I was just looking at my rear rim this morning (Velocity Aerohead) and I noticed a few tiny little cracks where some of the spokes enter the rim. How big of a problem is this and how would I know if I needed to invest in new wheels?

Right now I'm on the Velocity Aeroheads laced to Shimano 105 hubs. They're 32 spoke front and rear. What would be an equivalent quality wheelset?

Thanks.