Rear tire size question for the group

[hotzuk]

First, happy holidays everyone. I have to shod my 2002 baby with new tires. I am thinking of going with the new pirelli angel st tires. Our current rear size tire is 170/60-ZR17. The manufacturer only makes 180/55-ZR17 and 190/50-ZR17. I still have the stock rims on my bike. Any idea on which tire I should put on the rear tire. Thanks for the advice gang.

[Airman]

First, happy holidays everyone. I have to shod my 2002 baby with new tires. I am thinking of going with the new pirelli angel st tires. Our current rear size tire is 170/60-ZR17. The manufacturer only makes 180/55-ZR17 and 190/50-ZR17. I still have the stock rims on my bike. Any idea on which tire I should put on the rear tire. Thanks for the advice gang.

And happy new year to you !

Your bike, like mine, (`03) has the 5" rear wheel. The proper tire is the 170, although the 180 is known to work. probably that tire is aimed at the sportbike market which is more likely to carry a 180/190 width. Somebody here is going to tell you about proper aspect ratio and the like, but I suspect it would affect performance very little. I would buy a 180 if someone gave me a smoking deal.

[TicTac50]

By installing 180/55/17 tire, you will increase the width of the tire by only 10mm from the original size and lower the rear of the bike by 3mm.
Going from 170 to 180 you will also be narrowing the gap between the rear tire and the housing of the drive shaft by 5mm.
Installing 190/50/17 tire will make the rear of the bike act real harsh and I think that R1150R does not have enough room between the tire and the housing of the drive shaft do so. You will need extra 10mm. Also 190 tire will not act properly on the wheel that designed for 170mm tire.
I personally like to stay with original size of the tire.
But if you really like to try something new, then go for it. I personally would not go higher than 180
I don't think that BMW dealer will do that, but independent tire place... maybe.
Good Luck.

[boxermania]

BMW recomends a 5 inch wide rim for the 170 size tire, as fitted on the R1150R. The 180 tire, as fitted on the Rockster is mounted on a 5.5 inch rim. The 170 tire has a diameter of 25.031 inches and the 180 has a diameter of 24.795 inches that amounts to a 1 mph slower speedometer reading at 60 mph (that is on top of the typical 5 mph slow reading speedo on our bikes)

The 180 size tire is easier to obtain than the 170 as it has, along with the 190 variant, become the industry firment standards.

That being said, personally, I wouldn't see any issues with the fitment of a 180 tire as a replacement to the 170 as any performance diference would be hard to quantify on the street.

[towerworker]

I currently have a 180 on the rear of my 04 R. Seems to do fine.

wayne

[garr2]

Just an observation!
I took the standard (170/60 ZR17) rear wheel/tyre off my 1150 RT this afternoon. After lifting it off its centering spigot it was a tight fit to roll it out through the narrowest part of the paralever/swing arm. If the tyre had been any wider I would have had to deflate it to squeeze it passed the paralever narrow point.

[towerworker]

I've experienced the same on my 04 R. But even with the 180 I have now on the rear I can still get the rear wheel/tire off the bike with just a little working it back and forth. I've not had to deflate the tire,

Wayne

[AirForceDirt]

The 170 tire has a diameter of 25.031 inches and the 180 has a diameter of 24.795 inches that amounts to a 1 mph slower speedometer reading at 60 mph (that is on top of the typical 5 mph slow reading speedo on our bikes)

This would be true if the speedo was affected by rear tire size. I don't know about non-abs R's, but mine is driven by my front wheel, so rear tire size won't change anything.



On another note, going to the wider, lower profile tire will change your turn-in and to a lesser degree tire flex. Remember, shorter sidewalls won't have as much room to absorb impact before damaging your rim, so dodge the bigger pot-holes.

Happy new year to you all.

[hotzuk]

Hey gang,

Thanks for all the great advice. I am sorry but I was really only looking at the 180 as the only viable option being able to go on the stock room. All of the advice is much appreciated. I now have to come up with the cash for the tires :-)

[towerworker]

I had no problem installing the 180 on my stock 5" rim. Even did it using just hand tools (tire irons). I've had no wear or handling issues at all. I bought the set of front and rear last year because of a tremendous price package. I would do it again.

Wayne