Touring - Rim with 5700 km lifespan?

I changed my rear rim right prior to my cross-Canada, to a Mavic A319 36 holes due to cracks at spokeholes in the previous rim. I noticed cracks on the rim again after 5000 km. I am in the 150 lbs range, and the bike and the equipment weighed 95 lbs. Road conditions got worse in Ontario and Quebec, potholes type. I found that the wheel was built with really tight spokes. Anybody can comment on this info? Thanks Kati

It would appear that These guys (http://www.mountainbike-expedition-team.de) also found mavic rims (http://www.mountainbike-expedition-team.de/slides/bikes.html#kaputt) not up to the job for rough roads. By the looks of it they now use a mixture of Alesa and Rigida rims, interestingly enough the Rigida DP2000 which they use on the rear is a deep V section non eyelet rim which goes against the conventional wisdom of eyelets being better.

It is said that 26" rims give you a much stronger wheel although I haven't calculated this myself. The only other suggestions would be to use double or triple butted spokes to reduce shock loading and maybe use wider tyres - this is easier with 26" as you have the world of mountain bikes on your side. I'm not sure what the widest 700c tyre is but I would doubt much above 37mm exists. Do you know if your spokes were butted or plain guage?

For 700c there do exist a number of deep V rims which may be stronger - check out Rigida (http://www.rigida.com/) for the 700c version of the DP2000 and other delights.

Not that I have any experience of hammering a rim for 5000km non stop!

for heavy touring, i use phil wood hubs (old-style freewheel), with 48 spokes
(dt triple-butted) in a 4x pattern. originally had sun cr18 rims, but the rear
was not up to the load. after "only" 15tkm, cracks in sidewall and spokes pulling
through, replaced rear w/ sun rhyno lite. this set up (bike+gear+trailer+water=175lbs,
plus my 185 pounds) has held up for 25tkm. if you go with sun rims, try to find
a NOS set, made in USA, rather than the new, cheap chinese metal.

normally run 700x38, 700x42 will barely fit between the stays. saw a set of x45's
once, never would have fit....

My Mavic T520 36 hole have rolled over 6000km with no problems. I weigh 200lbs, the bike and gear weight around 100lbs.