My 18-year old Cannondale Hybrid has Shimano Altus C10 components. The bike has been a workhorse. The Altus C10 worked flawlessly for all these years. Now I want to get a new bike. Are new Altus components still good and reliable?

I have 2012 Altus components. Work quite well, and 2013 should be better due to Shimano's trickledown policy.

Altus is pretty entry level, but should work OK. That said, I would say that since you seem to keep your bikes a long time, you might want to consider going up a step or two and go for Alivio, or even Deore components.

Altus components are as good and reliable as others from Shimano. Case in point is an Altus equipped mountain bike I rented in Alaska. The bike and derailleurs had been through a lot and the finish on that rear unit was scraped and worn. But it did the job of shifting cogs on demand while keeping the chain aligned.

just beginning to get into biking. so my opinion might not be valid to others. but I do know this.

Sure Altus is the entry level components, but I believe is also how you treat it. regular cleaning and lubing will make it last long. same goes to anything, if you treat it well, it will treat you well.

the best quality things out there will break/wear out quick if it has been mistreated.

I have one bike with a Shimano Acera shifter (one step above Altus) and a Sora rear derailleur. My other bike has a Shimano Alivio shifter (two steps above Altus) with an older Alivio rear derailleur. I find both shifters to be responsive, but I find the Alivio to be distinctly more smooth.

I have an Atlus front derailleur and a Deore rear derailleur on my 2013 kona. At first I was really concerned that the Atlus was going to be junky and that I should have the shop swap it out for a Deore when they were doing the intital assembly, but decided to wait and give it a shot. Guess what? It works fine. It shifts properly and reliably and I haven't had any issues with it. I take care of it, keep it clean and the pivot points lubricated, and am glad I saved the $40+ I would've spent buying a higher end FD right out the gate.

As I've gotten more bike experience, I've taken more of a "ride what you have until it doesn't do the job anymore" approach. It's been working out for me.

If properly maintained Altus components can give many years of reliable performance. I just upgraded the components on my wife's MTB. After a thorough cleaning and a little oil the 16 year old Altus derailleurs I took off hers went on my beater bike. They still function just fine.

Over 2000 miles on my Altus rear derailleur and it's performing flawlessly. Not as smooth as my older 105 deraileur, but it does the job.

Nothing wrong with Altus.

If you want better shifting, upgrade the shifters to one of Shimano's better flat bar shifters. Makes a big difference. Which one will depend on what speed you get. R440 (9 speed) and R770 (10 speed) for instance are really nice shifters.

Don't worry, the nicer stuff won't always shift nicer either. I tested out all Altus......all Acera......all Alivio......and All Deore. You wanna know what differences I noticed?? NONE, except for the number of gears! In fact.....dare I say I'm so used to (and pleased with) my Altus shifters & Alivio RD, that anything else would probably feel weird.

Getting your stuff setup right will make a bigger difference than make/model.

In fact, if you want real proof, you already answered your own question in your OP!!