I’ll raise the niche stakes here 🙂
I’ve survived 14 months of riding a home made steel fillet brazed e-stay singlepeed rigid 29er frame with Crests around the various rocky stuff in the lakes, lancs, yorkshire, scotland and swiss alps – with an upgrade(?) to include 6 of those new fangled “gears” for the alps riding.
I’ve then gone on to build another frame (from a fresh pile of steel tubes) with some more regular chainstays and 100mm suspension forks. That seems to be doing fine with the same Crest rims / riding area (and a whole 7 gears for the austrian alps – I guess one extra cog per year as I get progressively more frail)