How to buy (inspect) a second hand (used) bicycle - Marathon version

Things to consider when buying a 2nd hand (used) bicycle.
How to check if the bicycle is in good condition, what to look out for.

I plan to make A LOT shorter version, covering how to inspect bicycle's mechanical condition (frame, and other parts).
This video is long, in order to cover a lot of topics that I suppose novices will find useful.

- Contents -
00:00 Introduction - and disclaimers
02:07 Do 2nd hand bicycles save money?
04:05 Looking at 2nd hand bike offers (Craigslist etc.)
07:28 First impression - gut feeling
10:23 Inspection before a test ride - and reasons why
11:44 Checking the frame
15:33 Inspecting the wheels - bearings, spokes, and rims
23:15 Fork, suspension and bottom bracket bearings checkup
25:24 Are the brakes broken? :)
27:25 Rack, mugduards, handlebars etc.
29:49 Drivetrain, shifters, and derailleurs
34:49 Dynamo lights - checking if they work
36:11 Rear derailleur hanger problems
38:49 TEST RIDE... explained in a lot of detail :)
42:32 Saddles - a few words on those
43:38 Fitting - comfortable riding position
44:20 Conclusion - are 2nd hand bicycle worth buying?

SLIP: I said "unlocked", but meant "bicycles left outside locked".

- Useful links -
List of all the BikeGremlin videos, sorted by categories:
https://bike.bikegremlin.com/youtube/

My article on 2nd hand bicycle inspecting and buying:
https://bike.bikegremlin.com/1102/looking-second-hand-bicycle/

What kind of bicycle suits my needs:
https://bike.bikegremlin.com/865/which-type-of-bicycle-suits-my-needs/

Fixing a stuck hydraulic disc brake caliper piston:
https://www.youtube.com/watch?v=K6mG6UjBh0Q

First bicycle saddle related article, in the series of 5 short ones:
https://bike.bikegremlin.com/2954/bicycle-saddle-materials-explained/

Setting up a comfortable riding position on a bicycle:
https://bike.bikegremlin.com/2819/setting-comfortable-cycling-position/

Video explaining basics of bicycle frame geometry and fitting (setting up a comfortable riding position):
https://www.youtube.com/watch?v=ajoLYCn7IcM

How to securely lock a bicyle outdoors:
https://bike.bikegremlin.com/434/how-to-lock-a-bicycle/

id: 1028