Tire size
 

I bought a bike used with good 700c-23 tires on it. IN looking over old brochures, the original specs for the bike indicate 700c-28 tires were used. Should I replace them with the "correct" size or not? How does diameter affect ride quality, performance, handling, etc?

Thanks

23mm tire is good for almost any weight of rider but is considered harsh when
pumped up above about 110#. Larger tires tend to be more absorbing of road
shock, and can handle clydesdale weights with aplomb. 28 is a comfy ride and
does nicely at 80-90#. 28mm will fit between most road brakes with a bit of
a shove. Larger tires need cantis and a cable release to fit or you deflate the
tire to fit. Rim suitable for 28 can prolly handle a 32, though the frame might
be a problem if tight, but most frames oemed with 28 have relaxed dimensions.
You will coast a bit slower and have to put a few more watts into a larger tire
for the same speed but if the tread is smooth this is a minor consideration.

What is originally spec'ed on the bike is irrelevant. Your wheels/frame was designed to accept a range of tire sizes. Tyre sizes differ based on the purpose it's used for, total weight and road conditions. Wider tyre at lower pressures will be more comfortable over rougher roads. On glass smooth roads the narrowest tyres pumped up to high pressure will be faster, and also more aerodynamic, and lighter.

You can run the 23's on the rims you have - as that's how it came from the previous owner. 700 X 28C is a pretty standard size to put on a retail bicycle. Sort of middle-of-the-road width. So they don't scare prospective customers with these "how do you ride on those tiny tires??" So you can keep the 23's - or you can go to 25, to 28, maybe to 32. It's up to you to find what would work best for your terrain and riding-style.

Happy Tire-Tracks!

There are no standard bike tire widths. Tire width should be based upon the type of riding you do and the weight of the rider. A 215 lb rider can't ride the same width tire a 150 lb can ride. Unfortunately most road bikes come with 23 tires assuming everyone weighs the same? The tires you put on should be based upon the type of riding you do, off road, trails, road, how rough are the roads, and your weight.

Tire manufacturers design their tires for a 15% tire drop. You need to use the tire that will give you a 15% tire drop. Contrary to popular opinion, a high pressure tire is not faster than a "normal" pressure tire. High pressure tires are only faster on tracks.

Wtf. This is complete nonsense. The only thing a 215lb rider will have to do to ride the same tyre is put more air in it to prevent the extra weight from becoming a factor in pinch flats.

15% tire drop? Wtf does that even mean?

Assuming riding on glass roads, a higher pressure, narrower tyre will always be faster. There's a point on *real* roads where going to higher pressure/narrower results in being slower but that point is different for everyone. It depends on the road the and combined rider weight & bike.

I think you're confused.