Ok, here it is, I couldnt wait until tomorrow to put them on.
I think this tyres are a deal changer when it comes to 451 20", no longer are we the laughing stock of wheel sizes! 406 have had the awesome kojak's for a while, the Ultremo ZX are Schwalbe's best racing tyre, from their website:
As tyre designers the Ultremo is the pinnacle of our ambition. We strived relentlessly to increase its speed and installed the ZX with HD Speed Guard and RaceStar Triple Compound. Both components are perfectly tuned to the requirements of an outstanding competition yre. The result: Significant reduction in rolling resistance. Even so we used additional material to reinforce the tyre shoulders and to ensure a considerable increase in mileage. ZX - the best Ultremo ever!
Easy, they go as easily in as the Durano, I changed it without the need of any tools, Schwalbe didnt have any 451 20x0.90 tubes so I used the ones I had on:
Pic of tubes:
Got a little excited when pumping feared for the tubes so brought it down to 120psi
Pumped and on the bike
View from the top, slightly narrower than Durano
Finally a GREAT tire for 451, I am definitely retiring my carbon full size racer now
But the proof is on the road, taking it tomorrow morning for a ride!