounting the stem to our test bike was a breeze. Both the bar and steerer hook on to the stem like a glove. Just remember not to tighten the faceplate excessively. A 4-bolt faceplate generally requires lesser tightening torque as compared to a typical 2-bolt design. If in doubt, refer to the mounting instruction that comes with the stem.

Once installed properly,you can pretty much forget about it. The stem felt really stiff and confidence inspiring when in use. However, we do feel that steerer clamp area could be more ergonomically designed. The bolt mounts at the steerer end could cause potential danger during a ride whereby the rider’s knee might hit it accidentally. It will be ideal if IRD can give it a more rounded profile.

In our three weeks of usage, everything was held neatly in place by the stem. After going through all the trashing we gave it, the stem still look as good as new on the day that we were returning it. The only tell tale sign that suggest the stem was used was the dirt stain on the white-based laser etched graphics.


Stem might be a pretty simple piece of component as compared to the rest of the bike parts. Nonetheless, never underestimate the amount of engineering work needed in designing one. IRD had done a good job with the A4 by employing the latest innovations throughout the design of the stem. Together with top notch finishing and sleek aesthetic design, this piece of equipment is a sheer pleasure to own.

Some of the improvements that we would like to see are more colour choices, a more rounded profile at the steerer clamp and small weight lost program. We are not implying that the stem is overweight, but intuition tells us that the A4 can still afford to slim down a teeny bit with no compromise on its durability or functionality.


CNC’d Aluminium
Quad bolt removable clamp
Oppose bolt configuration on the steerer clamp
Rises 5? (flip-flop)
1-1/8” steerer clamp
Average weight: 159 grams

Check out IRD’s website Interlocracing for the complete list of components they have to offer.