I have some rims with 23mm tires on it. How wide a tire can I put on these? The rims were originally from a 1981 Raleigh Competition. They are Araya rims 700c.

I really love ride of my other bike with 27 x 1 1/4 tires on it.

should work with 28's

In theory, any "700C" tire will fit that rim (including so-called 29" mountain bike tires), but beyond a certain width the tire tends to wobble side-to-side if there's not enough pressure or spread the rim's sidewalls apart if there's too much pressure.

In my experience, a rim that originally came with 700x23's will work fine with 700x28 tires, could work with 700x32's, and is getting iffy with 700x35's.

(Are you sure those are originally from a 1981 Raleigh Competition? Even racy bikes of that era rarely came with anything narrower than 700x25's.)

I'm pretty sure the rims are from the Raleigh, the tires are definitly not original to the rims. If it originally came with 25's, then 32's would be more likely to fit?

If you're willing to take off one of the tires and measure the inner rim width, this could help: https://sheldonbrown.com/tire-sizing.html (There's a considerative guide toward the bottom.)

- Scott

B.S.D.

The ISO (E.T.R.T.O.) System
Width Considerations

Although you can use practically any tire/rim combination that shares the same bead seat diameter, it is unwise to use widely disparate sizes.
If you use a very narrow tire on a wide rim, you risk pinch flats and rim damage from road hazards.
If you use a very wide tire on a narrow rim, you risk sidewall or rim failure. This combination causes very sloppy handling at low speeds. Unfortunately, current mountain-bike fashion pushes the edge of this. In the interest of weight saving, most current mountain bikes have excessively narrow rims. Such narrow rims work very poorly with wide tires, unless the tires are overinflated...but that defeats the purpose of wide tires, and puts undue stress on the rim sidewalls.
Georg Boeger has kindly provided a chart showing recommended width combinations:

Edit: Chart didn't transfer -oops!

lots of folks err on the side of caution, but the truth is your can run them as big as you can fit. mountain bikes do this all the time. just know that you won't be cornering hard.