Unpopular opinions welcome. How long do you think it will be until 23c tires are almost impossible to find? Full disclosure, one of my favorite bikes will only fit up to a max of 23c - but finding quality tires is getting tougher each year.

I plan to swap all my 700c x 23 bikes over to 650b .... oh, wait, didn't we have a thread about that?

continental, michelin,vittoria, veloflex and panaracer still have this size.I don't see any reason why it should disappear.700*19 and 700*20 completely disappeared from the market.

I still remember running 19s

More recent 25c tires (e.g., Continental GP5000) are narrower than previous 25c tires (e.g., Continental GP4000 S II). 700x25c GP5000 tire measures < 23 mm wide when first mounted on my 17 mm (internal width) Mavic wheels, but after multiple rides and pre-ride inflations stretched to 25 mm.

Considering big name companies were making race bikes that wouldn't take larger just a few years ago, I'd like to think the demand and the supply will remain for some time.

2039 will be the year that you can no longer find quality 23mm tires.
Less than 2 decades- better stock up!

Store 'em cold, away from UV light and in a nitrogen environment and they should be ready to roll for the next 3 or four decades. Tubulars gently inflated, again with nitrogen.

The way the roads are going we will all need at least 40c by then.

Probably longer for tubulars than for clinchers.

Probably 2080 maybe but probably longer. We can still get the various sizes of 26" that aren't 559 (the common mountain version) quite easily and ISO 630mm is still available fairly easily though less common but I know we have probably 30 ISO 630mm tires in stock at the shop from 3 different manufacturers (maybe 4) 700c is an extremely common size so I would doubt they are going to get rid of 700x23 anytime soon. It is very very very rare that you will find a bike these days even some older bikes that cannot fit at least a 700x23. I am sure there were some odd specialist bikes that only went to 700x20 or something back in the day but I would say that is an outlier. I would say you are fine. There are currently 39 700x23 tires from 8 different manufacturers. available on QBP, one of the largest distributors in the U.S. I know there are others making tires like Specialized (who have a few options in 23mm) and if you want cheap tires Serfas still is around somehow and I know there are others, some good some bad. I would doubt the size is going away. However you may not have that bike in 20 years.

I don't think I'd worry. Consider all the technically obsolete gear that is still available today. Heck, you can buy freewheels, 27" tires, 1" threadless forks, threaded headsets, <10 speed cassettes, and pretty much any NOS part you might need if you're patient and have the cashola. A lot of cyclists think that as soon as new bikes move on from a technology or standard that it will totally disappear overnight. I understand the worry, but it's not realistic.

Consider the amount of bikes and riders out there in the world that still utilize whichever technology you're worried about disappearing. If there's money to be made, product will be supplied. You're right that selection variety will diminish however. For example, 27" tires have been phased out for a looooong time. They're still available new, however, there's exceedingly few options nowadays.

Another example is rim brakes and mechanical shifters, which are being phased out of the mid to top tier groups. Support for these will be available for quite a long time regardless. There's far more in service bikes out there in the world with mechanical shifting than there is electronic. There's probably more in service rim brake bikes out there than disc. It's still quite viable from a business standpoint to supply products to support those bikes, as many are and will still be utilizing them in the future.

I reckon your skinny tires will be supplied by someone, somewhere for longer than you'll realistically need.

If anything, aren't 650b road wheels, and particularly rim brake, HARDER to find than 700x23 tires? I've considered going down this path on a couple of my bikes, by using long-reach calipers so as to get a fatter tire onto an aging road frame, but whenever I've priced it out or gone googling for the needed bits and bobs I always came back to "well I guess I'll just squeeze some 28/30c into the space I do have and be happy."

I recently picked up a pair of Vittoria Corsa 700x30. Mounted on 17mm rims, they measure at, generously, about 26.5mm.

They're very nice and run smooth, and probably are designed to go with a wider internal x-section, but on my wheels they are skinnier than advertised.

My point, restated yet again, is that we just had a thread about how 650B tires were disappearing, and everyone needs to panic, and soon we wouldn't be able to ride anymore .... and then half-a-dozen people posted web sites with ample offerings ......

+1, buy a few, store them. A vacuum sealer used for freezing food would make a good job for the long run.

You might find a new bike more fun.

I did.

time for a new frame