what number of grinds are you guys getting per rim? how long does each one last you? i get two weeks or so max per grind on my monty mod rim, which doesn't seem like it would take too long to kill the rim. i'm wondering if i should just get a bunch of cheapo rims for my stock and grind those rather than grind my D521 (which i'm running now) and lose it in a short time.
The D521 is much harder aluminum. You probably won't wear the grind down nearly as fast as you did with the monty rim.
I have several ground rims. The grind on a Monty rim only seems to last a couple days. I also have a couple D521s that I ground and I only have to grind them every couple months. The Echo rim that I am using right now seems to be somewhere in between the Monty and the Mavic. I have had it about a month and it will be needing another grind soon. I usually don't grind my rims as soon as the previous grind starts wearing down. Normally if I keep them clean the brakes grab well even with a worn down grind. Sometimes I just use Simple Green until it gets close to time for a comp and then regrind. This should make my rims last a little longer.
I am up to my third? fourth? grind on an Echo/Alex rim.. they last about 3 months, this last one went for almost 4 but it got shit in the dust so I grinded again.