Originally Posted by
Mulberry20
The prior two posts are proof positive you should take internet advice with a grain of salt.
There is no way in hell you can or should run 28 tires on wheels of that era and width.
They will not seat properly even if they can be mounted at all.
The fact it is a 3 mm difference is totally irrelevant. A 28 mm tire will likely size 29 or 30 nowadays.
I am a mechanical engineer I should know.
That sounds alot like one of our government officias that claimed he could read and understand scientific medical papers becuase he had a PhD in social sciences
In my experience Continental's road tires actually size smaller than their stated size. And that comes from riding a lot of Continental tires.
The Mavic Open Pro rims that Bianchi used on some of their bikes in 1999 would take tires sizes from 19-28 mm. I'm not sure why one of their less expensive bikes would have a narrower rim. Mavic CPX 21 rims used on their more expensive bikes also are capable of using 19-28 mm tires.
Scroll to the chart at the bottom of the page, and you might see some data from someone who actually knows about bikes.
https://www.sheldonbrown.com/tire-sizing.html
This is a good site if you want the specs on older bikes:
https://www.bikepedia.com/Quickbike/Bikes.aspx