Please note: I am not saying this is the best option, but I chose to fit a 180/60 as I couldn't get the correct tyre. I chose the Dunlop as I intended to fit a Dunlop front and wanted the same manufacturer front and rear.
Oh, and before I'm asked how it performs against the original Michelin, this is the Metzeler 160/70 that was fitted when I purchased the 906 - and it is the only Paso I have ridden.

Ok, so here is the D250 fitted to the 906 rim


The maximum width of the tyre is 183mm, and height is 615mm.
Here it is with the Dunlop 130/70ZR 16 Sportmax Qualifier - both viewed from the rear.
