if the 36 dont hold up, find a khs dealer. they offere a mtb tandem with 40 spoke wheels and the sell a set as a replacment item.any khs dealer can get 'em $250 is what I was quoted for a pair. I got lucky and got just the rear for $85 bucks. thay are xt tandem hubs hand laced to ryno lite rims. we had to respace and redish the wheeldown to 135 from 145 but it only took a few minutes and was really easy. I am thinking of getting a complete set so they match and I'll have an extra rear wheel set up.