I commute on a early 90s rigid cro-mo mtb beater, it's about 27 pounds. I'm about 210 pounds. 20-mile round trip commute on rough city streets, year-round (rain, snow, etc.)

I've been going though about one rear rim every two years or so - they generally have been cracking at the spoke holes, even though I ride cautiously and avoid potholes, etc. (some are unavoidable, of course).

The last wheel set I bought was a Mavic Crossride with 24 bladed straight-pull spokes, F/R. The rear wheel went in two years (maybe 4000 miles), so I just picked up the current Crossrides - they only have 20 bladed spokes F/R.

I was about to mount the cassette on the new 20h wheels and had a thought - my wife's mtb has 36h wheels. It is a 1994 Specialized M2, in great shape with 99% original components. These are the original wheels - Specialized Z-21 rims on Deore LX hubs, no spoke hole reinforcement, they look like fairly cheap rims, but still in great shape with low miles.

My question - would these old but low mileage wheels be a better choice for my commute (I'd give my wife the new 20h wheels, she uses her mtb only a few times/year for casual coffee-shop type rides and she weighs about 80 pounds less than me!). One issue is I'd be taking an original part off her bike, in case she ever wanted to sell it...and I don't know if maybe the newer Mavic wheels would just as strong or stronger than the old school design?

Once I go through whichever of these two wheel sets on my commuter I will eventually look into a very stout 36h wheel set with traditional build, but for now I just need to decide between these two wheel sets.

Any thoughts?