ST1100 Tire Size Issue

Cheesehead · Mar 4, 2017

Greetings ST Owners Across the Land-

After years of BMW ownership, I am now a proud owner of a low mileage 2000 ST1100, non-ABS. After years of anticipation of ST ownership, I cannot wait for the weather to improve here in Cheeseland for my maiden voyage..

My bike had a meticulous previous owner, and is in excellent condition. He had also purchase tires for the bike just a couple of months ago that were still wrapped as new, and they were included in the deal.

The tires are Metzler Roadtec Z6s, the front being a 110-80 ZR 18, which according to the owners manual is the correct size for the bike. The new rear tire is also a Roadtec Z6, the size being 170-60 ZR 17.

According to the owners manual, the correct rear tire size is 160-70, not 170/60. Thinking that perhaps the previous owner had erroneously purchase the wrong size, I checked the rear tire size currently on the bike. It is also a 170-60. Not sure why this size tire was mounted, but I further noted that in the owners manual, the previous owner crossed out the size listed (160-70) and wrote down 170-60.

So...it appears the previous owner was purchasing this size on purpose, and I am wondering if there is a reason this may have been done. As I mentioned above, he was very meticulous about service work, and all other details are according to the book.

Anyone have an idea why he may have been using this size? Has anyone else run this size with this tire and have any feedback?

One last question.. I remember reading somewhere in this forum the method used to determine when the Metzler tire was manufactured. The tires have a code of 3015 for the rear, and 3715 for the front. Am I correct to assume the rear was manufactured during the 30th week of 2015, and the front during the 37th week of 2015?

Thank you all so much for the feedback..!!!

Cheese..

Bush · Mar 4, 2017

Cheesehead said:
Greetings ST Owners Across the Land-

After years of BMW ownership, I am now a proud owner of a low mileage 2000 ST1100, non-ABS. After years of anticipation of ST ownership, I cannot wait for the weather to improve here in Cheeseland for my maiden voyage..

My bike had a meticulous previous owner, and is in excellent condition. He had also purchase tires for the bike just a couple of months ago that were still wrapped as new, and they were included in the deal.

The tires are Metzler Roadtec Z6s, the front being a 110-80 ZR 18, which according to the owners manual is the correct size for the bike. The new rear tire is also a Roadtec Z6, the size being 170-60 ZR 17.

According to the owners manual, the correct rear tire size is 160-70, not 170/60. Thinking that perhaps the previous owner had erroneously purchase the wrong size, I checked the rear tire size currently on the bike. It is also a 170-60. Not sure why this size tire was mounted, but I further noted that in the owners manual, the previous owner crossed out the size listed (160-70) and wrote down 170-60.

So...it appears the previous owner was purchasing this size on purpose, and I am wondering if there is a reason this may have been done. As I mentioned above, he was very meticulous about service work, and all other details are according to the book.

Anyone have an idea why he may have been using this size? Has anyone else run this size with this tire and have any feedback?

One last question.. I remember reading somewhere in this forum the method used to determine when the Metzler tire was manufactured. The tires have a code of 3015 for the rear, and 3715 for the front. Am I correct to assume the rear was manufactured during the 30th week of 2015, and the front during the 37th week of 2015?

Thank you all so much for the feedback..!!!

Cheese..

Not sure why the guy would use the 170/60 when the 160/70 is still available. Possibly it was out of stock and he bought the nearest size to keep the front and rear same branded. The 170/60 is a little wider and a little lower profile tire, which will work fine on the 1100, but it will make your bike stand up a little higher on the side stand, so you might need to be a bit more choosy on the surface angles you park on.

Conversely, on the front, if you can't get the 110/80, you can use the 120/70 size, but it will cause your speedo to read a few mph faster than actual.

Tire codes indicate week and year of manufacture, so your 3015 rear tire was made in the 30th week of 2015. I personally like the Z6 a lot and have run several sets on two 1100's over 21 years.

One other tip for you, since you have two new Metzelers to mount. The red dot on the sidewall indicates the lightest point on the tire, as determined by the factory. That red dot should be mounted at the location of the wheel valve stem.

George · Mar 4, 2017

Cheesehead, I've used both 170/60 and 160/60 but much preferred160/70 for both handling and longevity.

Uncle Phil · Mar 4, 2017

I use both sizes, depending on the brand of tires. If I can get the 'correct' size in the brand I want, I use it. If not, I use the 170/60 even on my ABSII ST1100s without any problems at all. BTW, the 170/60 is the size used on the rear of ST1300s, and the front for an ABSII (120 width) is the same size as the ST1300 front.

dwalby · Mar 4, 2017

you'll find both the 110/80-18 and the 160/70-17 to be uncommon sizes. Even with lots of motorcycle shops in my area, I always have to order them, nobody has them in stock. The 120/70-18 and 170/60-17 are much more common sizes, but I've never tried either because I didn't want to deal with potential clearance issues. Others here have made those sizes work, but from experience I've found in the past that different brands/models of tires with the same nominal size stamped on the sidewall will have slight variations in their actual dimensions, so one brand/model may clear the swingarm, and another may not.

ST Gui · Mar 4, 2017

At first I thought the PO might want to lower the ride height but 10mm? doesn't seem like enough of a gain (or loss) to matter.

ad1993pan · Mar 6, 2017

Cheesehead

There is a guy in Holland who put the Pilot Road 4 GT on his ST1100 with the size that is used under the ST1300
There should be room enough for the front and rear tire.
He is very happy he chose the Michelins on his bike, it drives normaly good, but now it steers and drives even better.

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Uncle Phil · Mar 6, 2017

The only ST1300 size rear that has a clearance problem that I'm aware of is one of the Shinkos. I've already ran the ST1300 BT030GT, the PR3s, and the Angel Pirelli GTs without a hitch.

dwalby · Mar 6, 2017

the main reason I've never tried non-stock sizes is all the places I've bought tires from had the policy "once its mounted, its yours, no returns". So if it didn't fit right, you ate it. Are there any Internet sellers that will take a tire back if you mount it, but never run it on the road?

Uncle Phil · Mar 6, 2017

dwalby said:
the main reason I've never tried non-stock sizes is all the places I've bought tires from had the policy "once its mounted, its yours, no returns". So if it didn't fit right, you ate it. Are there any Internet sellers that will take a tire back if you mount it, but never run it on the road?

I would be surprised if they did. If I have a tire question, I just ask those who have actually done that particular tire brand and size. I may try the PR4s next after I burn another set of the Pirelli Angel GTs. I was bit underwhelmed by the mileage I got on the PR3s I tried.

ST1100 Tire Size Issue

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