Forgive me if I'm posting in the wrong area. Newbie here.

I have a gravel bike that has rims with 622-19 on them.

The tires it came with are 700c 35

I would like to replace the tires to something slimmer, what should I look for?

I hear good things about the continental gp4000s, would those fit?

Thanks!!

Go with 700 X 28's

I used them to tour on.

Rims with a 19mm internal width should comfortably fit anything down to a 28mm tire. You could perhaps get something smaller to seat, but it's not "recommended."

What sort of tire are you looking for / what's your goal with going narrower? GP4000S do have a 28mm size available, so that would be an option if you're looking for a decent road slick.

I've been riding more road lately and really getting into it. Just wanted to see if it makes a difference going narrower like most road bikes.

My friend has some 25mm that he's offering to just give me, would that work?

Copied from Sheldon Brown's website. According to this 28 mm is the narrowest acceptable tire for your rim.

Which tire fits safely on which rim? Tire Sizing Systems Go to the fifth table down on the page.

700c tires have a bead seat diameter of 622 mm. The other numbers mentioned are widths, so you've got 35 mm wide tires on 19 mm rims.

VegasTriker mentioned the rim/tire size chart on Sheldon Brown's page above, which originally came from the ETRTO (European Tire and Rim Technical Organization). It shows 28 mm tires as the narrowest you should fit on rims with a 19 mm (internal) width, but the chart has a reputation for being conservative. You could almost certainly use 25 mm tires, even if the ETRTO considers it a less-than-ideal match.

According to Continental's web site, 700c GP4000S II tires come in 20, 23, 25, and 28 mm widths. Stick to 28 or maybe 25 and they should fit just fine.

You'll likely be able to make it fit.

Be aware that tires that are too narrow for a rim have to stretch out for their bead to dig into the rim's hook. This can make it harder for tires to take on an appropriate shape, and it can make them more prone to catastrophically rolling off the wheel.

Keep in mind that much of what you'll be testing is tire styles. Narrow tires tend to weigh less, so they do make for livelier acceleration. Other than that, effects of width are hard to separate from tire style and pressure. For instance, if your 35mm tires have any tread designed to dig at the surface, that'll be a significant rolling resistance disadvantage compared with road slicks. Suppleness is also significant; any GP4000S in any width will likely roll better than any Thickslick in any width, even though they're both road slicks.

A huge thank you to everyone for the advice! All these numbers have been so confusing.

My friends tires are the go4000s II 25mm. I tried looking online about the fit and I've been reading that they run large for their advertised size. I hope that it's true and works in my favor.

I'll try them out and if there's any problems getting them on my rims then I'll probably get some 28mm tires for some peace of mind.

Thanks again, any other advise would be awesome, always looking to learn more. Much appreciated everyone!