Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > Tyres > contact patches at full lean.................

[dickieducati]

someone will know this i'm sure...................

does a 190/55 on a 6 inch rim give more contact patch at full lean than a 180/55 on a 5.5 inch.

i think it does but not sure???

[Rattler]

I reckon its the same!!!

[Felix]

If could actually notice the difference, you'd already know!

[weeveetwin]

My two-pennorth..
Because of the greater radius of the 190/55, I reckon you'd have more area in contact with the track/road - but less 'ground pressure' per sq mm because the bike's weight is more widely spread. (so on a wet/slippery surface you'd actually have less grip).

I could well be wrong though! One for Shazzam I think..

[dickieducati]

yes i await an essay at some stage, although i'm kind of with your thinking.

[David Cook]

My 996SPS came with a 5.5"/190 rear setup which was changed to a 180 for all the "advertised" advantages. I then changed to mags and had a 6" rear but maintained a 180 tyre.

I've now got a 190 (D208RR) for Catalunya in October, having been convinced by Dunlops Sales Manager that the benefits are noticeable.

[Harv748]

Having just bought a bike with what looks like a 6in mag rear, fitted with 180 (BT0012ss (?))...why does the tyre in general look wider and flatter than my 748 fitted with standard rear wheel and a 180 (pirelli diablo)?

Does the slightly wider wheel flatten the profile of the 180 tyre, or is the difference I can visually see due to the diference in tyre profiles from make to make?

Does that make any sense at all?!?!?

[dickieducati]

pretty much answered your own question. it should have a 190 on if its a 6inch rim, the profile (as you correctly noticed) will be flatter as the tyre is being widened out. pop a 190/55 on and it should turn in better.

[Harv748]

Well, thats what I thought...but then why do people stick a 180 tyre on a 6 inch rim to quicken the steering, if, as you suggest, it flattens out due to the wider rim???

[dickieducati]

standard rims on a ducati are 5.5 inch