Why do some bike manufacturers fit a smaller or larger cassette compared to others? Why do they fit a certain make of finishing components? A large part of it depends on what they can buy at the best price and has the best availability.
I am not sure that would apply to tyre size. Brand/quality perhaps, but on a (I'm guessing) racy bike I feel the manufacturer would put the tyre size on they feel goes best with the bike.
DKay wrote:I find your question about larger and larger tyres pretty obvious and I think you know it is too. Of course, if you fit huge tyres, then you're going to run into deminishing returns. But 25mm is a great compromise between extra comfort without reducing your speed.
'Compromise' is the key word there. The Propel sounds like a bit of a no compromise frame/bike for which 25mm tyres will be a bit of a compromise.
To me 25mm are not a magic wonder size. They may well offer a great mix of speed and comfort for a lot of people on a lot of bikes, but there comes a point where its just a bit silly IMO.
I will never believe that the same tyre in 25mm at say 90psi is as fast as a 23mm/100psi one.
Nothing wrong with wanting it for comfort but don't pretend that there is no performance difference between 23-25 with different pressures, but weirdly is between 25-28.
I do not care how minimal the difference is either.
If you wanted to run 23mm most of the time but wanted the option of 25mm for certain rides then fair enough, but if its to have full time 25mm then just get a different bike if its not designed for the bigger tyre.