Walt

I've never ridden a bike with Metzlers though I can tell you that new tires are always slicker than shit. I'd take it easy for a couple of days until you wear off the film coating that comes on all new tires. Avoid wet pavement/sand/manholes/big painted cross walks like the plague.

It would probably be best to go do slow figure 8's in an empty parking lot (Fair Lakes Mall is good - they clean up the oil spots regularly) somewhere to gradually wear the residue off. Better to look like an idiot in a parking lot than to head out on the road with new tires and the intention of taking it easy - only to find yourself in an "oh shit, turn HARD" situation.

New tires always turn easier than worn ones - the rubber in the center of the tire hasnt been worn away yet, providing a steeper angle. But, embiggening the rear tire will cause the bike to lean/turn slower. Ultimately, I predict your bike wont handle as well as it did with the smaller tires.

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Calmer than you are...