Michelin Pilot Road 3 Front Tire - 120/70ZR18 on ST1100?

Joined
Apr 8, 2017
Messages
174
Location
Utah
Bike
1994 ST1100
STOC #
9042
Can't seem to find the 110/80ZR18 Pilot road 3 any more. Anyone ran a Michelin Pilot Road 3 Front Tire - 120/70ZR18 on an ST1100? Will they fit?
 
Disregard. Did some more searching and found some guys are running them, so they must fit ok.
 
I have used that size front tire on my 1100 Standard a few times with no problem.
did it have any noticeable affect on the front ride height? I know tire sizes aren't exactly consistent from brand to brand, but I'm curious if 120/70 is typically lower/higher/same profile as 110/80 in the same brand/model tire.
 
did it have any noticeable affect on the front ride height? I know tire sizes aren't exactly consistent from brand to brand, but I'm curious if 120/70 is typically lower/higher/same profile as 110/80 in the same brand/model tire.

These were Metzeler Z6 Roadtec fronts and they had no noticeable effect on ride height to me. The height difference is minimal, but it did cause the speedo to be closer to actual speed, rather than reading about 7 kph less than actual with a 110/80.
 
These were Metzeler Z6 Roadtec fronts and they had no noticeable effect on ride height to me. The height difference is minimal, but it did cause the speedo to be closer to actual speed, rather than reading about 7 kph less than actual with a 110/80.
there seems to be a unanimous opinion that the ST1100 speedo reads high with the 110/80, so I'm guessing you meant that the 120/70 was a bit taller so the speedo slowed down to be closer to actual. Or are the Canadian models different, and the speedo actually reads a bit slower than actual with the stock tire??
 
If it's a post-1995 abs model, the 120 is the right size. Those have larger forks and wider wheels. I'd hesitate putting a 120 on the wheel meant for the 110, as it is a half-inch narrower.
 
there seems to be a unanimous opinion that the ST1100 speedo reads high with the 110/80, so I'm guessing you meant that the 120/70 was a bit taller so the speedo slowed down to be closer to actual. Or are the Canadian models different, and the speedo actually reads a bit slower than actual with the stock tire??

Yeah, you are right there. I got it bass ackwards. Been a while since I used a 120. As to Don's comment, whether an ABS model, or not - mine is non ABS - the 120 works fine. Had at least three of them, without looking up the records.
 
I put a ABSII front rim on my 97 standard (just had to swap the discs) and it works fine (so I'd have the same rim size on all three ST1100s). All the ST1100 front rims will swap and have clearance (I've actually done it just to see). The standard discs are larger in diameter than the ABSII discs, which is why you have to swap them but everything else matches up. Several ST1100 riders have put a 120 (same size as the ST1300 front) on 110 rims as Bush has and their hair did not catch on fire from any reports I've seen nor did they crash and turn into a raging fireball ... :biggrin: Why, I even run 170/60s on the rear (the ST1300 size) and they work fine.
 
If it's a post-1995 abs model, the 120 is the right size. Those have larger forks and wider wheels. I'd hesitate putting a 120 on the wheel meant for the 110, as it is a half-inch narrower.
ran both sizes on my 97 including 4.5 k trips with no issues. In fact I ran a 130/70-zr18 Bridgestone Max with I liked but it didn't like tar snakes. It was matched with a 190/60 zr 17 Avon on the rear that lasted 15k:banr1:
 
This calculator will show you the exact the differences between two tire sizes such as a 110/80 vrs 120/70.
https://www.tacomaworld.com/tirecalc?tires=120-70r18-110-80r18
"exact" is a relative term here. In my experience different tires with the same nominal size on the sidewall will all run a little different dimensionally, so that calculator isn't going to be "exact", but probably good enough for estimation purposes. Years ago I kept a list of measurements I'd made on various tires on a whiteboard in my garage, but eventually lost interest and erased the info because many of the tires were no longer available anyway. I want to say on a nominal circumference of about 2000mm on a rear tire there was maybe a 50mm range between the smallest and largest circumference for the same size tire, different brands and models, so an exact measurement wasn't really practical for any given size.
 
"exact" is a relative term here. In my experience different tires with the same nominal size on the sidewall will all run a little different dimensionally, so that calculator isn't going to be "exact".
Sheesh, I didn't mean "exact" as in absolutely perfectly microscopically precise. Just meant that someone could maybe get an idea of how a 110/80 tire would compare to a 120/70 tire or any tire for that matter, so they could maybe figure out if it might fit or not. Stuff like this is "exactly" why I hesitate to post anything in forums.
 
Sheesh, I didn't mean "exact" as in absolutely perfectly microscopically precise. Just meant that someone could maybe get an idea of how a 110/80 tire would compare to a 120/70 tire or any tire for that matter, so they could maybe figure out if it might fit or not. Stuff like this is "exactly" why I hesitate to post anything in forums.
You linked a tool that provides circumference measurements with 0.01mm resolution, and used the term "exact" in your post, so I was simply providing real-world input that the tool is orders of magnitude more precise than the actual tires will be, so don't take it too literally. If you meant to say that the tool is only sufficient so that someone could get a basic idea of how two tires compare, then you should have said that, and your message would have been much clearer.
 
Sheesh, I didn't mean "exact" as in absolutely perfectly microscopically precise. Just meant that someone could maybe get an idea of how a 110/80 tire would compare to a 120/70 tire or any tire for that matter, so they could maybe figure out if it might fit or not. Stuff like this is "exactly" why I hesitate to post anything in forums.
nobody read the fine print....plus or minus 5
 
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