Bridge Design

[BigRedX]

This is a subject that I touched upon in my [url="http://basschat.co.uk/index.php?showtopic=21194"]Lace Helix review[/url]. Unnecessary complexity in bass bridge design.

For all it's faults the Fender bridge isn't actually too bad. The saddles move backwards and forwards for string intonation and go up and down to adjust the action. On some versions there is even limited string spacing adjustment. It's a good starting point and others have taken this and improved on it. There's the [url="http://www.leoquan.com/html/bass2details.html"]Badass II[/url], the [url="http://schaller-guitarparts.de/hp31505/3-D4.htm"]Schaller 3D[/url], the [url="http://www.hipshotproducts.com/cart.php?m=product_detail&p=118"]Hipshot A Style[/url] and the [url="http://www.abm-mueller.com/index2.html?bassbridges.html"]ABM 3D adjustable[/url]. Everything is screw or allen-key adjustable except for string spacing on the Badass where it's done using a file, but lets face it unless you are in the habit of swapping your bridges between different basses, string spacing is a set and forget feature.

What I've been seeing rather too much recently is bridges that look as though they have lots of adjustment possiblities, but when you come to use them actually don't, or are far too complex and fiddley to adjust.

I present exhibit A the bridge that prompted this post, the Lace Helix Bass Bridge:





Nice and solid looking and there looks like plenty of room for string height and intonation adjustment. However adjusting the two grub screws on the saddles doesn't actually appear to do anything... That's because the saddle is locked in place by another screw at the front of the bridge. It's not particularly easy to get to, but once it's slackened off the height adjustment screws actually work giving a total height adjustment of about 2mm! And that's the easy bit. To unlock the complete saddle assembly to adjust the intonation, there's yet another grub screw that needs to be slackened off. It's just visible in the second photo behind the black part of the saddle to the right of the string. The string has to be removed completely to access this and once it's loosened the whole bridge assembly slides around rather too freely in its channel. Getting the intonation right could involve 5-10 of these adjustments per string, completely loosening the string each time and there's always the possibility that the saddle assembly will shoot forwards or backwards when trying to make the final tiny adjustment meaning that you'll have to start all over again!

And if that wasn't bad enough here's exhibit B:





This is a Wilkinson bridge. That's right designed by Trevor Wilkinson someone you'd think new a thing or two about guitar design...

This time string height adjustment isn't too difficult. Looking at photo 1, the two allen screws at the top of each saddle and the one on the bottom right move the whole saddle assembly up and down. However to get maximum contact between the saddle and the rest of the bridge all three need to be adjusted the same. The other screw on the bottom left of the saddle locks it in place when adjusting the intonation. It works by pushing down on a ball bearing which in turn pushes sideways against the wall of the channel to hold the saddle assembly in place. It can be adjusted without removing the string, although you'll still need to slacken the string off to prevent the tension pushing the saddle forward. However don't remove the saddle assembly from the rest of the bridge because the ball bearing will drop out... Finally sting spacing is adjusted by loosening the screw visible in photo 2 at the front of the bridge and the sliding the notched string bearing left and right. This screw is of course almost impossible to get to with string in place.

I spent a good hour or so with each of these bridges just working out what all the different screws did and how they interacted with each other, and in the case of the Wilkinson bridge I pretty mach had to disassemble it to figure out how it worked.

What puzzles me is why these bridges exist? There are already plenty of designs that work much better than both of these and are far easier for the end user to adjust. In both cases its as though the creators of the bridge have tried to re-invent the wheel and not quite managed it. I've noticed a trend where intonation adjustments are no longer made using a screw with a spring on it it pulling the saddle back. Is there a sound reason for abandoning this method? Both the Lace Helix and Wilkinson bridges seem to be based on the Hipshot Type A, but without the user-friendliness. Have Hipshot been slinging lawsuits around Monster Cable style? That would be the only logically explanation I can see.

What do the rest of you think?

Edited June 22, 2008 by BigRedX

[neepheid]

Nothing's perfect. I love the Hipshot saddle design, but their bridges could do with some more intonation travel - like a Badass. I used an A style bridge on my first project bass and I ended up having only just enough travel available to intonate the E string. Perhaps I am culpable for my bridge positioning, but it gave me a bad moment. I've had to use a Badass V on my Zebrano Wideboy 5 as it's the only one with a baseplate big enough to cover the repairs I had to do to the body.

+1 on the string spacing being a set once and leave thing - I adjusted my Hipshot bridges once to suit the pickup pole pieces and I've never touched them since.

[ped]

Madness. I for one think the Schaller 3D is just perfect - does exactly what you need. I used to have a couple of bridges like the first example of yours. I had a real problem getting the string height low enough - even with the little metal inserts for the strings to break over at their lowest they were a good 5mm proud of the part which holds it in place. I ended up taking them all out and letting the strings run over the parts which hold the inserts instead. It sounded better and was much more adjustable. Stupid design. Used on many high end basses, too. Ritter, Marleaux and many others use these and I cannot understand why!

May I present one of my own?The Kahler bridge...



The problem being that the string passes over a grub screw that is slotted for the string. Height is adjustable by putting the grub screw up and down, but here is the problem. If your preferred height is half way through a turn (the thread isn't especially shallow) then you are forced to have it a bit too high or a bit too low, or, as I did, file down the string channel in the grub screw. Kind of annoying. However, once set they are great - fully adjustable for intonation and spacing. They look different too which is nice, but I would sacrifice that for a more functional adjustable bridge like the Schaller 3D with its sweet rolling string saddles.

Cheers
ped

[BigRedX]

The early Lightwave bridges (like the one on mine) suffer from the same problem as the Kahler, but they've managed to improve it by altering the saddle design so that instead of the whole saddle being the screw the string height is adjusted by an allen screw next to the saddle. I haven't actually seen this new improved design in anything other than diagrams in the current Lightwave users manual so I don't know how well it compares with the original. The Lightwave bridge could be included in the original rant as just about every single adjustment to it requires the string to be completely removed, which is a real pity because it's one of the few basses that using different strings can give a completely different sound to the bass and string experimentation can really pay off, unlike most other basses where there is generally one optimum string that suits your playing style and the sound you want, and once you've found it you are set.

Back to my original post, it makes me wonder why neither bass uses one of the existing bridges, either the Hipshot A or the ABM 3D would fit in terms of looks and surely the volumes being purchased mean they'd work out cheaper then going to the apparent expense of designing and then tooling up for a brand new design that at the end of the day doesn't work as well as previously existing ones?

Also there's the disturbing trend for bridges where the intonation is free set rather than the saddle being attached to a screw throught the bridge back plate. Is there a good reason in terms of sound for this? maybe one of the luthiers who post here would like to offer a suggestion?

[Lfalex v1.1]

+1 to Ped's Kahler 2400 nomination, but for a different reason!
I don't have an issue with the relative lack of height adjustment given by the bridge barrels, but the intonation grub screw is a real pain to get to, and it's tiny (2.5mm allen). Okay, set it and forget it, but it's difficult to do. A fact that is somewhat at odds with the design allowing you to change the action without tools, switch strings without having to thread them through anything, and the fact that it copes with the string angles converging towards the nut so well.

I may get a local engineering firm to knock me up some new barrels in a different material. The current ones are hollow steel, but I'm tempted to try aluminium, titanium, brass etc.

Another recommendation for this design;
If you sweat as much as I can do, remove the barrels and apply some Vaseline to the threads. It stops the steel barrels seizing in the Aluminium alloy body...

[Mr. Foxen]

I have one of those Wilkinson jobs, scored it on the bay as it looked suitably industrial. Lost a ball bearing, no its screwed. No idea how to sort it. Any suggestions?

[BigRedX]

You could try getting in touch with [url="http://www.jhs.co.uk/wilkinson.html"]JHS[/url] who are the UK distributor. However I notice that this particular bridge design is no longer listed.

[The Burpster]

[quote name='neepheid' post='224080' date='Jun 22 2008, 12:11 PM']Nothing's perfect. I love the Hipshot saddle design, but their bridges could do with some more intonation travel - like a Badass. I used an A style bridge on my first project bass and I ended up having only just enough travel available to intonate the E string.[/quote]


Neep,

I too was a littel frustrated at the Hippy A designs lack of adjustablity with the supplied set screws. I contacted teh tech dept at Hippy and they told me what size thread the screws are and I now have a selection of screws from a model engineering supplier....

Result?

I now have the entire range of the CNC rails in intonation adjustment......

Maybe you shouldnt have to go to that trouble but its very cool once you know!

[BigRedX]

Could you share with the rest of us the thread size and your source of suitable longer screws?

[BOD2]

Ladies and Gentlemen. I present to you.....the S-Tek Bridge.

[attachment=9994:S_Tek.jpg]

Nice design. very solid. Excellent contact with body. Through body option. Fairly easy to adjust.

BUT.....each string passes over a hardened steel "saddle" (the dark bit with the two allen key recesses). This saddle is locked into place with another allen bolt that lies horizontally under the strings at the front of the bridge. And if you don't ensure that bolt is tight then, when you take off a string, the saddle falls off.

Now imagine, at a gig, you break a string and the allen bolt isn't tight. Off goes the saddle. It's small, black, and you're on a dark stage with a black floor. Better hope you have a spare bass handy....

[The Burpster]

[quote name='BigRedX' post='224924' date='Jun 23 2008, 12:17 PM']Could you share with the rest of us the thread size and your source of suitable longer screws?[/quote]

Indeed sir I can ..... as you asked so nicley....!

it is a 4-40 thread. The std length in the Hippy A is 1" so if you want longer you need 1-1/4" and shorter 3/4".....


Supplier of all bolts you need....!


[url="http://www.modelfixings.co.uk/"]http://www.modelfixings.co.uk/[/url]

Enjoy....

[BigRedX]

BOD2 - That bridge seems to have exactly the same saddle adjustment as the Bridge on Lace. Considering how difficult it is to access the saddle height lock-down screw on the Lace where the saddles are near the front of their travel, I can image that it might be quite easy not the properly tighten them up when they're that far back in the bridge mounting...

Burpster - many thanks for the info and link, bookmarked!

[Kiwi]

Don't get me started on wilkinson bass bridges. Some of them are a step backwards in my experience. I had one where the break angle was so poor that the saddles actually lifted off the base plate!!

[BOD2]

[quote name='BigRedX' post='226122' date='Jun 24 2008, 07:16 PM']BOD2 - That bridge seems to have exactly the same saddle adjustment as the Bridge on Lace. Considering how difficult it is to access the saddle height lock-down screw on the Lace where the saddles are near the front of their travel, I can image that it might be quite easy not the properly tighten them up when they're that far back in the bridge mounting...[/quote]

You're right - they look identical. I hadn't noticed that. Well that's something else you need to watch out for on the Lace - losing the saddles !