How long can I ride my bike with a worn cassette? I took my bike to the mechanics the other day and along with needing my chain replaced they said that I also need my cassette changed and the front cogs.

I was wondering how long I can ride my bike now with a worn cassette before it becomes unridable? The teeth on the cogs seem a bit worn but they are nowhere near as bad as what I have seen on other videos.

What can I expect to happen when the cassette does start to fail? Gear slipping? Crunching sounds?
In my experience, skipping in certain gears at the rear is the first sign.
Usually in the most used sprocket.

Then the chain becomes worn - and perhaps starts to snap - and when you order a replacement - it skips all over the place because it is being run on an overly worn drive-train. You might be able to salvage the old chain and run it for a bit longer - but sooner or later - you have to bite-the-bullet and buy complete new drive-train.

But if your current drive-train is happy and not exhibiting any malfunction (keep that chain clean and oiled) - you could go for many many many miles on it.