- 1 1/8 steerer tube, or maybe tapered
- Threadless a-head headset in any common SHIS type. Threaded ones won’t last as long.
- QR or common thru-axle
- Any common BB standard (threadless ones are actually fine but require a well made frame, and you’d be surprised how many expensive frames are not well made)
- Always a round seat post and get 27.2mm if you can. Bigger if you care about dropper posts
- Rim brakes are fine unless you are doing serious off road. If going disc, hydraulics offer great performance for the price.
- Flat bar shifting components are much more interchangeable and better value that drop bar!
- If going drop bar, consider older 2x11 speed mechanical equipment. It’s much cheaper and it was competitive at a pro level not so long ago.
- External cable routing!
- Aluminium is uncool, but it represents a sweet spot in terms of weigh/cost/durability
- Tyre volume, not frame material, is the most important factor in comfort
- Never buy a bike that doesn’t fit you
These tips won’t get you the best bike (in terms of absolute performance) but it will be reliable, easy to fix and good value.