Q. Can you please advise on guidelines for traveling with tennis racquets, particularly storing in cars and air travel.
A. Most racquets, unless strung very tightly, or already banged-up, are pretty tough. However, like most people, racquets don’t like to be “bent out of shape” nor experience extreme temperatures, particularly at the same time. Your email signature indicates you are an engineer, so you probably understand better than I do how specific material’s integrities and properties change at certain temperatures.
Basically, if possible, best not to store or leave your racquets in the trunk of the car on hot or frigid days, and don’t place heavy items on top of them in any weather. The safest way to protect your racquets when flying is to take them as a carry-on item. If you check it as baggage; try to use a thermal or pro racquet bag, or inside of hard-sided luggage. Cargo holds are much more an issue of “how it is stored” under other baggage, than temperature related. It is too bad you don’t see hard-sided racquet travel bags like you do for skis, golf clubs and fishing rods.
Touring pros who take racquets as carry-on are more afraid of lost luggage than damage from the cargo hold. Having multiple racquets next to each other provides more protective support than a single frame all by itself. While it is always nice to travel light, if you are concerned and opt for checked baggage, place your racquets between an old racquet which will provide support and buffering.
One packing note is that frames are more resistant to breaking from horizontal profile edge stress than vertical. Have you ever seen a pro slam a racquet onto the court in a fit of temper? If they want to break the frame, it is smashed on the vertical face edge where impact is focused onto a small area already under stress from stringing tension. If they want to vent steam without breaking the frame; it is slammed down flat-as-a-pancake on the horizontal profile.