Mavic 319 is the strongest rim I've used. I have them on my 29'er MTB and my street bikes. The rims hold true no matter how badly I abuse them. Mavic 719 are strong too, cost twice as much as the 319, 40 gms lighter. Another good rim is the Sun Rynolite. IMHO, 36H is better for Clydes, 32H is OK.