Installation/Review: Alnicov GAQ502 Bridge Stabilizer

In a previous article, I had discussed my frustrations with keeping my Fender American HSS Special Stratocaster reliably in-tune while using the tremolo. As you can see, it still has its original vintage “synchronized” bridge installed.

Short of purchasing a Floyd Rose locking bridge system and having it installed by a Luthier which would have easily cost me hundreds of dollars, it seems I’ve finally run across a much more economical magic bullet.

I received this Ibanez BACKSTOP copy, in exchange for a review. Made in China by Alnicov (what isn’t nowadays), it appears to be just about an exact replica of the originaI. All components save the strong stainless steel springs are made of thick brass, rugged and well-designed. It arrived nicely packaged in dense foam, complete with the 3 required mounting screws.

Figure 1: Alnicov stabilizer unboxing

I’m certainly no Luthier, and to my dismay this product came with no instructions of any sort. The seller was also of zero help, so I had to make the Internet rounds at various sites for tips on installation and adjustment of these types of devices, which took longer than actually doing it.

Thus, the inspiration for writing this article… I think I did it as much to help others who may be interested in bridge stabilizers, as I did to remember the procedure I used myself!

I’ve also included a short demo video of my results near the end of the post.

Here’s a better overall view of the unit and its components. The lower thumbscrews control the length of the shafts, while the inner thumbscrews set the “pre-load” tension of its springs. I suggest you play around with these prior to installing the stabilizer, and you’ll quickly become familiar with how they function.

Since I’ll be walking through installation, naturally I’ll be getting into complete details regarding this later in this post…

Figure 2: Tremolo stabilizer components overview

Although I primarily use my tremolo for dives, I like to float my bridge just a bit to allow increasing pitch as well. Fender recommends a 1/8″ (3.2 mm) gap at rear of bridge to the body to accomplish this, but I take it down a little lower than that, almost but not quite “decked”.

Figure 3: Bridge-to-body gap

Here’s a view of my previous tremolo cavity configuration, which was 4 vertically-installed springs with the claw adjusted roughly 1/2″ away from the cavity edge to obtain that small gap which I prefer.

Figure 4: Tremolo cavity prior to stabilizer install

While I’m on the subject, here’s another quick little trick which I use to help further stabilize this type of bridge:

  1. With the bridge pulled back flush to the body, loosen all six screws located at the front edge of the bridge plate, raising them so that they all measure approximately 1/16″ above the top of the plate.
  2. Tighten the two outside screws fully back down.

This allows the bridge to pivot on the outside screws, leaving the four inside screws in place for stability.

Figure 5: Bridge stabilization via mounting screw adjustments

Of course, bridge and tremolo configurations will vary with each guitarist’s tastes. The point here is, whatever your preferences are, these adjustments must be done prior to installing the stabilizer, with the string gauges you normally use in place and tuned to pitch.

I’m not going to get into any detailed procedures for configuring your bridge and/or tremolo here. You can find many articles on the subject via a Google search, as well as on YouTube.

Once installed, the stabilizer will be adjusted to act in concert with the claw to ensure the tremolo block always returns to this rest position and no further forward, thus maintaining much better tuning.

This stabilizer is designed for use with three claw springs, one on each of the far sides, and the third running through the center channel of the stabilizer itself. That said, two springs needed to be removed to provide space for installation. Once that’s complete, the third claw spring will be added.

Since we’ll be removing claw springs, the bridge must be temporarily “blocked” to hold it in the rest position you’ve already set up. I did this by inserting playing cards between the tremolo block and the rear of the cavity, until a very snug fit was obtained.

I then tightened the claw screws slowly, until the cards just slipped out. Turning the guitar over, the gap between the rear of the bridge and the body should remain as before.

Figure 6: Temporary bridge block to allow claw spring removal

To avoid any tapping noise which may have been produced by the stabilizer shafts contacting the tremolo block, I cut a 1.5″ x 0.5″ section of thin adhesive padding and stuck it to the block at the shaft contact points.

Figure 7: Pad cut to size
Figure 8: Pad installed on tremolo block

Prepping the stabilizer

  • Rotate the shaft length adjusters so they are just flush with the ends of the shaft threads, which will maximize their length.

Alternately, you can rotate their thumbwheels in a bit to allow for a little more adjustability. Either way, check to ensure the shaft tips protrude through the stabilizer frame equally. A slight tweak of one of the length adjusters may be required to accomplish this.

  • Fully back out the spring tension adjusters, so their springs aren’t under load.

Reference Figures 1, 2, or 7 above for clarification of these starting adjustments before proceeding.

“Roughing in” the stabilizer position

  1. Place stabilizer into the cavity and slide it towards the tremolo block until the shaft tips are just beginning to push into the pad.
  2. Since the stabilizer has obviously not yet been secured, lay a third claw spring into its center channel. Do not install the spring into its normal position at this time, as that would block stabilizer mounting screw installation.
  3. Viewing the claw spring’s hook and pin as if normally installed, move the stabilizer to center the spring in its channel as closely as possible, to avoid it rubbing the interior of the channel.
  4. Holding it in that position, mark the corners of the stabilizer body using a Sharpie.

Finishing installation

  1. While firmly keeping the stabilizer aligned as you’ve just marked it, use a small nail to create an indentation precisely at the center of the middle hole, where we’ll be installing the first screw. This will allow for pivoting the body a tad, just in case the claw spring position is a little off-center in the stabilizer channel.
  2. Using a 1/16″ drill bit, carefully bore a shallow pilot hole to prevent cracking the wood surface when the screw is installed. This was the perfect size for these particular screws, but may vary with those supplied with other stabilizer brands. What’s extremely important is that you use a drill bit that’s at most a quarter size of the screw diameter, to prevent stripping and/or the stabilizer pulling out of the wood.
  3. Insert this screw into the pilot hole, ensure the stabilizer body is aligned with your marks, and fully tighten it.
  4. Install the remaining two mounting screws in the same manner as the the middle one.
  5. To prevent any noise from the third center claw spring, lubricate it to move smoothly within the stabilizer channel by applying a generous coat of beeswax, completely covering its outside surface. I suggest using this in lip balm form (such as “Burt’s Bees”), as it’s soft and easy to apply.
  6. Finally, install this spring as you normally would.

Installation of the stabilizer is now complete.

Final stabilizer adjustments

Now comes the tricky part: As described at the beginning of this post, tremolo stabilization is attained via a balance between claw and stabilizer spring tension. When properly adjusted, they will work together to control block travel distance in opposite directions.

Double-checking shaft clearance

The stabilizer should not be part of the equation when moving the tremolo arm down (“dive bombing”), during which the block is moving backwards. Its return must remain the job of the claw springs alone, with no interference from the stabilizer.

If the stabilizer shafts move towards the block at all when the tremolo arm is depressed, they are too long and must be shortened using the shaft length adjusters, until just pushing into the pad as before.

“Pre-loading” shaft springs

Using your favorite tuner, bring all strings to pitch. Leave it connected, as it will be used to monitor tuning throughout further adjustments, described below.

The tension of the stabilizer springs must be increased equally (“pre-loaded”) to provide enough strength to stop the block at the identical position every time the tremolo arm is depressed and released. This prevents any further forward movement of the block while at rest, keeping the guitar from slipping out of tune.

To accomplish this, increase “pre-load” equally using the spring tension adjusters as much as required. As pictured below, I needed to move them approximately 1/4″ upward on the shaft threads. You may need to also slightly tighten the claw springs to retain the balance between the two.

Stabilizer and claw spring adjustment complete
  • Note: If you float your bridge as I do, turn the guitar over and press down on the rear of of it with the palm of your hand. Pitch will of course rise, but should remain in tune when released.

Achieving this balance requires patience. Make small, alternating adjustments to stabilizer spring “pre-load” and the claw as required until everything is operating as described above, then once again re-tune. When properly configured, strings should return to pitch after moving the tremolo bar in either direction.

At this point, you may find the tremolo bar “action” to be too tight or loose, which of course is a matter of personal taste. To remedy this, experiment by varying spring tension adjustments once again, until the “feel” is to your liking while maintaining the proper operation of the stabilizer as I’ve just described.

Once you become familiar with the relationship between stabilizer and claw spring tension, it’s not as difficult as it may sound. All of these adjustments took me only around 10 minutes to dial in, with excellent results.

Okay, you’re all done, but will the result be perfect? The answer is no, because nothing in life is, not even that previously mentioned expensive Floyd Rose system.

However, I can say without a doubt that this little device has made a huge improvement in the ability of my Strat to remain in tune, even after deep tremolo dives.

A short demo using the high-E string, which previously was always prone to falling out of tune

In summary, unlike installing a custom locking tremolo system (not to mention a locking nut and tuners), it’s far from a major modification since it requires only three small holes in the tremolo cavity.

If for whatever reason you’re not satisfied with its performance, uninstalling it would take only a few minutes. Except for those three tiny holes now hidden under the tremolo cover plate where no one will ever see them, your guitar will be just as it was before.

Best of all, as I had mentioned it’s extremely economical: The price of this product is a mere $35. If interested, you can check out its Amazon product page here:

Alnicov Bridge Tremolo Stabilizer

It’s available from various other retailers as well. I found many for sale on eBay at even lower prices.

Any additional pointers or questions on the subject of tremolo bridge stabilization? Please, feel free to leave your feedback in the comments below!

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