Mile high action... actually, make that two miles

SMILEYSIXX · #1 07-11-2011, 07:28 PM

So I shimmed my neck to tilt it forward a tad (at least I thought it would only be a tad), but my strings sit about 1/4" above my fretboard. Now, I am a high action kind of guy, but this is the highest I've ever played. I like it, but I just wanna make sure there isn't anything wrong with this situation. I intonated it and it sounds great, but this high of action seems... abnormal?

**FunkyMcNasty** · #2 07-11-2011, 07:33 PM

"mile high action"......I'd like to see that

allexcosta · #3 07-11-2011, 08:54 PM

Quote:

Originally Posted by FunkyMcNasty

"mile high action"......I'd like to see that

darkstorm · #4 07-11-2011, 09:55 PM

Shims normally go in the back of the neck pocket so its up against the rear wall. This causes neck to get the needed little bit of rearward tilt for better low action. Sounds like you put the shim at the front of the neck pocket instead. Causeing higher action. 1/4 inch action is rediculous imo and Id never concider a bass set up that way myself.

allexcosta · #5 07-12-2011, 04:38 AM

Very high action increases the pull of the strings and eventually can damage the neck.

Simple test:

Grab a flexible metal ruler like this one:

Attach some cord to that hole and press the other side of the ruler against the edge of a table, as if the ruler was the neck of your bass, the table was the body, and the cord was a string.

Simulate a low action and try to bend the ruler. You'll need a lot of strength pull to do it. Now rise the action, changing the angle and do the same thing. You'll need to apply A LOT less strength to bend the ruler...

It's physics...

staindbass · #6 07-12-2011, 04:45 AM

yup, like darkstorm said you have the shim in the wrong place. slide it toward the bridge all the way. a 1/4 inch? the shim may be too thick. some people use pieces of buisness card.

mongo2 · #7 07-12-2011, 06:22 AM

Quote:

Originally Posted by allexcosta

Very high action increases the pull of the strings and eventually can damage the neck.

String tension at pitch is the same no matter what the action is like.

JKos · #8 07-12-2011, 06:39 AM

> String tension at pitch is the same no matter what the action is like.

But the force trying to bend the neck increases as the action increases.

- John

allexcosta · #9 07-12-2011, 06:53 AM

Quote:

Originally Posted by mongo2

String tension at pitch is the same no matter what the action is like.

What John said...

The force changes with different angles. "Vector forces"

john grey · #10 07-12-2011, 07:47 AM

Shimming a neck is not something that should be undertaken lightly. I have also seen problems with shimming. Please remove the shim and take the bass to a qualified individual who has experience in that and other issues. It will save frustration in the short term and possible damage in the long run.

SMILEYSIXX · #11 07-12-2011, 08:47 AM

I'm failing to see how higher action bends the neck more. If the strings pull straight down on the neck or at a slight angle, the pressure would still be the same, no?

Slowgypsy · #12 07-12-2011, 08:53 AM

Quote:

Originally Posted by SMILEYSIXX

So I shimmed my neck to tilt it forward a tad (at least I thought it would only be a tad), but my strings sit about 1/4" above my fretboard. Now, I am a high action kind of guy, but this is the highest I've ever played. I like it, but I just wanna make sure there isn't anything wrong with this situation. I intonated it and it sounds great, but this high of action seems... abnormal?

Just getting back to the original post. What set of conditions led you to believe that the neck needed shimming?

Bassamatic · #13 07-12-2011, 08:57 AM

The higher the angle, the more force pulling the neck up. When the action is low, the force is nearly parallel to the neck. As the action increases, more of the tension is converted to pulling the head UP.

Attach a rope to a small tree, along the ground. Pull - the tree doesn't move. Attach it higher up - the tree bends.

MikeBass · #14 07-12-2011, 08:58 AM

Quote:

Originally Posted by allexcosta

Very high action increases the pull of the strings and eventually can damage the neck.
Simple test:

Grab a flexible metal ruler like this one:

Attach some cord to that hole and press the other side of the ruler against the edge of a table, as if the ruler was the neck of your bass, the table was the body, and the cord was a string.

Simulate a low action and try to bend the ruler. You'll need a lot of strength pull to do it. Now rise the action, changing the angle and do the same thing. You'll need to apply A LOT less strength to bend the ruler...

It's physics...

Umm....no.......

If you are talking distances and angles of significiant degrees, maybe.
But this isn't the case with a bass neck and the angle of the string in relation to the plane of the neck.

Put the string at a 30deg angle in relation to the neck (X plane) and yes, you will see significant forces/changes in forces as you move from the nut towards the bridge.

I figured 1/4" at the 12th fret with a 1/16" string height at the nut.........0.632deg from X (the plane of the neck)
Give me where that 1/4" is measured from and I'll give you better angles.
Also give me the manufacturer of the string, I'll look up the tension when tuned to pitch, I'll model up a neck in maple with the correct material properties (but without a truss rod) and I'll process the FMA and give you numbers.

My point is, you would have to jack up the action so high to do any damage and given the design of a neck outright, unless the materials used are suspect, it's designed to withstand high action.

dmusic148 · #15 07-12-2011, 09:05 AM

Quote:

Originally Posted by MikeBass

Umm....no.......

If you are talking distances and angles of significiant degrees, maybe.
But this isn't the case with a bass neck and the angle of the string in relation to the plane of the neck.

True. If you could raise the action to, say, 6 or 8 inches off the fingerboard, you can see how this would apply a significant bending force to the neck. But with the small angles we are talking about, the truss rod will handle it without problems.

allexcosta · #16 07-12-2011, 09:10 AM

Quote:

Originally Posted by MikeBass

My point is, you would have to jack up the action so high to do any damage and given the design of a neck outright, unless the materials used are suspect, it's designed to withstand high action.

I respectfully disagree...

This thread is not just about high action, but abnormally high action...

In real world I have seen well built basses develop a bow after years of being left in the closet with strings in tune and very high action...

dmusic148 · #17 07-12-2011, 09:14 AM

Quote:

Originally Posted by allexcosta

I respectfully disagree...

This thread is not just about high action, but abnormally high action...

In real world I have seen well built basses develop a bow after years of being left in the closet with strings in tune and very high action...

Betcha a million bucks that the bow caused the abnormally high action, not the other way around.....seen it lots of times myself....betcha......of course there's no way for either of us to prove it so.....I'll leave now.

MikeBass · #18 07-12-2011, 09:40 AM

Quote:

Originally Posted by allexcosta

I respectfully disagree...

This thread is not just about high action, but abnormally high action...

In real world I have seen well built basses develop a bow after years of being left in the closet with strings in tune and very high action...

You're not really proving a point here.
That could and has happened with basses with low action as well.
I've seen it too. And with a properly functioning truss rod, that bow should be able to be removed.
By being left untouched in a closet with zero adjustments- sure the neck will move.
But to make a sweeping statement that high action will "damage" a neck....no. I respectfully disagree as well.
It may need more attention or adjustments maybe. but damage......
And to counter that, for every one that you may have seen with issues like that, how many have you seen that have none?
2:1, 3:1 more?????
I've come across more decades old basses belonging to players who have stupid high action and there are no issues to be seen or mentioned.

i had a neck-thru Warwick Thumb fretless 5 (with the wenge neck) and it developed a neck problem.
And I have kinda nutty low action.
See my point?
Orchestra instruments of hundreds of years old, which by comparison have significantly higher action than an electric bass will need attention, but never to the point because the set-up "damaged" the neck.
I have friends who are professional string players, and I don't ever recall them mentioning anything about damage to they're instruments from the set-up.

aborgman · #19 07-12-2011, 09:40 AM

Quote:

Originally Posted by Gio S

The higher the angle, the more force pulling the neck up. When the action is low, the force is nearly parallel to the neck. As the action increases, more of the tension is converted to pulling the head UP.

Yes...

and with a shim (and only an angled shim) we're talking about changing the angle at most a tiny bit, well less than a degree.

So we go from 100% parallel pull to 99.999% parallel pull an .0001% upward pull.

MikeBass · #20 07-12-2011, 09:49 AM

Quote:

Originally Posted by aborgman

Yes...

and with a shim (and only an angled shim) we're talking about changing the angle at most a tiny bit, well less than a degree.

So we go from 100% parallel pull to 99.999% parallel pull an .0001% upward pull.

That's my point.