Tuning up a Traditional Brekke Bridge

I recently acquired a mandolin with a traditional-style Brekke bridge. I went to adjust it to lower the action a bit (using the mini wrench that came with it) and could not get the saddle to go any lower. Hmmm. So I tried to raise the saddle a bit and it was quite difficult. I then loosened the strings, removed the bridge and discovered that the thumbwheels were impossible to turn by hand and quite difficult to turn even with the wrench.

I gradually worked the thumbwheels off by quarter turns off - on - off - on, loosened them very gradually and they now turn a lot easier but not easy enough. I guess the threads are a bit galled from having been over tightened against the end of the threads on the posts.

So. Question #1: Does anybody know what thread these are? They look like standard 4-40 threads to me. If so I will go down to the local Ace Hardware and get a tap and a die to clean them up. Or Question #1a: Is this a bad idea? What else would I do that would be better?

Question #2: The photo shows the bridge and saddle. A is the bass post and the thumbwheel is adjusted as far as it will go. My original desire was to lower the action a bit. I can see three ways to do it:
a) sand about an eighth of an inch off the top of the bridge where the thumbwheels seat themselves.
b) use the die I purchase for Q#1 to cut the threads further up each post. Post B shows how much unthreaded post I have to work with.
c) or a combination of a) and b).
I would remove an equivalent length from the end of each post to avoid having the post extend into the top of the mandolin.

Attachment 197708

So on Q#2, is there a problem is 2a or 2b or 2c? Or how would you do the job? Or, or, should I just buy a lowboy bridge and install it.

Many thanks for your thoughts!

I would think reaching out directly to Vern Brekke would a good solution.

Btw, Bruce Weber put one on my Absaroka and it also raised the action to ‘mostly unplayable’. I put the original Brekke bridge back on and haven’t looked back.

I had the same issue with my Weber Yellowstone.

1. I sanded down the elevated areas of the bridge's base where the holes for the posts are.
2. I sanded a small portion off the lower part of the saddle, though I wouldn'd recomment this if you get the desired effect after step 1.
3. I had to shorten the posts to match the overall smaller bridge. I was able to do this with 120 grit sandpaper since the metal part of the brekke bridge is made of brass (I think) which is relatively soft.

So yeah, a combination of sanding wood off the bridge and shortening the posts would certainly do the trick.
Just make sure you don't leave the posts to long, or else they will dig into the top of the mandolin. The holes for the posts go through the entire bridge base, as you surely will have noticed. The traditional brekke bridge works a little differently from "traditonal" traditional bridges in that regard.
Oh and don't cut the posts to short, or the stability of the whole bridge will suffer!

Forgot to mention:
I did in fact try to fit a cuberland lowboy bridge, but the arch of the mandolin's top was so much more pronounced than that of the bridge that was delivered to me, that by the time the bridge base had the desired arch, I had sanded off so much wood, that the posts came through the base (which is fine on a brekke bridge, but renders a normal bridge unusable).

Oh, another thing (sorry for dripfeeding :) )

Maybe by just exchanging the thumbwheels to some with a lower profile you could circumvent those more "invasive" interventions!
IMO you don't really need the "nut parts" of the thumbwheels and they take up quite an amount of space.

So a visit to your local hardware store could indeed be worthwhile (and no, I don't know the size of the threads, sorry)

Quote:

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Originally Posted by Willi Bahrenberg

Forgot to mention:
I did in fact try to fit a cuberland lowboy bridge, but the arch of the mandolin's top was so much more pronounced than that of the bridge that was delivered to me, that by the time the bridge base had the desired arch, I had sanded off so much wood, that the posts came through the base (which is fine on a brekke bridge, but renders a normal bridge unusable).

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On the traditional cumberland bridge the posts are not glued into base but can be unscrewed higher if you need some clearance from bottom or replaced by shorter ones (or cut shorter). The hex key access on these is typically underneath reachable through the small holes on the bottom of base or you can grip them with pliers with plastic jaws to unscrew.

To OP. have you tried lubing the hthreads a bit. I think they will be OK even if a bit tight (actually tightness prevents any possible rattless or tendency of nut to rock under pressure)

Had one of those bridges on a Gallatin. The base bottom on this particular one had been sanded very low to get adjustments to work. That's what I would advise to thin down as opposed to the top of the saddle.

As was mentioned above, contacting Mr. Brekke first would probably be the best course of action. FWIW, the adjustment nuts/wheels on mine moved quite easily with the tool. Even under tension. Good luck in getting it to work.

If the picture is of your bridge, it looks like you have a tall base. Weber also made a shorter base so you could sand down the top of the base extensions a bit (but as mentioned, as long as you also shorten the saddle screws so they have some clearance on the bottom of the base).

As for the screws binding, it looks as though you have one of the earlier bridges with a one piece brass bar and threaded posts under the saddle so either the posts or the thumbscrews could have been damaged.

The newer bridges had a brass bar, under the saddle, with standard black alloy 4-40 set screws screwed into the bar. A quick test to determine if it is the post threads that are bad or the thumbscrews is to pick up any 4-40 nut and try it out on the post threads.

Bruce Weber, Montana Lutherie, may be able to supply you with: new thumbscrews, a new bar and threaded posts and/or a shorter base.

(added: you should also check with Weber as it could be a warranty issue.)

Hope that this helps,

Vern Brekke
Bridger Products

Thanks all yall up above (and any subsequent advice)!
Adrian, thanks especially for suggestion to just lube the posts a bit - I gave each post a quick wipe with a birthday candle and both are now very smooth and easy to turn. I'm glad I don't have to "clean up" the threads.

Verne, this one is the older one-piece saddle-support-and-posts - all brass.

If I can get the threads to go all the way up the post, then I will definitely sand the bottom of the wood saddle so the brass bar is very slightly proud out of the slot it sits in. I'll probably also be sanding a bit off the top of the bridge base. Will let you know how things turn out

Subsequent: Total removal of the thumbwheels might be just right; I’ve done that one to avoid weakening the wood. Benefit is solid contact between the two parts. Also, the hex detail, which I also might think a needless embellishment, can be entirely removed if the knurled part is threaded and the material is decent brass. And, if your rethreading of those posts turns out to be difficult - and it might be if they’re part of another piece and the diameter there could be awkward, you can also gain some adjustment by counterboring the hex part so that it slips over.
In any event, if you have to shorten (non-removable) screws and don’t have something like a Dremel, use fine sandpaper or risk snapping them off.

TLDR: I did it and it plays a lot easier for me!

What I did:
1. Bought a 4-40 die for $5. Cut threads as far up the post as I could go. Helped a little but I didn't think it was enough. Counterbored a bit of the upper side of the thumbwheel. Helped a little more. But still it looked like I dropped only about a sixteenth of an inch in total (of total bridge and saddle height).
2. Sanded another sixteenth of an inch off the top of the bridge footer.
3. Cut about an eighth of an inch off each bridge post. That was enough to prevent poke through damage to mando top.
4. Cleaned everything up and reassembled everything.

I now have the action close to where I like it and can still go a bit lower. I have plenty of room to raise it, too. It really makes a difference. Glad I did it.

Hank, thanks for reporting back on what you ended up doing and how it worked out. Glad this is a success story!

I like the candle wax trick much better than putting oil or some such near the top of the mando. Given a choice I think I'd use a tiny dab of paste wax for that rather than wax - I still wouldn't want it on the finish, but it's good for bare wood and possibly less messy to get off the finish than candle wax if there were a "spill".

I use paraffin for lubrication as opposed to candle wax. Works well. Candles made out of beeswax will hold moisture, paraffin will not.