2008ish Orbea aluminium road bike - First road bike, now permanently trapped on the trainer after being ridden, raced and commuted on.
2012 Specialized Epic - Raced and commuted on lots, not so busy now, but it’s not worth much and it’s still fine, so not going anywhere.
2016ish Trek Marlin aluminium HT - Bought to have a kids seat on the back, which it did until the start of this year when I rebuilt it as a 1x, flat-pedalled, gravel-tyred commuter.
20?? Probably Chinese aluminium track bike - Bought secondhand. I race track on it. It’s fun.
2017 Cannondale Supersix - carbon roadie. Riding and racing. In hindsight I should have waited for the inevitable next model with discs and more clearance, but I enjoy re-cabling and tuning and all that. I committed to it enough to buy some race wheels for it.
2021 Focus Atlas - aluminium gravel bike, after cancelling the order for a carbon hardtail. Very happy with the decision.
Had another carbon roadie which I sold so I could buy the Cannondale.
I tend to hold onto my bikes because the price gap between selling one and buying another is almost always too much to justify.
Waxed chains on all of them. Less cleaning, less water and cleaning products… less component wear…? Sounds sustainable!