Originally Posted by
qspencer
I've been wondering for a while why tandems have sometimes used non-standard (and therefore hard to find) dropout spacing. Is is all about reducing wheel dish, or are there other considerations I wasn't aware of? It seems like 142x12 makes a lot of sense for tandems. That would make it possible to use a lot of different wheels.
Correct. The idea was that wider rear spacing reduces wheel dish up to the point of symetrical (ie: 160mm) and therefore a stronger wheel. If building the ultimately strong wheel destined to carry heavy loads is the goal, then go for it. However for lighter loads and those desiring more "race like" performance, there is less need to over build wheels, especially with today's components. For example, there are plenty of tandem teams using 130mm spacing and single bike wheels without any issues - given their team weight and usage needs.
I had thought 145mm was a decent (tandem) standard to stick to, but after shopping for disc hubs was rather appauled at the poor selection available when compared to the mass market world of single bikes. Either a 142mm X12 (thru axle) rear, or a 135mm QR rear would be my choice for our usage needs. Bizillions of hubs to choose from in those formats.