Well obsolete here.
Gears: 3×9, 3×8, 1×8, 1×1.
Cranks: ht2 xt on 3, and square taper on 4th.
All headtubes are 1.125″. Oddly, the oldest one is the semi-integrated one.
I have never even sat on a gravity dropper seatpost.
Forks: 09, 07, 05 and rigid.
Brakes all circa 2006 apart from ancient v brakes.
One bike has an oversize stem/bars, the others all obsolete 25.4mm.
Inner tubes throughout.
It makes my bikes, oooh, 2-3lbs heavier than their new equivalents in terms of price and ‘purpose’, but also made them and spares for them affordable. Basically if I tried to keep right up to date with latest bikes and technologoes with my disposable income, I would have a crappy commuter plus one xc bike as opposed to fs xc, singlespeeed and freeride bikes I have at the moment. This way works for me.