I was tempted to write this under another thread http://www.banjohangout.org/topic/236462 but decided it was probably best in its own thread.
I'm most defintely a newbie as far as music theory or musicianship goes. I've never played any instrument until a year ago, when I bought a Deering Goodtime.
Yesterday I picked up 4 of Steve Davis's bridges from the PO.
Like many neophytes, I looked upon changing a bridge for the first time as a bit of a challenge. Happily, I can report it is relatively simple.
I did my BHO and youtube research first and then tackled the task like this:
I applied graphite/pencil lead to all bridge slots.
I backed off (flattened) all 5 strings about 7-8 half turns. I chose to do this by only turning each peg twice each time, working my way around in a pattern (4th, 1st, 2nd, 5th, 3rd), rather than backing off 1 string all the way before moving on to the next. (Like how we all tighten the nuts when putting our car wheels back on. It may be completely unnecessary to loosen strings like this, but it suits my thinking).
Once the strings were loose enough to slip my (slender) left hand under the strings near where the neck joins, I gently lifted the strings a tad, moved the old bridge towards the neck, tipped it forward and then slipped it out sideways. I then did the reverse, slipping the new (facedown) bridge in under the strings, moved it back toward the tailpiece, stood it up the right way, slid the strings into their respective bridge slots, and then moved the bridge pretty close to its final position. I made a point of ensuring the centre of the bridge was in line with the centre axis of the banjo neck, so I wouldn't need to move it sideways once the strings were at full tension. The easiest way for me to do this was ensure the 1st and 4th strings lined up equally with the sides of the neck. There may be other ways of doing this step.
I tightened the strings in the reverse method to above (ala car wheels) until I was close to full tension. I then used the tuning method mentioned in numerous threads (Including the link above), namely, open note will be the same when fretted at the 12th, except for the 5th string where it is the 19th fret. I started on the 4th string, moving that side the bridge slightly up or down as required - when fretted at 12th, if too sharp, move bridge foot towards tailpiece slightly - check open tuning, repeat. Then did the same for the 1st string, and then checked the other strings just to be sure (this may be unnecessary though)
I found it difficult to get the tuning spot on the first go for all 4 bridges, so once it was close, (but certainly NO cigar), to tuned, I played a bunch of songs which involved bending the strings, then I left the banjo for 30 mins or so (and overnight in the first instance) before doing the final fine adjustments. Room temperature where I did this work is a very stable 17 degrees C - possibly the strings shift slightly in the new bridge for a short while, after getting to full tension? Anyway, I found if I came back after a while I was easily able to get the bridge in correct position using a tuner and the open string/fretted string method.
With Steve Davis's bridges, all without exception were canted slightly, rather than straight across the head, once in tune. By that I mean, that portion of the bridge where the 1st string goes was slightly closer to the neck than the 4th and 5th string side (of the bridge).
That's my current method of installing a bridge on a banjo.
Verdict on Steve's bridges? The final arbiter (my wife) is not a musician, but does love opera and "romantic" classical, especially Beethoven and Tchaikowski, so I played the opening bars to Moonlight Sonata as a final piece. Her comments? "Gee, those new bridges sound louder than the original, and different, but they're all nice!".
My opinion? I agree with my wife, so I'm keeping all 4! Yes, greedy, I know, but something makes me think that each bridge may come into its own with different tunings.
I hope this helps anyone starting out on their first bridge replacement.
I would be interested on any feedback on why waiting a while before doing the very final string adjustment helps. The strings on the banjo are about 4 months old, and will need to be replaced in the next few weeks. I deliberately kept oldish strings on my banjo to trial the new bridges with.
cheers,
Chris.