Just 0,1" - 18"x1,25 (Kojak) to 18"x1,35 (Innova, Schwalbe Marathon Racer) to show the difference in technical data!
But a big difference makes the profile…which Kojak’s don’t have 
.
Additionally are the Kojak’s much harder due to the tyre pressure and less comfortable.
Pressure Innova, Marathon Racer : 6,0- 6,5 bar
Pressure Kojak : 8,0 bar
I don’t really know, I try to avoid such things…
Maybe switching to 16" and special tyres (only available for 16") -
see here a post of the snow riders:
[url]Photos of Stridas in Hong Kong]
No. Even with original mudguards no problem.
No need of new rims.
Please try your local google search i.e. EAN-Code: 4026495473668 for the Schwalbe.
As said, the Innova’s are from G.U.M. directly.
So, you’re from Finland, maybe you know “Korpiklaani” ?