Focus On: Bridle Strap Replacement
What is Piano Bridle Strap and Why Do They Matter?
Bridle straps have a primary and a secondary purpose. One function of the bridle strap is to assist the hammer assembly in coming back to rest position after a note is played. Although this is a redundant feature, in that there is a part called the hammer butt spring that ensures that the hammer returns to rest position, it does become important in instances where a spring has slipped out of place or is weakened or broken. When the hammer does not return to rest position, the hammer will likely misfire when the key is pressed.
The most important function of bridle straps, however, is that they help to hold the action of the piano together so that it may be removed and replaced in the piano without damage. If bridle straps are missing, servicing the action is a real problem, in that removal and reinstallation of the action may easily result in broken parts when the action is put back into place.
Illustration of the problems involved:
If the action of an upright piano is removed for servicing and a bridle strap is broken or missing, the lower portion of the mechanism (the wippen) will swing down.
At the same time the portion of the action which rests upon the key will also swing down too far, as shown in the above photo. This is where trouble can occur.
When a bridle strap is missing, and the action is returned to the piano the jack (the vertical part shown in the above photo) is prone to jamming up against the underside of the hammer butt.
In such a situation, if the action is pushed into place with a bit too much force the lower flange can easily break from the excess pressure, necessitating replacement.
With new bridle straps installed, removing the action for necessary routine piano maintenance doesn’t cause a problem, in that the wippen is held correctly in position.
The lower flange is not exposed to undue stress when the action is returned to the piano, saving the time and expense of unwanted repairs.
If only some of the original piano bridle straps are broken or missing, must the entire set be replaced?
Is this a job I could do on my own?
This would not be a repair which the owner would be wise to tackle. The piano action is a complicated mechanism involving thousands of individual parts, where more things can easily go wrong than right for the average DIY’er. Needing just a few broken parts replaced would easily exceed the cost of having new bridle straps professionally installed.
As a professional, I have the tools and the experience to do the job right the first time. Once this job is done, by the way, it will be good for decades into the future. Replacement bridle straps (both cork and spring clip) are the finest quality available anywhere.
How will the repair be accomplished?
Once the new set of straps is in place, adjustments will be made to ensure that the action is held together correctly, therefore preventing unnecessary damage to the action when removed and replaced for needed servicing.
