Advice on buying first vintage road bike?

[bikeworkshop]

If you're not looking for 25s, you won't want them. it will cost you confidence at speed.

Grip on corners and braking is massively reduced over 32s, and it turns out the benefit of air- and rolling resistance, lighter weight are way smaller than the disadvantages.

Pros are faster now on 32s than they were on 19s.

I've got several lovely bikes only take narrow tyres, I love them, but not in fast descents or corners.

Trouble is, beautiful vintage racers, 28 is huuuuuge!

 

[hamster]

25mm is fine, so is 23mm. 20mm gets a bit lumpy on UK tarmac (the stone size is specified larger than most countries in continental Europe).
I think all you will find with older hoods is that they are narrower and smaller. Older bikes tend to have a bit more spring in the forks which takes out more sting than modern forks (especially disc forks which have to be overbuilt for braking loads).

That said, I agree with @bikeworkshop that modern tyre construction is so good that fatter tyres have no resistance penalty over narrower. I sold my 23C (max) Litespeed and kept my 1980 Witcomb which can run all the way up to 32C. It had no speed penalty over mixed country, although 1.7kg heavier - all due to the fatter tyres.
Personally 23C is fine for grip. The contact patch is the same size (basic physics) for any given tyre pressure - BUT you can indeed enlarge it by running softer.

 

[Swelo]

Hmmm, less confidence at speed and in corners doesn’t sound too appealing when gears enable more climbing; what goes up must come down. I want skinny tubes, not skinny tires! It’s kind of heartbreaking to see how many lovely frames are hamstrung by tight tire clearances.

 

[bikeworkshop]

A high quality lightweight 28 though (Ditch the guards, ride something else in the rain) run at 70psi (ride carefully, avoid potholes) will give you quite a lot of grip.
This opens up quite a few nice vintage bikes.
A lot of riders use vintage stronglight or ta cranks to get a wide range like 34/50, but you can easily go further if you don't mind losing "the look"

 

[non-fixie]

As it happens, I have ridden the bike I posted above for quite a bit with 28mm Paselas as well, and the main difference I found is that, while it already was a responsive bike that handled quite well, it now feels even more like a precision instrument.

As always, YMMV.

This is how it looked previously, during a tour in Tuscany:



I like the look and simplicity of downtube shifters, and have them on many bikes, but I do find myself shifting more often when riding with brifters.

 

[grantoury]

Lovely looking bicycle really. Well made. A 28mm tyre will be fine and does all roads perfectly. As it is the mudguards fit so I have no doubt a 28 will too. (Without mudguards) 500 euros is a bit steep. 400 max because it looks in beautiful condition is what I would pay for this.

 

[dirttorpedo]

My advice is to know your size in the period of bike you are looking at - british style bikes of the 70's and early 80's fit differently than modern bicycles or Italian style bikes of those earlier decades. I personally would target a "sport touring" or "touring" bike because they tend to have a more relaxed riding position, take fatter tires and have braze ons for bottles, racks and fenders. I would also target bikes that came stock with 700c wheels to make getting replacements / modernizing the drivetrain easier if desired.