Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > Tyres > Tyre Sizes

[duc749s]

Just thought I'd pass on a bit of information that I recently aquired!
I was chatting to a guy from Dunlop a couple of days ago & I asked about the benefits of changing from a 190 to 180 or vice versa. His reply was interesting!
He was adamant that people would be VERY unwise to change from the manufacturers specification. He warned that fitting an "Incorrect" tyre size would alter the intended profile of the tyre. Also, by changing from a 190 to a 180 you are in danger of riding off the edge of the tyre way before you would expect to be at maximum lean.
Just a thought for you all...
Any thoughts/comments?

[dickieducati]

he's absolutely correct;

the point being, the 190 tyre is NOT the correct fitment for the 5.5 inch rim on ducati's. 180 is the correct fitment. the 190 was only put on for cosmetic reasons; ie the fatter tyre looks better.

a 190 is correct fitment on a 6 inch rim.

[Loz]

I'm pretty sure that warranty and/or insurance issues make swapping to a 180 unwise.
For myself, call me chicken, but I prefer the feel of road-rubber to side-wall, every time!
Seriously, I'm no expert, but there must be better ways of quicking the steering - using the adjustable steering head angle, track alignment or good old fashioned upping the rear-shock pre-load.
(I fully expect to be corrected in no uncertain terms here!)

[Glyn]

just had a look in my st2 handbook and my st2 rear is a 170 60 17 it also lists the st4 as 180 55 17
the rear wheel dimensions are also listed 5.5 x 17 for both the st2 and st4

so for the same size wheel ducati list different tyre sizes as standard fit depending on the model ?

as i was thinking of changing the rear soon i might go for a 180 this time. i understand that this will slow the steering a bit, but what are the advantages of going for the wider tyre apart from the look. does it accually give a bike any more lean angle in the real world .

[Shazaam!]

Some tyre profiles are more sensitive to rim width than others. Dunlop, for example, says that their 180 slick works fine with up to a 6.25 inch wide rim. In the past, both Michelin and Dunlop have stated that a 5.5 inch wheel is suitable for 160 through 180 tyre widths. Different tyre manufacturers specify different rim widths for their tyres.

From a warranty/insurance viewpoint, I can only offer that in the 1995 916 owner's manual, Ducati specified the 180/55 as an "alternative" to the 190/50. Also, the bike's under-seat specification sticker also listed both sizes as recommended.

[Edited on 5-10-2004 by Shazaam!]

[bazzer sps]

Also why do Ducati fit a 180 on 749's if they are not ok?

[Mike Davis]

Mr Norford, you are indeed wise to go the 180 route, we fit a lot to early ZX6`s and ST`s and the riders all comment on the improved handling, same goes for 190 dropping to a 180 (there are a couple of bikes this is impractical on).

The tyre manufacturers will always tell you to stick with standard fitment: A. to stop any law suits etc and B. 190 are generally more expensive than a 180.

If a 190 is so good why do all club racers drop to a 180 and those we fit to road bikes all comment on the better stability of the bike in faster turns.

[uncledunnie]

180 supercorsa on the rear of my 999 - very very happy with the change from the original 190. Try it - it works.

[bradders]

havent riden on 190, as mine was fitted with 180. Noticed from Cads that I did seem to be right on, or over, the edge of wear when I returned to paddock. I am sure I had loads to go before disaster but it makes you think - how far can a 180 go? Also, Nick had a 190 and has strips on the sides, and we all saw how quick he was thru the bends and his pics demonstrate serious lean angle.

[Dukerob]

I've used 180 and 190, I remember switching to the 180 and finding the steering just seemed more consistent on direction changes. We swapped tyres Fri lunch from 180 am to 190 pm and there was a difference going from left to right or vice versa. Like a slight reluctance when you hit upright ? Not sure it was worse, just different. I think Dickie, Mike et al are right that the 180 is the right size for the 5.5in rim so Nelly tells me, but I also think you get a bigggggger contact patch with 190 although could be wrong ? Usual applies imo, use whatever you prefer and enjoy riding on, the 190 was a cheap part-worn so thats what sorted it for me this time !!