I got inspired to write this post after my experience with my Victor Super Waves 30 today. There was a very small crack (though significant enough to worry about) on one of the grommets of my racket.
I've gotten the racket off one of the guys on the BC forum but I don't think he knows about the crack either. If he did I curse that he lose his sight from repeated shuttle trauma. But I'm a nice guy, so here's my benefit of the doubt.
Anyway, here's some of the things I'd look out for (from experience):
1. Racket Condition
This is a given. From my experience, if the guy from the forum says it's 9/10 it's probably got a few chips here and there... For my standards, 9/10 means a mint condition (no scratch, no chip, no peel) racket with the original grip removed.
Anyway, you can repair the peels and chips with a suitably colored marker pen, but do make sure that the damage is only skin-deep. Some clashes may leave invisible cracks in the structure that will only show upon stringing.
2. Unskilled Stringers
Which brings me to my next (and currently quite sore) point - the stringer. In my honest opinion, the stringer's job is far more skill-intensive than most would think. With so many rackets with different stringing styles and frame make, it's easy to get the balance right.
A racket is most vulnerable when stringing because the high tension is unevenly distributed to different parts of the racket. If a racket has an existing compromise to its structure, you're one simple pull away from a loud "pop". That's the carbon fibre giving way and your new excuse to buy a new racket.
Most stringing cracks happen along the grommet lines where the structure is the weakest, and also when applying high tensions of up to 27lbs and above.
When purchasing a second-hand racket, check for damage to the grommets (if they're deeply cut) and also the frame beneath them. Run your fingers along the side of the racket frame to check for small bumps which may have occurred when the frame collapses from the high tension.
Made in China. Beware these three words. I would like to say that while some racket companies produce their lower end rackets from China (i.e. Yonex), there are an awful lot who will charge you high dollars for some low-end stuff (well, my SW30 was made in China).
I'd stay away from anything made in China (whether authentic or counterfeit). Taiwan and Japan for me please. I'm not saying stuff made in China are of lower quality. They're just of a considerably lousier consistency.
This one is also a given, and runs the last on my list because it's probably the first question that goes through your mind when you consider buying a second-hand racket.
"Is it original?"
In light of everyone who's every paid a premium for a counterfeit racket, all expensive racket companies have some sort of a way to justify the top dollars you pay. From some hologram sticker to a laser-cut serial number, do make sure to check out their websites to find out.
And also, if the deal's too good to be true, it probably is.
Well, that's the end folks. If you've got any more tips, do let me know by dropping a comment and I'll update this article accordingly.
All the best in your gear acquiring endeavors!