Cello Bridge Care

HOW TO MAINTAIN YOUR BRIDGE IN OPTIMAL CONDITION

Robin Aitchison example of a warped cello bridge

Keep an eye on your bridge to prevent warping like this.

Getting the best from your cello bridge.
A good bridge can last indefinitely but it does need constant care and attention from the player to stay in optimal condition. There are three cello bridge care issues to be aware of: warping of the bridge head, splaying of the legs and cutting of the strings into the string grooves.

A good start in life.  For a bridge to stay in good condition and to transmit the energy of the player to the body of the cello efficiently, it needs to stand up straight. The best luthiers are fanatical about their wood selection for bridges. We look for a combination of fineness and evenness of growth: the tighter the growth lines (rings) and the straighter the medullary rays (vertical structures) in the wood of the bridge blank, the stronger and more stable the bridge will be. Excellent bridge wood also offers the luthier more scope in the design details of the bridge.

We use top-grade maple bridge blanks made to our own design from the best French manufacturer. They source their maple from the same region as the wood we use for the backs, ribs and scrolls of our cellos, but they choose plain maple without any figure or curl.

Good bridge manufacturers always season their wood, but we like to season our bridges for at least a further five years. Like most luthiers, we also heat treat bridges before use, to release any internal stresses in the wood and give the bridge more stability during its lifetime.

BRIDGE CARE GUIDE

1. Lubricate the string grooves.  Each string groove in the bridge and the ebony top nut should be well lubricated by rubbing a piece of dry soap (see below) across the empty string groove until it is full of soap fragments. The presence of the soap will allow the string to slide much more smoothly over the bridge and nut, with far less friction.

If you want to lubricate your string grooves but are not changing the strings, tune down each string by a major third, briefly lift the string out of the string groove while you rub soap into the groove and then replace the string, tune it up and straighten the bridge. Many cellists like to use graphite (pencil lead) to lubricate their string grooves which is an equally effective method, but we prefer to use dry soap as it’s quicker and cleaner.

How to prepare dry soap. The best soap to use is of a basic quality, such as a little tablet of hard and crumbly hotel soap. Nice soaps containing oils which are good for your skin are too soft for our purpose. If you don’t have a cake of old hotel soap, cut a 1cm slice off a bar of basic soap and put it in a warm dry place for a few months until the soap is dried out and shrunken. When you scrape the surface, small flakes should come away like snow.  A little piece of soap like this can safely be kept in your cello case and used for your string grooves in the bridge as well as in the nut at the top of the fingerboard – whenever you fit a new string.

2. Straighten your bridge regularly to stop it warping.  Even if you use dry soap to lubricate your string grooves, some friction will still occur between the bridge and string every time a new string is fitted or tuned. This friction will drag the bridge fractionally in the direction of the pegs or the tailpiece, depending on whether you are tuning from the pegs or fine tuners.  It’s important to note that fine tuners drag the bridge six times more powerfully than pegs, because they are in such close proximity to the bridge. If you use fine tuners regularly, you need to keep a close eye on the bridge and correct its stance away from the tailpiece. It’s worth tuning with your pegs whenever practical to counteract the effect of the fine tuners, but every time you fit a new string, you should assume that the bridge has been pulled towards the peg box and will need straightening.  To ensure that the bridge stays upright and in perfect condition through its lifetime, we recommend checking the posture of your bridge at least once a week. If your bridge has already become warped, don’t despair: good luthiers can re-flatten moderately warped bridges (there are a variety of techniques.)

1,000 years of bridge straightening.
This 11th century sculpture in the Portico de la Gloria, Santiago de Compostela is the first record of a player straightening their bridge

A straight bridge sounds better.  It’s also important to keep your bridge standing upright from a tonal point of view as the posture of the bridge makes a big difference to the sound and response of the cello. For the bridge to function as the luthier intended, both feet should sit flat on the cello front, with even pressure on every part of the feet – so that the bridge is neither rocking back on its ‘heels’ or forward onto its ‘toes’.  Some cellists carry out minor sound adjustments on their instruments by changing the angle of the bridge; other players are less keen to experiment, but we would encourage every cellist to learn how to adjust the angle of the bridge to keep it standing straight upright. Practise straightening your bridge until you are confident!

3. Bridge straightening techniques.  

(i) Like the Santiago de Compostela player on the left, grip the bridge immediately beneath the strings in order not to break any part of it with the pressure you’re applying. Straighten the bridge gently and evenly, balancing the effort of both hands.

Robin Aitchison straightens cello bridges like this

Robin’s favourite straightening technique

(ii) This method is Robin’s favourite and works well for players with big hands.  Lie the cello across your lap or a table. Wrap your hands around the strings on either side of the bridge and brace the little finger of one hand against the tailpiece and the little finger of the other against the fingerboard. If the string grooves have been lubricated, you will be now able to push the head of the bridge in the desired direction with your thumbs. The thumb which is not pushing can act as a balance or brake to ensure that the bridge doesn’t go too far.

Cello bridge gauge by Robin Aitchison

Bridge gauge

4. Use a bridge gauge. If you are unsure how to assess the posture of your bridge, you could ask your luthier to make you a bridge gauge like the one pictured below which is designed to fit precisely between the top of the bridge and the end of your fingerboard when the bridge is standing perfectly upright. Use this gauge to check the posture of your bridge and correct the bridge angle as required. Make sure the grooves are well lubricated with dry soap before you correct the bridge angle, otherwise the strings will grip the bridge too firmly to allow any movement.

5. Watch out for splayed bridge feet.  If a cello’s front has high or steep arching, there is a tendency for the bridge feet to try to ‘do the splits’ and become splayed. If a cello accidentally rolls over onto the bridge, this also causes the bridge feet to splay apart. If your bridge legs are splayed this will have a very negative effect on tone. It is possible to squeeze the bridge feet back into place safely with your thumbs and forefingers, but we suggest you watch the new video on our website before attempting it.

6. String groove maintenance.  Only 30 – 50% of each string’s thickness should sit in the groove. If a groove is too wide for the string, this can cause a buzz; if the groove is too deep, this will cause excessive friction between the string and the bridge, which may warp the bridge and damage the windings of newly fitted strings.
We like to fit bridge vellums (small pieces of parchment) over the A, D and often the G string grooves to help prevent the upper strings cutting down into the bridge. Vellums are finer and harder in texture than wood, and therefore withstand the pressure of strings better. The narrow A string can still cut through a bridge vellum over time, so keep an eye out for this. If your string grooves are too deep or over-sized, they can be built up again by a luthier and filed back to the right shape.

7. Keep your old bridges.  If your existing bridge is beyond repair or you decide to get a new set up, ask your luthier to return your old bridge to you as it is an important part of the cello’s history. It’s also an insurance policy: if you are not happy with the new set up, you can return to the old set up or ask a luthier to make a copy of the old bridge that worked well for you.

© Robin Aitchison & Sarah Mnatzaganian February 2019