Originally Posted by
PeteHski
You just need to read current trusted sources of info and look at the spec of current £10k cutting edge race bikes.
Another clue is that the latest generation of aero wheels are often optimised around wider tyres - usually 28 mm.
Your new race bike came with wider tyres as a reflection of what the pros are now riding. I’m pretty sure they are not trying to make their bikes slower.
25 mm tires are still used – see for example Canyon Ultimate CFR DI2, 10+ KEUR, with 6.3 kg weight. I think 28mm is overall better in aero setups (expensive aero wheels). But when producers force you to buy 28mm tires on common aluminum wheels, the losses from lower aerodynamics and higher weight might be bigger than gains in rolling resistance.
The same applies to weight increase: The very expensive bikes compensated for the extra weight of disk brakes and electronic group set by reducing weight elsewhere. But for lower tier bikes, this extra weight was only added to the bike.
The above might explain why a very expensive bike (say a “pro bike”) might perform today marginally better than its older equivalent, whilst a lower tier bike (say “casual rider bike”) performs today lower than its older (skinnier and lighter) equivalent.