The 26" Ryde Andra's are renowned amongst bike expeditionists as the ultimate durable rim for heavy loads on various terrains. We have chosen the 36 hole for increased strength. They are no compromise rims.
Around-the-world cyclist Alastair Humphreys' (http://www.alastairhumphreys.com/roundtheworldbybike) biggest mechanical issue was broken spokes under the weight of the rear load – a strong rim helps minimise the stress on the spokes, and the Rigida Sputnik is one of the strongest out there.
All of our wheels are handbuilt in Sussex. Wheels hand built by an experienced builder can significantly increase its strength versus those machine built. We have recently up-specced the hubs on the Kibo to the Deore LX due to the combination of their excellent sealing and strong axle.
For heavier riders we can tweak a few things - the frames' tubes, the rim choice (Ryde Andra 40 instead of 30) and the tyres (2.15 width) - please get in touch if this is of interest