Thread: Truss Rod setup help needed

The truss rod(s) aren't supposed to move the neck , but rather counteract the pull of the strings so you don't get an excessive forward bow from the string pulling on the neck. There should be some forward bow when properly setup otherwise the strings will tend to rattle against the frets. If you press the string down at the first and last fret, there should be some clearance between the string and the frets in the middle of the fingerboard. What I do is snug up the truss rod when the strings are untensioned, and then tune the strings to pitch and see how much forward bow there is. Always slack off the string tension before re-adjusting the truss rod.

Originally Posted by byacey

The truss rod(s) aren't supposed to move the neck , but rather counteract the pull of the strings so you don't get an excessive forward bow from the string pulling on the neck. There should be some forward bow when properly setup otherwise the strings will tend to rattle against the frets. If you press the string down at the first and last fret, there should be some clearance between the string and the frets in the middle of the fingerboard. What I do is snug up the truss rod when the strings are untensioned, and then tune the strings to pitch and see how much forward bow there is. Always slack off the string tension before re-adjusting the truss rod.

There is some forward bow, but too much. I have been tightening the truss rods with the strings at full tension, so I'll try slacking it all off and going form there - thanks. After you have adjusted the truss rod do you wait any time before tightening the strings or can you do it straight away? Also, given that I currently have lots of tension on the truss rods and the strings to pitch - so I just loosen off the strings and then re-tune them and see what happens, or do I loosen off the rods, and then loosen off the strings (basically reverse order to what I have done so far) and then start again?

Thanks

Peter

I would start from scratch. Loosen the string tension completely, and loosen the truss rod completely, and then tension up the truss rod. It helps sometimes to bow the neck back while tightening the truss rod as this takes tension off the rod momentarily while you tighten the rod. Then tune the strings to pitch and check the action. If the strings are rattling when playing around the 5th fret, you need to loosen up the truss rod slightly to allow a little more forward bow. Again, I would release string tension before making each and every adjustment on the truss rod.

Forward bow setting is dependent on the style of playing. The more aggresive a musician is, the more clearance you need to keep the strings from rattling.

What is the neck made from? When I built my bass I almost didn't even need a truss rod as I built the whole instrument from Cocobolo, including the neck.

Originally Posted by byacey

I would start from scratch. Loosen the string tension completely, and loosen the truss rod completely, and then tension up the truss rod. It helps sometimes to bow the neck back while tightening the truss rod as this takes tension off the rod momentarily while you tighten the rod. Then tune the strings to pitch and check the action. If the strings are rattling when playing around the 5th fret, you need to loosen up the truss rod slightly to allow a little more forward bow. Again, I would release string tension before making each and every adjustment on the truss rod.

Forward bow setting is dependent on the style of playing. The more aggresive a musician is, the more clearance you need to keep the strings from rattling.

What is the neck made from? When I built my bass I almost didn't even need a truss rod as I built the whole instrument from Cocobolo, including the neck.

Thanks for that - I'll give it a go. Wish me luck!!. This is a neck through. Neck is Maple and walnut laminations - 3 maple and 2 walnut. It has been the longest project - my son is 8 and he wasn't around when I started. I am so looking forward to havin ghtis thing finished...

Peter

sounds like you made the rods yourself?
if thats the case then theres your problem...
the old bent rod and brass stock wont cut it for a bass with two rods, you want something a bit more heavy duty....

Originally Posted by Andrew_B

sounds like you made the rods yourself?
if thats the case then theres your problem...
the old bent rod and brass stock wont cut it for a bass with two rods, you want something a bit more heavy duty....

I bought the rods from Gilet Guitars. I explained the purpose of them when I bought them, so hopefully they will be OK. If not I will be seriously annoyed. I guess that would mean taking off the fretboard again and extracting the rods, and filling the channels and installing new rods. Obviously I am keen to avoid that

Peter

gilet sell the rods in a diy form yea?

havnt been to their site for a while....

but from memory they sell them by the piece

they are the bent rod with a brass block at each end yea?

Originally Posted by Andrew_B

the old bent rod and brass stock wont cut it for a bass with two rods, you want something a bit more heavy duty....

Well, not really. With a well made neck and truss rod(s), a single one of these rods will be good for 5 and even a 6 string bass, they can handle it.

But I am curious as to what type of rod was in there originally.

Originally Posted by Andrew_B

gilet sell the rods in a diy form yea?

havnt been to their site for a while....

but from memory they sell them by the piece

they are the bent rod with a brass block at each end yea?

Yeah, they sell it as pieces - the rod, the block and the nut. The rod is a U shape but needs more flattening, then you have to thread it, insert in the block, attach the nut and then bind it all with tape.

There was no rod in the instrument - this is a scratch build, so these rods are the originals.

Last night I did what byacey suggested and took the tension off the strings and the rods. There was quite a pronounced forward bow on the neck - where it started out at dead straight. I guess the tension of having strings on it with no back pressure from the rods (or not enough anyway) has left a permanent warp on the neck. I then used the truss rods to straighten this out. Some time I will loosen this tension off again, and hope that the reverse has happened, and that it is permanently straight again. Whatever happens I wil use the "bend the neck and then adjust the rods" technique and see how I go.

Peter

Some heat can be used to help straighten the neck. You have to apply heat for a long period of time to thoroughly penetrate to the core of the neck, but not too hot as to scorch the wood.

I got it straightened OK with the tension on the rods - took the tension back off and the neck stayed straight. Now just to get it adjusted properly. I have just had an epiphany, and I bet I'm right. The instructions specified for the thread to be BSF (well they didn't, they specified threads per inch, but it turns out it was BSF). Anyway, I couldn't fins a die with the correct pitch, so I ditched the allan nuts that cam with it, and used standard BSW nuts and BSW die to cut the thread. I have just realised that may have been a mistake, as I guess the finer thread would give more leverage to the whole affair. That's probably one reason why it becomes very hard to turn after only 1/2 - 3/4 turn. I guess next time I'll use the finer thread pitch - I now have managed to track down the correct die (at Salamanca markets while I was in Tassie on holidays of all things). For now, with the idea of physically bending the neck and then tightening the rods to suit I guess I'll get the correct setting on it eventually. And I've learned a few things.

Peter