This article is from the Recreational Figure Skating FAQ, by Karen Bryden with numerous contributions by others.
There are some relatively objective signs that a boot has worn out or
is being used beyond it's limitations and others that are purely
subjective or require reference to a coach. Certainly, a skate is
finished if the leather in the boot has started to wear out --
fissures in the inner lining, rips/tears in the outer boot or a
cracked/crumbling sole that won't hold screws.
Judging when a boot no longer offers adequate support is more
difficult. If the top flops over of it's own accord, it's obvious, but
more subtle signs are when the normal creases which afford forward
flexibility begin to look like accordion pleats that go all the way
around the skate -- a sign the a the boot is free to flex sideways at
Some more subjective signs are the feeling that you need to tighten
the laces more to make things work, even though they are still tight,
or the feeling that your foot is free to slide around in the skate, or
your heel lifts even when the laces are tight. You might also feel
that you're having trouble keeping your ankles erect or holding clean
edges on tight edges, turns, spins or jump landings.
On the final front, your coach/instructor may make observations that
your boots aren't doing their job or suggest that it's time to
upgrade. This may be based on close observation or rule-of-thumb.
Asking your instructor is always a good idea, while talking with other
skaters can either be helpful or lead to a lot of confusion.
Keep in mind that boot requirements are highly relative. Given the
model of boot that you have and the amount of "wear" you've put on
them, they may be entirely adequate for what you're doing, or they may
be an obstacle to further progress. A recommendation on buying new
skates might differ depending on whether you're skating recreationally
and just interested in picking up some jumps, or planning to go from
singles to triples as quickly as possible to get into serious
competition. Also, the recommendation for a petite woman would be
different from that for a mid-sized athletic woman or a mid-sized or