Originally Posted by extecher

This topic has probably been fought over dozens of times here, but I didn't find a thread that specifically addresses this, so here we go:

Generally speaking, buying used gives you more value for your dollar than buying new, so it's always good to look at the used market, especially now that the craziness of the COVID bike market is starting to calm down. I'm on the look out for my n+1 bike to supplement/replace my 2013 Giant Defy 1 (Full Tiagra--professionally fitted for me). I ride with a bunch of triathletes long distances and have the itch to get something a bit more aggressive, so perhaps a tri bike to supplement my current bike and/or racing bike I can attach aero bars like I have on my current bike. So I'm looking at bikes and am finding some older (pre-2010) carbon bikes with 105/Ultegra groupsets and it's got me wondering about what point does the bike I have is a better ride than, say a 2007 Lemond Triomphe Carbon with Shimano 105 (95% of its life spent as an indoor trainer) that's for sale in town?

I'm not looking for specific advice on the bike per se (You can give me that though!), but rather what's the point nowadays where a newer bike with aluminum frame or a lower-end groupset is the better bike than an older high-end bike that's full carbon, has a 105/Ultegra/even Dura-Ace, and all the other goodies? I've got general knowledge about bike materials, frames, and groupsets, but I'm clueless about specific materials and groupset advancements.