So, let's think about this for a moment...
How much weight can you realistically save?
50 g per rim? Or for both...
Let's say you're an average, fit rider, weighing 70 kg. Your bike weighs, say, 7.5 kg. With a couple of water bottles, shoes, clothes and stuff, we'll make it an even 80 kg.
80 kg is 80 000 g.
If we say you saved 50 g, then you've reduced the total mass by a factor of...
50 / 80 000 = 0.9994
Yep, that's a whopping 0.06% you've saved!
Which would make you 0.06% faster if you were cycling vertically in vacuum.
At typical race speeds, on a mixed hilly/flat course over 100 miles, such a reduction would save you no more than about 10 seconds.
Worth it?