chain wheel clearence?

[HowardQ]

People have already covered most of this, standard tyre on a Falco is a 180, Mille uses a 190 on the same width wheel, so the Falco rim size will take the 190 no problem there.
A 190 will leave it pretty close to the chain and as has been mentioned there are various true tyre widths for different types of 190 tyres so if you have one of the "wider" ones you OK on a 180, so why change it? Most people have spent some time raising the rear ride height to get better turn in, so I would stick with the 180 if you can.
Obviously now you have bought a 190 you may want to keep it for now, so one other major issue to be aware of. My ZX-9R has a standard 190 rear tyre and is also very close to the chain. I did not realise how close until I gave the chain a good clean and lube after the winter crap. First time I rode it after that I seemed to be losing grip and all over the place on left hand bends. Checked when I got it back and the fresh chain lube was all over the LH side of the tyre. NOT nice!
Difficult to stop this when the tyre is running this close to the chain. I would suggest you go for dry Ceramic chain lube or fit extra crash bobbins on the LH side of the bike!

[Nooj]

Never ever trust the markers on the swingarm. I don't know if it's true for Aprilias, but on a lot of bikes those marks are stamped onto the individual parts before the swingarm is assembled, this means any variation in the welding or bending during assembly will throw the marks out of place. They are there to be a very rough guide only.

I'm currently running a 190/50 Mez6 which clears the chain OK. The Milles and Tuonos all run 190 tyres, and they have the same wheels, engines and swingarm dimensions as the Falco, so there's no reason I can think of that a 190 wouldn't work on a Falco as well.

[anzacinexile]

What he said...........

I use a laser between the sprockets on all me bikes and you'd be amazed how far out the markings are out on every bike

[joecrx]

good tips ther , i always use the guid marke in the swing arm , but going to try the 8 foot tube methed to see if they read correct , only cause i have one in the garage it dosent work but now i can put it to good use