Hi, I have a brand new set of Ultegra RS500 wheels and am looking to fit some nice tyres to them. I have good clearance which which will accomadate upto a 28mm tyre.
I have previously ran Vittoria Rubino Pro Graphene 25mm, Vittoria Open pave CG 27mm and Vittoria Corsa G+ 28mm.
I find the 28mm corsa just don’t perform as my 25s used to in a shimano 15c internal width rim. I think the 25mm size performs better in that size rim but this depends on the manufacturers sizing.
I was set to get some continental GP5000 on a 25mm but I hear they size up small which would mean going for a 28mm which potentially could be slightly big in a 15c internal width rim giving the light bulb profile similar to that I already have although this could also be enhanced due to the thin cotton sidewalls expanding more?
Any suggestions on tyres for good all round use, road miles. I used to also use continental grand sport which I generally found a good tyre, reasonable comfort but good value and long term endurance.

I quite like the Donnelly / Clement LGG, roles well, good grip. Mrs Kilo has 25mm open pave on her road bikes, great tyre.

What do you mean by performance?

I can’t imagine a couple of mm of lightbulb is going to matter, or that cotton expands more.

Huh, good question actually, I’ve just replaced some 20mm internal DT wheels with the same Ultegra wheels, guess I’m going to find out soon enough!

One thing I’d say is that my first impressions of the 20mm internal DT wheels when I fitted them 3 years ago was that the tyre felt less compliant, rather than more. Took a bit of fiddling with tubes, pressures and seatpost to figure it out.

Also my summer bike has 17mm internal Fulcrums, and I can honestly say I’ve never noticed a difference switching between bikes (both aluminium frames, arguably the summer bike might be more compliant as it has noticebaly skinnier stays, plus summer bike has nicer tyres). I suspect you’ll notice a slight difference initially but adjust pretty quickly. personally I’d just concentrate on fitting the widest tyre I could in there and being done with it, wasn’t long ago we were running 2.3″ MTB tyres tubeless on 17mm internal rims…

All I can say is that my GP4000S in 25c is quite a bit bigger than my 25c rear tyre (can’t remember the exact model but it’s the Conti black chilli one with more puncture protection).

I’m having similar issues with sizing where I want bigger tyres but they’re not created equal.

I have recently fitted some of the older version vittoria rubino pro 3 tyres in a 28mm on the same size shimano rims and they just seem to seat better and hold shape better. I have used vittoria corsa in a 25c and they seemed to feel better. By perform just the comfort level with the narrower rim. I understand the 28 allows to be run at run at lower pressures with the same sort of efficiency but I don’t find the comfort as good as I had hoped considering the lower pressure as I have a pretty stiff race frame which can feel harsh.
I have considered looking at alternative clincher wheels but I heard the RS500 are a decent offering as solid training wheels. Having used some newer shimano wheels with a 17c internal I think the tyres seat better with a wider and lower profile, its fine margins but the 28 corsa in my 15c sit higher and narrower as you would expect but they do bulge out a lot at the side. The tread is almost glued over, its a pretty unusual tyre compared to many of the one piece type offerings in that regard which is why I was looking at going back to Conti or other alternatives for this set up.