Many people say Tontis run much better on 110/90 rear tyre but the Bridgestone website says different:
http://www.bridgestone.co.uk/motorcycle-tyres/tyre-catalog/search-by-vehicle/
comments?
Kate??
What bike?
My MKIII le Mans ran better with Conti’s or BT45’s than Avons because the tyrses are slightly narrower. a friend reckoned I was 10 mph quicker through the bendy bits.
This was 110/90.
Someone on here bought a MK11with 120/90 and junked them almost immediately.
The cynic in me sez it’s just sales blurb to sell the tyre.
plus 1 for the 110, bought a Spada with a 120 once, although the tyre just cleared the swinging arm, it felt cumbersome through the twisties, replaced with a 110 Avon, the magic came back.
Yep. Me too. 110 all the way. I have 110 Avons on both of mine and i think they are great. To be fair I havn’t tried anything different,
but if it ain’t broke…
It’s all down to personal preferences but I found BT45’s much better than Avon’s.
+1 for personal preference,
I’ve tried the 100 front 110 rear combo and the 110 front 120 rear combo and like the slightly fatter set up the best 
I have 110 and 120 on my Eldorado. It came that way. It won’t be long before I have to change the tyres, but don’t know which way to go!
We run same size front and rear on our loops jmee…120s…and at about 25 pounds pressure…
On tontis I prefer110s on the rear…tho I think avon do an inbetween size…I remember putting a 120 on the back of my blue Mk 2 many years ago and it made it weave…phantoms we all seemed to use then…
Are those your Maxxis white walls Kate? I’m not sure, without a trip to the shed, what my tyres are. They were on it when it came from America. I have been running my pressures at about 35. It feels a trifle unstable on corners when they pressures get too low.
110/120 Pirelli Demon Sport work for me. 33/35 psi. Some say Avons start to go off when half worn. I bought mine with half worn Avons and they had a tendency to track every line on the road.
Having used Demons myself, if you measure them they might actually measure as 100 / 110, previously I had Avon something or other can’t remember, the front one measured a true actual 100 and was rubbing the mudguard (plastic LM - Spada style) so had to sand a bit off of each side. The mudguard that is. I concluded that hitherto, a “100” usually turned out to be 90 in practice.