Would you happen to remember any of the verses where that phrase is used? I suspect you're talking about something like 13.147, 14.26, or 15.386. I don't have the 2014 Penguin Classics version on hand, but I see that at least this translation by Stephen Mitchell is using the phrase "double-curved spear/spear points" there.

All these verses have this particular combination of ἔγχος^1 (egxos) + ἀμφίγυος^2 (amphiguos). It's an epithet that shows up several times in the Iliad, and it's better translated as "double-pointed or double-ended spear," i.e. the spear has a spearhead on one end and a spike on the other, which could be stuck in the ground. That spike (the σαυρωτήρ, sauroter - which means something like "thing for killing lizards," by the way) is mentioned explicitly in another part of the Iliad, 10.153:

his comrades were sleeping with their shields beneath their heads, but their spears were driven into the ground erect on their spikes

For a much later example, see here.

If indeed these are the instances where your translation uses "curved spears," then I think the confusion is coming from the fact that, in other contexts, that adjective ἀμφίγυος can refer to things that are curved or bending around.

1. http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3De)%2Fgxos

2. http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Da)mfi%2Fguos

[Edited to fix a couple links.]