Hi everyone! I've been interested in getting into touring or bikepacking for a while now but have yet to get out on a trip. I have a 90's Bianchi Ibex (mountain bike) conversion but have a question about tires. The tires I currently have on there are Nokian all weather slicks (26 x 1.3). That's just what the bike shop had when I bought the bike as it originally had massive tires that I didn't think suited my riding. Now I'm wondering if they're best for what I want to do. I don't anticipate doing any major tours in the near future, just thinking about weekend trips but want to have some flexibility if I run into some gravel or dirt trails (though nothing major). Should I be considering wider/non-slick tires that are more suitable for different surfaces?

I also wonder about tire/wheel sizes because I still haven't found a good explanation. My current tires are 26 x 1.3 but I've come across some on Facebook Marketplace that say "650 x 35B - 26 x 1.5". Is there a difference between 650B and 26" or are they pretty well interchangeable? Thanks in advance!

To answer the second question first. 26" and 650b are not interchangeable tires, the rim size is different. 650b is a larger rim diameter. Sometimes people swap rims but this will usually only work if you have disc brakes as the pads on rim brake bikes are set for whatever diameter comes with it. There are some exceptions to that but for your question the answer is look to 26" tires.

Tires are a hot topic with everyone having their favorate. Those Nokians are pretty cheap and heavy. For a proven tour grade tire try looking at Schwalbe Marathons as a choice. Others will recommend more.

Cheers.

Get a quality slick 1.9" to 2.1" folding tire and run it at a lower PSI than you have right now. Plan on at least $40/tire to get something that is made to roll quickly. The more knobs(lugs), the slower you go.
You dont need tread to ride on dirt and gravel paths.

I think you should do a couple weekend trips on what you have. Then if you enjoyed it, start thinking about other tires.

There are several different tire sizes that have been referred to as 26 inch over the years. If you look at the tires on your bike you probably will see the number 559. That is the common 26 inch tire for use on mountain bikes. But the size known as 650b at one time decades ago was also called 26 inch, that tire would have a number 584 on it somewhere and now people call that 27.5 inch. And there is another 26 inch tire that was commonly used on British three speed bikes several decades ago, that would have the number 590 on it.

More on sizing issues here.
https://www.sheldonbrown.com/tire-sizing.html

But these days if you walk into a bike shop and ask about 26 inch tires for a mountain bike, 99.9 percent of the time they will know that you are talking about a 559 tire.

Actually lots of little low knobs roll better than fewer larger higher ones. Not like a slick but closer. Something like the Kenda Slant Six rolls pretty well on pavement if you want/need knobs for when off pavement. I road tour on slicks, or near slicks, but have done mixed surface tours on XC race tires and found them to work pretty well.

BTW, on a slightly different topic. I tend to wear out what I have on the bike before worrying about changing tires unless they are something pretty unpleasant or very unsuitable for the tour I am planning.

Yes thanks for clarifying, my other post was poorly worded.
I just meant when considering knobs vs slick- knobs roll slower and worse on pavement and hardpack dirt or packed stone are surfaces that dont need knobs.

If you're looking for new 26" tires for mixed surface check out the Maxxis DTH (file tread) or Schwalbe 'Billy Bonkers' (lots of little low knobs). Both are folding and very lightweight.

I agree with the idea of just trying out a weekend trip to see if you like doing this. If the tires on your bike are in good shape you will be ok.
I find a 26x1.5inch tire to be a good all around width for riding on all kinds of surfaces, and any reasonable tire will work well for predominantly paved road and dirt riding.
there are many good tires at a reasonable cost for your needs, and they will last for years, so perhaps see if you actually like bike touring----plus you may have to buy a rear rack, tent, camp mat, sleeping bag etc.....so hold off on new tires if three existing ones are new.

if you really want new tires, then people can give good suggestions.
And yes, 25-40 dollar range generally will mean a good tire.

do you have the stuff to try touring, panniers?

That would probably be a good idea given there are other things I will need to get. I do have panniers and a rear rack but need to get the camping gear. I have a car camping trip planned later this summer so I'm getting that stuff anyway so at least I know I'll use it a bit.

I suggest Schwalbe Hurricane. The middle part is basically a slick, yet there are some aggressive teeth on the sides to help with the grip on rougher surfaces. Relatively cheap, fast and reliable tyre.