Getting the Facts about Ski Jumps

[sissy kathy]

What is the proper way to alleviate a bass with the dreaded ski jump around 12th fret and beyond? Some luthiers will say it’ll just need fretwork, but will anything help or is the bass a waste?

Much depends on how stable the neck is, and just how bad the ski jump is. An old neck with a minor ski jump can probably get away with a fret dressing. On the other hand, a neck that is only a year or two old with a severe ski jump probably needs to be replaced. So there's no pat answer.

 

[/\/\3phist0]

What is the proper way to alleviate a bass with the dreaded ski jump around 12th fret and beyond? Some luthiers will say it’ll just need fretwork, but will anything help or is the bass a waste?

Perhaps only the neck (at WORST ) would need replacement.

 

[melodiaopus]

Much depends on how stable the neck is, and just how bad the ski jump is. An old neck with a minor ski jump can probably get away with a fret dressing. On the other hand, a neck that is only a year or two old with a severe ski jump probably needs to be replaced. So there's no pat answer.

The bass is built in 2018. Moollon P4 Classic

 

[Drucifer]

Wood is gonna do what it wants, I've found that out the hard way. If you really want a neck that absolutely will not move in response to any normal range of temperature or humidity..... Get a Steinberger.

Or a Zon, or a Modulus, or a Travis Bean, or any bass with a neck made of something other than wood.

 

[Gilmourisgod]

Or a Zon, or a Modulus, or a Travis Bean, or any bass with a neck made of something other than wood.

A guy I knew in college had one of the Travis Bean basses with the "T" cutout in the headstock, all aluminum neck, and that thing WOULD NOT stay in tune. The heat from your hand was enough to make it move. There was a later version with wood inserts, I always assumed they added them for that reason, or maybe just so it didn't feel so cold.

 

[Turnaround]

What is the proper way to alleviate a bass with the dreaded ski jump around 12th fret and beyond? Some luthiers will say it’ll just need fretwork, but will anything help or is the bass a waste?

If you know for a fact thqt there's a ski jump, you may be able to work around it. Try this technique and see if it works for you - if it doesn't you will either need to have the fretboard and frets re-levelled or replace the neck.

Start by deciding how for up the neck you want to play. Pick the highest note you want to be able to play on each string. That will be your "top" fret.

1. Whatever your choice for "top" fret is, fret the string one semi-tone lower (next fret toward the nut). Adjust the bridge until it plays cleanly (or with the degree of buzz you find acceptable). Check the next two or three frets down and ensure they play well. If not raise the bridge a tiny bit until your top two or three "top" frets play well.
2. Adjust the truss rod until nearly flat. Play notes near the first fet - they will likely buzz.
3. Add a little relief by loosening the truss rod and test it again near the first fret. Keep on adjusting the truss rod until you get it playing the way you want at the first fret. DO NOT ADJUST THE BRIDGE FROM THE WAY YOU SET IT IN STEP 1.

You will end up with the best compromise possible given the condition of the neck. If it's unacceptable you have 3 choices:

1. Chose a lower "top fret" and repeat the process starting at step 1. You might be able to get to the point where the compromises you are making are good enough. If not proceed to option 2.
2. If the ski jump isn't too bad, you might be able to get the action to an acceptable position by levelling the frets end-to-end of the fretboard. Sometimes that will leave the upper frets too low to function properly, in which case proceed to the next option.
3. Remove the frets in the upper region and re-level the fretboard, install new frets and level them. But sometimes there's not enough thickness on the fretboard to level it flat. If so - next option
4. Heat treat the neck to flatten out the ski jump. But before you do consider that it may not work. Even if it does it may not stay flat. The tension of the strings caused the ski jump in the first place and unless you do something to reinforce the neck the string tension will bend the neck again. So you should look at reinforcing the neck as well as heat treating. This is starting to get expensive so you might rather consider the next option.
5. Replace the neck. The neck is the most critical part of the entire instrument, so don't cheap out.

Good luck.

 

[Bruce Johnson]

What is the proper way to alleviate a bass with the dreaded ski jump around 12th fret and beyond? Some luthiers will say it’ll just need fretwork, but will anything help or is the bass a waste?

Have you read through this thread? That's exactly the subject: What causes Ski Jumps and how to repair them. It's all in here in the previous pages. We've spent years writing it, just for you!

 

[melodiaopus]

Have you read through this thread? That's exactly the subject: What causes Ski Jumps and how to repair them. It's all in here in the previous pages. We've spent years writing it, just for you!

Yeah, read about 2-3 pages from back in 2014 but didn't get any clear idea on what it might take in the event of this happening. It's rather extensive 10 year + thread so thought it would be quicker to just ask.

 

[melodiaopus]

If you know for a fact thqt there's a ski jump, you may be able to work around it. Try this technique and see if it works for you - if it doesn't you will either need to have the fretboard and frets re-levelled or replace the neck.

Start by deciding how for up the neck you want to play. Pick the highest note you want to be able to play on each string. That will be your "top" fret.

1. Whatever your choice for "top" fret is, fret the string one semi-tone lower (next fret toward the nut). Adjust the bridge until it plays cleanly (or with the degree of buzz you find acceptable). Check the next two or three frets down and ensure they play well. If not raise the bridge a tiny bit until your top two or three "top" frets play well.
2. Adjust the truss rod until nearly flat. Play notes near the first fet - they will likely buzz.
3. Add a little relief by loosening the truss rod and test it again near the first fret. Keep on adjusting the truss rod until you get it playing the way you want at the first fret. DO NOT ADJUST THE BRIDGE FROM THE WAY YOU SET IT IN STEP 1.

You will end up with the best compromise possible given the condition of the neck. If it's unacceptable you have 3 choices:

1. Chose a lower "top fret" and repeat the process starting at step 1. You might be able to get to the point where the compromises you are making are good enough. If not proceed to option 2.
2. If the ski jump isn't too bad, you might be able to get the action to an acceptable position by levelling the frets end-to-end of the fretboard. Sometimes that will leave the upper frets too low to function properly, in which case proceed to the next option.
3. Remove the frets in the upper region and re-level the fretboard, install new frets and level them. But sometimes there's not enough thickness on the fretboard to level it flat. If so - next option
4. Heat treat the neck to flatten out the ski jump. But before you do consider that it may not work. Even if it does it may not stay flat. The tension of the strings caused the ski jump in the first place and unless you do something to reinforce the neck the string tension will bend the neck again. So you should look at reinforcing the neck as well as heat treating. This is starting to get expensive so you might rather consider the next option.
5. Replace the neck. The neck is the most critical part of the entire instrument, so don't cheap out.

Good luck.

Appreciate this! I am not a luthier, so just wanted to gauge how deep this is to go for getting the neck rectified and whether or not its worth the investment for purchasing a bass with a possible ski jump neck. One luthier that the seller mentioned was that doing some fret leveling where the most buzz is occurring would help upon their observation. But as the thread mentioned in the past that it's basically just a bandaid and the neck could continue to bend etc.

 

[Bruce Johnson]

Appreciate this! I am not a luthier, so just wanted to gauge how deep this is to go for getting the neck rectified and whether or not its worth the investment for purchasing a bass with a possible ski jump neck. One luthier that the seller mentioned was that doing some fret leveling where the most buzz is occurring would help upon their observation. But as the thread mentioned in the past that it's basically just a bandaid and the neck could continue to bend etc.

The quick condensed answer is: From here, we can't tell you for sure how difficult that bass will be to fix, or whether the fix will hold long term. If the bass is more than 10 years old, and the kink (ski jump) isn't too bad, then you may be able to fix it with the setup routine that Richard described above, or a simple fret leveling. And it may be fine for decades.

But if it's a younger bass and the kink is pretty bad, then the repair is going to involve some expensive surgery. And that repair should include some kind of embedded stiffener to make sure the neck doesn't continue bending over the years.

 

[Fender_Bender]

Appreciate this! I am not a luthier, so just wanted to gauge how deep this is to go for getting the neck rectified and whether or not its worth the investment for purchasing a bass with a possible ski jump neck. One luthier that the seller mentioned was that doing some fret leveling where the most buzz is occurring would help upon their observation. But as the thread mentioned in the past that it's basically just a bandaid and the neck could continue to bend etc.

You can always strap it on , grab the headstock, hold the body down by the bridge and gauge how easy it is to flex the neck back against the string pull. Compare it to other basses to get a rough estimate on how stiff the neck is relatively speaking. If it’s at least average in stiffness I think you’ll be able to get it where you want. If it flexes like spaghetti, not so much.

 

[TonH]

I have a collection of six Precision Elite basses from the 80s. Three of them have a maple neck/fretboard, and three have a maple neck and rosewood fretboard.

The necks of those Elite basses are thin back to front.

Over the past few days, I've re-stringed and did a setup on all of them.

I noticed that I could set the action lower on the all-maple necks than on the maple/rosewood necks.

Buzzing from fret 14/15 to 20 on the maple/rosewood necks.

Are necks with a rosewood fretboard more susceptible to ski jumps?

 

[sissy kathy]

I have a collection of six Precision Elite basses from the 80s. Three of them have a maple neck/fretboard, and three have a maple neck and rosewood fretboard.

The necks of those Elite basses are thin back to front.

Over the past few days, I've re-stringed and did a setup on all of them.

I noticed that I could set the action lower on the all-maple necks than on the maple/rosewood necks.

Buzzing from fret 14/15 to 20 on the maple/rosewood necks.

Are necks with a rosewood fretboard more susceptible to ski jumps?

Not really, stress formed during the tree's growth, string gauge and the thickness have more to do with it than the type of wood, within reason anyway. You can expect any fast growing wood to flex more than a slow growth wood, but that may have more to do with keeping the neck flat rather than a 12th freet kink.

 

[walterw]

some useful new anecdotes about shims!

user "timtam" over on TGP has some interesting links from folks who have done some testing, including plek scans and just clamping up a neck with a shim and observing the results long term

upshot is those shims make for more distortion than we may realize!

The case against Fender's Micro-Tilt - Strange Guitarworks

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...

www.strangeguitarworks.com

and an excerpt from the gerry hayes newsletter (haze guitars)

Hey there
I’ve been meaning to get back to this for a while but haven’t gotten around to it. You may remember that, from time to time, I’ve discussed the view that shimming a neck with a short/partial shim (or with Fender’s Micro Tilt adjustment) is a bad idea. I’ve said that it can cause deformation in this part of the neck and will produce an end-of-neck ski-jump causing fret buzz and related pain-in-the-ass setup problems.
Whenever I’ve talked about this, I’ve gotten some push-back. Most of it boils down to, “There’s no way a shim can deform a big, thick hunk of strong wood like a guitar neck. It must have been <insert special pleading of choice here>.” And, while I’d like to have replied with, “Yeah? Well, shut up!”, I generally politely responded by saying that all of my experience told me it could but that I had to admit that wasn’t the most scientific answer.
So, I decided to do an experiment.
So, a few years back, I bought a spanking new guitar neck. I checked it was straight and also triple-checked the back of the neck heel to ensure it was flat and even where it was supposed to be flat and even.
Then, I made a surrogate body from a hunk of wood I had lying about before screwing the neck to its new body with a damn popsicle stick as a shim. I strung up this ‘guitar’ to pitch and put it in a quiet spot in my workshop to wait.
And wait I did. I mostly forgot about this experiment. Now and then, it’d occur to me but, with plenty of other stuff to get on with, my "guitar" was shimmed and strung to pitch for more than three years before I returned to it.
So, was there any effect noted?
Of course there was. I’m writing about it, aren’t I?

That’s the rear of the neck. What had been a flat neck heel now has a clear ramp-off at the end.
And…

If you look closely at this photo, you’ll see that you can actually discern the deformation at the fingerboard side. That straight edge along the edge of the fingerboard (in line with the fret ends) shows a small but noticeable kick up. I can read this with a straight-edge and relief gauge too. The deformation at the back is enough to carry through to the fingerboard and the fret-plane. And you better believe that a fret height difference you can see is absolutely going to cause fret buzz you can hear.
To be clear here, I've seen this (and worse) before and I've even posted similar images before. What was different in this case was that I had a known starting point. I couldn't be 100% sure if all of these that I'd seen before hadn't had some earlier deformation or had other event occur that could have caused the problem. Here, I had a straight neck and heel, no wear and tear, no use, stored in a humidity-controlled environment that doesn't see any extremes of temperature. Added to the instances I'd already seen this experiment was more than enough for me
But then I got a little extra support…

A little extra science​

In a stroke of luck, as I began blowing the dust off this experiment, a reader (thanks Keith) emailed to pass on an article he’d come across.
Benjamin Strange of Strange Guitarworks wrote about his own experiments playing with Fender’s Micro-Tilt and partial shims. It makes for very interesting reading. Check it out at The case against Fender’s Micro-Tilt.
To summarise: Benjamin, with the very handy benefit of a PLEK machine, fretted and levelled a guitar (a Tele in this case). He scanned it afterwards in the PLEK to ensure it was in good shape and it certainly was — all frets within a few thousandths of a millimetre.
He slackened the strings and neck screws before engaging the Micro-Tilt adjustment. After stringing back to pitch he scanned again and saw a measurable deformation at the end of the neck. He also experienced some fret buzz in that area.
Benjamin repeated the experiment, this time with a short/partial shim instead of the Micro-Tilt. His scan showed that this was even worse — both in terms of measurement and fret-buzz. Interestingly, the deformation from the Micro-Tilt was centred around the D and G strings in the middle of the fingerboard whereas the shim caused it across the fingerboard. This makes sense as the Micro-Tilt applies its pressure to one point in the centre of the neck heel.

I’m calling it!​

That’s it for me and the short-shimmers. Along with my experience, my own empirical evidence for this, my (albeit small sample-size) experiment, and the impressive PLEK information provided in Benjamin’s post, I’m calling it.
For anyone who firmly believes that a short shim couldn’t possibly cause a neck deformation, that’s awesome… You do you. I don’t see any real benefit in arguing this point any more. If you have a list of things you’ve found problematic in my experiment or in the information provided at Strange Guitarworks, feel free to write them on a postcard and mail to Bureau of Special Pleadings, Dead Letter Avenue, Null Island.

The last word​

If you need to shim your neck, ignore the Micro-Tilt and forget about partial shims. You can make an angled, wedge-shaped shim if you have the patience but, realistically, it’s easy to buy a full-pocket, angled shim now. Stew Mac has been selling them for a while. Yes, you can bleat and moan that ten bucks is too much to charge for a little piece of wood but that’s considerably cheaper than the fret level or refret that may follow poor shimming choices. Word on the street is that you can get these shims even cheaper on Amazon these days (I haven’t used any sourced there so caveat emptor).
My experimental neck has taken on its deformation as a permanent feature. It doesn’t go away. I can just take some time to level the frets but most players will need to fork out for fret work. Spend a few bucks and get a proper neck shim. Or make one if you’re bored and have some time to kill.

Just don’t use short shims and Micro-Tilts.
Done!
Dusted!
Mic drop!
Cheers. Talk soon.

Gerry

 

[Turnaround]

I'm keeping an open mind about this. Gerry's experience differs from mine. I have been trying to induce a heel lift with a shim - it's been 5 years now with the shim in place and the neck under string tension, and there is no deformation yet. But mine is only a sample of one.

 

[walterw]

I'm keeping an open mind about this. Gerry's experience differs from mine. I have been trying to induce a heel lift with a shim - it's been 5 years now with the shim in place and the neck under string tension, and there is no deformation yet. But mine is only a sample of one.

i remembered that, which is why i was struck by his result! i have to wonder if jerry is tightening to anything beyond the normal force of a fender-style neck screw

 

[Turnaround]

I don't know if it makes a difference, but the heel of a typical bolt-on bass neck has 43% more mass than a a typical bolt-on guitar neck. All my testing was done with a bass neck, and I believe the quoted tests wew done with guitar necks. That might account for the differences in outcome.

 

[Matt Liebenau]

I was going to mention he says in the test he used a popsicle stick for a shim which is rather thick, assuming it’s not hyperbole, compared to a playing card or piece of veneer. The other test he references seems like they may have used a thinner material or slight adjustment of the micro-tilt but it’s hard to tell just from what’s written there. I didn’t check out the link.

 

[Turnaround]

I was going to mention he says in the test he used a popsicle stick for a shim which is rather thick, assuming it’s not hyperbole, compared to a playing card or piece of veneer. The other test he references seems like they may have used a thinner material or slight adjustment of the micro-tilt but it’s hard to tell just from what’s written there. I didn’t check out the link.

One thing I find odd about the photos is that in the pic with the rule on the back of the heel you see a gap at the end of around 1mm. But when looking at the topside photo the deviation is much smaller. Without compression forces I don't see how this could happen.

I also find the Strange experiment strange (Strange did the Plek test). With a micro tilt, the tilt point is between the innermost screws, so there is no longitudinal bending force provided by the inner screws at that point. All bending force must come from the outermost screws and they won't have much leverage given that they are so close to the pocket's outer end (the fulcrum) end so far from the point they are acting against. I can see that a very narrow shim as shown in one of the photos could provide more force since both inner and outer screws are acting against the lift of the shim, and this is borne out by the measurements taken by the Plek. BTW I would never use a shim that narrow - I would always use a shim that reaches the inner screw holes, providing support right at those screws.

I really don't know what to make of it all, except to surmise that the difference of size between a bass neck heel and one from a guitar may be a factor in the outcome of the tests.

 

[djmay]

I have 2 fretless (1 bolt-on and 1 neckthrough) and 2 fretted (1 bolt-on and 1 neckthrough). I discovered this wonderful thread after using the @Bruce Johnson method for flattening the fretless string paths. There was a limit to how flat they could be due to neck kink. I have used @Turnaround suggestions for saddle adjustments to compensate as best as possible.

The same works for the fretted bolt-on. All instruments are between 9 and 30 years old.

I think if I ever buy another bass, it will be at least 20 years old so that I can evaluate the neck condition. Thank you @Turnaround for starting this thread.