The case against Fender’s Micro-Tilt

Today, I’m going after one of my least favorite features on the world’s most popular guitar: I’m making a case against Fender’s Micro-Tilt. Fender introduced the Micro-Tilt in the early 70’s, and this has been causing problems with their necks for over 50 years. This was designed to angle a bolt-on neck back in the pocket, allowing for lower action and making up for discrepancies in build accuracy. Most haven’t even questioned this design, yet we feel that it causes necks to bend and kink in a critical area around the heel, causing strings to buzz and choke out. I have a hypothesis, test subject, and procedure, so let’s SCIENCE!

I recently refretted a Mexican made Fender Telecaster (which is a great bang for your buck), and the fretwork was now as perfect as possible. When we refret a guitar, we true the fretboard with our PLEK machine, which cuts the fretboard level with an accuracy of .1mm. Then we press and glue the frets in, bevel and dress the fret ends, and then level those frets with the PLEK (accuracy within .01mm) before giving the guitar a complete setup. This is the best way we’ve found to do fretwork – we’ve done thousands of guitars by hand using our custom neck jigs prior to using the PLEK, and the results are more accurate and consistent by far. This Telecaster played perfectly clean with our standard low action of 1.5mm(bass side) and 1.25mm(treble side), and would be a great test subject.

Here’s how the Micro-Tilt works: the screws holding the neck in the pocket are loosened, and then the bolt in the center is turned to push up against a steel block in the heel, which raises the neck away from the pocket, and then the neck screws are then tightened back down, which angles the neck back. The trouble with this is that this creates an air pocket under the heel, and the heel isn’t supported fully against the body. The force differential between the Micro-Tilt and the neck screws causes the neck to bulge and bend, compromising the accuracy of the fretwork. The Micro-Tilt is pushing against the heel, while the neck screws are pulling down. Something has got to give.

Here’s a scan from our PLEK machine after the refret, which shows all of the frets even within a few thousands of a millimeter of each other. This is what a typical final scan looks like, within spec and every note playing clean. This is without any neck tilt applied.

Now I added some Micro-Tilt adjustment. I raised the Micro-Tilt up .5mm above the plane of the neck pocket, put the neck back on, tuned it to pitch and scanned in again in the PLEK.

This took less than two minutes to do, and the detrimental effect of the Micro-Tilt was immediate. With the same action, the guitar now buzzed and choked out in the upper registers. The scan shows now that the neck has bulged in the middle, pushing notes on the G and B strings out of spec (the frets surrounded by triangles indicate fret buzz). While it has created some rise on the high E string, it’s not quite enough to push it out of spec into buzzing territory, but it’s close.

This proves that the Micro-Tilt causes problems. Sure, the angle of the neck has allowed for lower action, but if the fretwork is compromised it makes low action a moot point. The notes aren’t going to speak as they should, making the guitar play worse!

In the interest of science, I also tried this experiment with a partial neck shim. I lowered the Micro-Tilt back down, then cut a piece of .5mm maple veneer, put it into the neck pocket, and repeated the scan.

The partial shim is even worse! The guitar is buzzing like crazy on the G string, as well as in multiple places on the B and E strings. The partial shim kinked the neck all the way across, as opposed to bulging the neck in the middle like the Micro-Tilt did.

We now have demonstrable proof in the case against the Micro-Tilt. It’s a problematic design, and has been ruining your necks for decades. The Micro-Tilt and partial shims kink necks in a critical area, and worse that over time they can create a permanent bend in the end of the neck, forcing a full refret when otherwise simply a fret leveling would do.

We’ve heard some… shall we say, spirited debate about this in the comment sections of our Facebook and Instagram accounts. Some of these arguments have been reasonable and intelligently stated, while others sounded more akin to “Nuh-uh!” Several people said that moisture getting into the neck heel through the screw holes and/or truss rod access made a bigger difference which, quite frankly, I found rather absurd. First of all, how much moisture from the air even going to get into those screw holes, which are plugged with the screws themselves? Also, oftentimes those holes are waxed, making moisture infiltration even more ludicrous. And if moisture is getting in through the truss rod hole, why isn’t the entire neck swelling along the length of the truss rod? And what about guitars that have trussrod access at the headstock rather than the heel – why are they still kinking at the body joint? So, just to humor all those moisture conspiracy theorists, I also flooded the neck heel screw holes with water and let it sit for several hours. This was far more moisture than could ever be reasonably assumed would get in there, but I was proving a point. And the results were as I expected: a subsequent PLEK scan showed absolutely NO difference.

Now, we are under no illusion that guitars are entirely stable. They are made of wood, and are under around 100-200 pound of string tension at all times, and this can cause them to move and distort. Yes, neck kinks like this can happen on guitars without a Micro-Tilt or partial shim, even on set neck and neck through instruments. And sometimes you might get lucky with a neck that doesn’t bend much when the Micro-Tilt or partial shim is applied. But! Micro-Tilts and partial shims can actively make the instrument play worse. Therefore we actively discourage their use. So what to do? The easiest solution is to use a full pocket shim, such as the ones sold by StewMac. These angle the neck back while fully supporting the heel, leaving no air pocket nor force differential and keeping the neck kink-free. Another much more complicated way is to reshape the neck pocket with a router, but this involves a lot of math and a great degree of skill to do correctly. We’ll do it for you if you’d like, but it’s going to be far more expensive than a $10 full pocket neck shim.

So there you have it – I feel I’ve made my case against Fender’s Micro-Tilt. We as a rule NEVER use it in our shop, and whenever we have a guitar come in for fretwork we automtically inspect the neck pocket for Micro-Tilt adjustment and partial shims, and remove them when we find them. We encourage you to do the same.