Setup: How much Trussrod, How much bridge???

HiFi · #1 02-19-2005, 12:23 AM

I just did a trussrod adjustment and will probably do one more quarter-turn tomorrow to get the neck just right. I also adjusted the bridge saddles so that the strings line up with the curvature of the fretboard. I had to lower the E string to do this and created some buzz (the reason I will probably do another adjustment tomorrow).

While doing this, I got to thinking, how much should a bassist doing a setup rely on bridge saddle height and such, and how much should they rely on the trussrod to get the strings right. I realize that the trussrod is more significant in regards to the integrity of the neck, but is it a big deal to adjust the bridge a considerable amount to get the action and string position right?

Hope this makes some sense.

gapupten · #2 02-19-2005, 01:16 AM

The best discussion is in the all truss rod and action questions answered here thread. But generally, you adjust the truss rod first to get the correct bow in the neck so that you have no string rattle. Then adjust the action with the saddle.

HiFi · #3 02-19-2005, 02:02 AM

Thanks. I had been looking at those sites previously. I guess I'm wondering about bassists who may have the saddles screws set very high to reduce buzz rather than adjusting the trussrod. Just wanted to see what different setup preferences were out there if they varied at all.

Metal Mitch · #4 02-22-2005, 06:36 PM

Don't think of the truss rod as an action adjustment tool. It's not. All it does is adjust the neck so that your action is more even all the way up and down the fretboard.

If you refer to the Gary Willis method linked in the sticky post, first you lower your strings to get them buzzing. Then adjust the truss rod with the goal of getting them to buzz evenly all the way up and down the neck. From there you use the bridge saddles to adjust the action.

Personally, I find the GW method very imprecise. But it's a good illustration of the relationship between the truss rod and the bridge.

If you want a precise method, get yourself a capo and a set of feeler gauges and follow the instructions found in the BP mag setup guide here -

http://66.77.27.26/gear/specs.shtml

HiFi · #5 02-23-2005, 07:14 PM

Thanks Metal. Always looking to learn. I'll check out that link.

Figjam · #6 02-23-2005, 09:02 PM

buzz on frets 1-5 = loosen truss rod
buzz on 12+ = raise saddles

too much relief = tighten truss rod.

Magneto · #7 02-23-2005, 10:45 PM

I've been trying to think of the best way to describe this without going into a lengthy post.
Trussrod: For adjusting the small amount of forward bow (relief) that all basses must have for the strings to vibrate properly at the middle fret areas.
Saddles: For adjusting the actual string height.
Neck tilt adjustment or shim (bolt-on necks): For changing the angle at the neck pocket, which can bring the upper frets closer to the strings, resulting in a more even action up and down the board.

As Metal Mitch stated, don't think of the truss adjustment as an action setting tool. Yes, the action will change when you adjust this, but all you're trying to do here is get the right neck relief. It doesn't matter if your saddle action is high or low, and you don't need to lower the strings to get them buzzing to begin your adjustments. The relief will not change because of saddle height adjustments.
You'll eventually run across a bass that has an action that you just cannot fix by adjusting the truss and saddles alone. If you're thinking that you can even out the action at the higher frets by tightening the truss, this does not always hold true. Alot of that high action has to do with the fretboard's angle to the strings. You might end up with a properly adjusted neck relief, saddles as low as they can go without fret buzz at the lower frets, and still end up with an overly high action at the upper frets. A neck shim (if it's bolt-on) is in order here to cure this. Don't think that tightening the truss more is going to fix this. It won't. All you'll be doing is removing the PROPER RELIEF from the neck, causing more problems at the lower frets. Even if you somehow stumble across an action that feels good, notes on the fretboard just won't sound right. Some will sustain, others will not, and intonation will be even harder to set.

Remember that anytime you change tune or tension on the strings, you're also changing tension on the neck. So when you check relief, always make sure the strings are tune to the pitch you intend to play at. If you decide to downtune, well... you'll need a truss adjustment again.

Hope this helps..

Mag...

Magneto · #8 02-23-2005, 10:49 PM

I've been trying to think of the best way to describe this without going into a lengthy post.
Trussrod: For adjusting the small amount of forward bow (relief) that all basses must have for the strings to vibrate properly at the middle fret areas.
Saddles: For adjusting the actual string height.
Neck tilt adjustment or shim (bolt-on necks): For changing the angle at the neck pocket, which can bring the upper frets closer to the strings, resulting in a more even action up and down the board.

As Metal Mitch stated, don't think of the truss adjustment as an action setting tool. Yes, the action will change when you adjust this, but all you're trying to do here is get the right neck relief. It doesn't matter if your saddle action is high or low, and you don't need to lower the strings to get them buzzing to begin your adjustments. The relief will not change because of saddle height adjustments.
You'll eventually run across a bass that has an action that you just cannot fix by adjusting the truss and saddles alone. If you're thinking that you can even out the action at the higher frets by tightening the truss, this does not always hold true. Alot of that high action has to do with the fretboard's angle to the strings. You might end up with a properly adjusted neck relief, saddles as low as they can go without fret buzz at the lower frets, and still end up with an overly high action at the upper frets. A neck shim (if it's bolt-on) is in order here to cure this. Don't think that tightening the truss more is going to fix this. It won't. All you'll be doing is removing the PROPER RELIEF from the neck, causing more problems at the lower frets. Even if you somehow stumble across an action that feels good, notes on the fretboard just won't sound right. Some will sustain, others will not, and intonation will be even harder to set.
Ok, let's say you finally arrive at a good setup action. In the future, you'll only have to make a minor truss adjustment to keep that action, unless you change string type or gauges. You won't need to mess with the saddles. They are already set. If you found your action a bit too high one day, maybe due to temperature changes, all you would need to do is tighten the truss just a bit, checking the relief as you did in the beginning. The reverse holds true if the action went low.

Remember that anytime you change tune or tension on the strings, you're also changing tension on the neck. So when you check relief, always make sure the strings are tune to the pitch you intend to play at.

Hope this helps..

Mag...

sparktone · #9 02-23-2005, 11:38 PM

This is a somewhat related -- and probably very stupid -- question: If I'm going to remove a bolt-on neck and leave it off for a few weeks while I work on my bass, should I loosen the truss rod a few turns so develop a bow during the time it has no string tension?

Magneto · #10 02-24-2005, 12:01 AM

Quote:

Originally Posted by sparktone

This is a somewhat related -- and probably very stupid -- question: If I'm going to remove a bolt-on neck and leave it off for a few weeks while I work on my bass, should I loosen the truss rod a few turns so develop a bow during the time it has no string tension?

Yes. Definately..

Mag...

stingray5bbx · #11 02-24-2005, 01:02 PM

Someone PLEASE correct me if i'm wrong...

I was told for the MINIMUM amount of relief (all personal preference)... adj the rod so that :

When holding down 1st and last fret at the same time, there is credit card space in the middle of the neck between frets and strings.

This method takes the "saddle adjustment" out of the picture as you are pinning the string on the last fret.

Magneto · #12 02-25-2005, 07:30 AM

Quote:

Originally Posted by stingray5bbx

Someone PLEASE correct me if i'm wrong...

I was told for the MINIMUM amount of relief (all personal preference)... adj the rod so that :

When holding down 1st and last fret at the same time, there is credit card space in the middle of the neck between frets and strings.

This method takes the "saddle adjustment" out of the picture as you are pinning the string on the last fret.

I usually check the relief at the 8th or 9th fret. If a credit card's thickness works for your bass then use that. You could also get precise and use some feeler gauges. Once you know exactly how much relief works best for you, then you never have to guess again.
But honestly. If you hold down the string like you've described and you have just a bit of relief at the 8th fret, you're in good shape. If you have no clearance, or too much (very common), then it's time to adjust.
Although this might seem kinda technical or confusing to some at first, it's really very easy, and will keep your bass playing nicely. Once you follow these steps, you'll be able to keep your action just the way you want it by an occasional truss adjustment instead of constantly trying to raise/lower saddles because your action is changing. Those saddles don't move, but the neck will (it's made of wood)..

Mag....