Upsizing Rear Tire to 190/55 (w/ pics)

[Top_Speed1]

No this is not a darksider move by any means, it's a real motorcycle tire

 

So in my experimental and inquisitive mind I was at my dealers about a month ago and was checking out a VMax getting a new 200/50 on the back. I was like wow, that's a nice "fatty" and the mechanic said "yeah it's the norm on a Max but you probably could upsize to it if you wanted". Got my wheels turning (pun intended) but noticed the rear arm (RH) pretty close already on my '09 FJR. I asked in this forum about going halfway to a 190 and got a response back from my bud Fred W. that it would probably be OK and got a "hey, at least it's not a square tire!" comment from him lol. I also read (& posted on a 190/50 thread) and found the 55 to be a bit taller (190x55). Got my wheels turning again! On highway speeds I think I'm winding way too many RIPS anyway, a little less would be good I was thinking!

So I purchased a new set of PR2's, front stayed the same 120/70ZR-17, the rear is now 10mm wider (190/55ZR-17) and about 1 to 1-1/2" taller. Visited my dealer (as I wanted them computer spun balanced vs. the less accurate static) and had the mechanic (Dave) pop them on ($138 for both OTB if anyone cares). Here's the rear just finished in his parking lot, looks pretty normal. The 10mm wider does not poke right out in this image but you surely can see the difference when the two tires were standing side by side (didn't get a pic of that, I'm a dumb azz!)

Whats your vector Victor? what's you clearance Clarence? (...from the whacked movie "Airport") Anyway I still have plenty of clearance, the right side is where the concern was but not anymore... could of gone for a 200!

As far as tallness goes as stated above, she now sits on the center stand with only 1/2" ground clearance (the image was taken at a slightly higher keel but in reality it's only a 1/2" and also goes up on center stand easier!

TO THE IMPORTANT STUFF-

I've been documenting the RPM (on the dream-o-meter) and MPH (GPS) and fuel mileage but there is not a whole lot there for owners who want the B-I-G difference, but there is a difference that is (slightly) noticeable. For instance on the RPM side I would be normally do a (GPS) 60mph and I would turn ~31-3200 RPM's, I now do it at ~3000 which makes total sense since the new tire is 5% larger in diameter (9900 vs 10450).

I've only put 2 tanks of fuel through so far so an estimated better mileage stat would be inaccurate. The gain I would expect should be very small and could only be estimated with many tank fills. That being said, even if I get just 1 more MPG I'm happy (however I'm thinking the highway 75+mph may be where I see the most mileage improvement). The main reason for this experiment was aesthetics anyway... I do like a mean n fat tire in the rear (but not crazy fat like some of the choppers have lol).

As far as feel goes, these PR2's are way way way way better than the pair of Bridgestones I had on as OEM tires. So as most new tires go, they are fantastic to say the least, a slight lean now has the bike now wanting to carve up a canyon road and it feels natural. I always had to put a slight steer (effort) and lean before to lay the bike over but not anymore. I can't give any cudos to the size changing on the rear for this, as some have mentioned it should work in reverse on this but I'm thinking more so on how crappy the Bridgestones were (which to be honest I just thought was natural for this bike). This 190/55 PR2 has a definite dramatic arch or curve (especially compared to my old Bridgy's 180/55 even when it was new 4K miles ago). This setup now naturally wants to dive and carve... holy shazitts! :yahoo:

So I'm VERY happy with this move. I think that I could of even done 200's and still maybe had a 'close to rub' clearance?. I'm sooo freeqn happy with the 190 but maybe with my next tire experiment I will try a 200, who knows, I'm just that crazy that I would try it . I don't do much riding in the rain so PR3's were not for my application/needs. These pics were taken just after the 35mile straight and flat ride home from the dealer so the edges are still vigin-a-sized as you can see.

As a footnote; The Beemer K1600GT/GTL that I'm currently courting has the exact same tire setup as my FJR (now) 120/70 and 190/55

 

[Auburn]

Can you put a bord across the top of the tire and measure to the ground so you can tell us the diameter of the tire mounted up? I might go this route since I ride 2up all the time.

 

[GeorgiaRoller]

Hmmm...I thought about putting a 190 on mine as well. I didn't consider the 55 sidewall height as an option. I may have to go this route next time I need a rear tire.

TFS!

 

[Top_Speed1]

Can you put a bord across the top of the tire and measure to the ground so you can tell us the diameter of the tire mounted up? I might go this route since I ride 2up all the time.

No problem I can do it this weekend and post a pic, the board across the top is just to mark the TDC and the starting point correct? Do you want it on center stand? (on kickstand the lean will mess things up a tad).

As tallness comparison, throw yours up on centerstand and measure the gap to the garage floor?

 

[Top_Speed1]

Got a message about me "wanting" to go to a 200. Well I'm happy with the 190 but if I get another hair up my azz I may "consider" it, doesn't mean "I want it" yet anyways lol. BTW the cost factor going up to these larger tires gets major multiplied with every step :dribble:

Here's a set of 200 fatty's on a Busa

 

[Auburn]

Can you put a bord across the top of the tire and measure to the ground so you can tell us the diameter of the tire mounted up? I might go this route since I ride 2up all the time.

No problem I can do it this weekend and post a pic, the board across the top is just to mark the TDC and the starting point correct? Do you want it on center stand? (on kickstand the lean will mess things up a tad).

As tallness comparison, throw yours up on centerstand and measure the gap to the garage floor?

center stand is fine as long as you tell us what the gap from the tire to the ground is.

 

[C&C]

Have you done any speedometer variance testing (since you have the GPS to check against). Maybe it's insignificant; I don't know.

 

[JasonB]

The height of the new tire can be calculated from the Aspect Ratio.

Old tire: 180/55

New: 190/55ZR-17

The aspect ratio New tire "55" indicates that this tire size's sidewall height (from rim to tread) is 55% of its section width "190mm". Old tire was 55% of 180mm.

.55*190 = 104.5

.55*180 = 99

104.5-99 = 5.5mm increase in height from tread to rim. X2 for total increase is 11mm => 0.433071in.

So just shy of a 1/2in increase in overall (un-sprung?) height.

 

[Top_Speed1]

Have you done any speedometer variance testing (since you have the GPS to check against). Maybe it's insignificant; I don't know.

Yes, I touched on it above, my speedo always has read 2 or 3 mph faster than what GPS stated. Yami is famous for this especailly in snowmobiling ("hey, my sled does 120!" Yeah OK, whada ya have? "Yamaha" oh yeah 120 alrighty then! lmao and hence the dream-o-meter comment we all have deemed them for). Yamaha has always thought of us Americans as easy to hog-wash and their idea of "Make em think they're going real fast and they will be happy!" ...yeah right, us tried-n-true powersport guys know all to well about their cheesy tactics.

GPS speed per RPM is where it's at here. It's minuscule but it's there none the less. In reality, the wheel/tire is now 5% larger in diameter. So we'll take the easy route here, same RPM to do 100mph for you; I would be doing 105mph. As said not that big of difference and this experiment was not intended for this but it is a nice little spiff however

 

[lnewlf]

Ho hum...benn running 190/55 ever since I got the FJR. Been flamed about the slower turn in [not noticeable,run a couple pounds more pressure]..As mentioned-rpm's are lower, mileage higher, looks better....All manufacturers list a 5.5 inch rim as acceptable fitment for a 190. A 200 is interesting but the tire is designed for a 6 inch rim and may be pinched so much that there would be no width gain. Hope someone tries it and posts up. Could always send the wheel out to Kosman and have it widened-we could maybe run a 240 [and it wouldn't be square..] Fat bottomed girls make the world go 'round..

 

[Top_Speed1]

Ho hum...benn running 190/55 ever since I got the FJR. Been flamed about the slower turn in [not noticeable,run a couple pounds more pressure]..As mentioned-rpm's are lower, mileage higher, looks better....All manufacturers list a 5.5 inch rim as acceptable fitment for a 190. A 200 is interesting but the tire is designed for a 6 inch rim and may be pinched so much that there would be no width gain. Hope someone tries it and posts up. Could always send the wheel out to Kosman and have it widened-we could maybe run a 240 [and it wouldn't be square..] Fat bottomed girls make the world go 'round..

Nice to know I'm not the only idiot out there :yahoo: ...maybe b/c were both from NY?

What lbs do you run the 190 at? Dealer pushed me out at 41

You guys can keep the fat bottom girls however! (and I believe it's "they make the rock'n world go round")

 

[fjrob1300]

So how about the term "Fatsider" eh eh??? When my car tire is due to be changed I think I'll look into this.

Rob

 

[DrWing]

As the old saying goes, if it works better for you and makes you happy then by all means. Other than a change in RPM going down the road, what's the actual footprint difference? I would tend to believe the stock size tire might turn alittle quicker. Cost vs benefits? Look forward to the feedback.

 

[mcatrophy]

Have you done any speedometer variance testing (since you have the GPS to check against). Maybe it's insignificant; I don't know.

Yes, I touched on it above, my speedo always has read 2 or 3 mph faster than what GPS stated. Yami is famous for this especailly in snowmobiling ("hey, my sled does 120!" Yeah OK, whada ya have? "Yamaha" oh yeah 120 alrighty then! lmao and hence the dream-o-meter comment we all have deemed them for). Yamaha has always thought of us Americans as easy to hog-wash and their idea of "Make em think they're going real fast and they will be happy!" ...yeah right, us tried-n-true powersport guys know all to well about their cheesy tactics.

GPS speed per RPM is where it's at here. It's minuscule but it's there none the less. In reality, the wheel/tire is now 5% larger in diameter. So we'll take the easy route here, same RPM to do 100mph for you; I would be doing 105mph. As said not that big of difference and this experiment was not intended for this but it is a nice little spiff however

Just for fun, if you want to play tunes on tyre sizes and how it affects the bikes gearing, try my little utility here.

 

[Top_Speed1]

So how about the term "Fatsider" eh eh??? When my car tire is due to be changed I think I'll look into this.

Rob

I LIKE THIS!

I'm certainly not the 1st but I do wanna be "Fatsider #1" lol

Any Fatsiders want in?? :yahoo:

 

[Top_Speed1]

As the old saying goes, if it works better for you and makes you happy then by all means. Other than a change in RPM going down the road, what's the actual footprint difference? I would tend to believe the stock size tire might turn alittle quicker. Cost vs benefits? Look forward to the feedback.

It has to have a bigger footprint with maybe just a tad more rubber on the ground. But as said, the (at least with my PR2 version) it is quite rounded and I'm thinking they (Michelin) wanted this pretty much all for the offset of the "additional" turning?. Like said I haven't felt this yet and as Ienwlf said, you can run a bit more air to offset? ...I haven't heard back what he runs yet and what brand tire he has...

 

[lnewlf]

Ho hum...benn running 190/55 ever since I got the FJR. Been flamed about the slower turn in [not noticeable,run a couple pounds more pressure]..As mentioned-rpm's are lower, mileage higher, looks better....All manufacturers list a 5.5 inch rim as acceptable fitment for a 190. A 200 is interesting but the tire is designed for a 6 inch rim and may be pinched so much that there would be no width gain. Hope someone tries it and posts up. Could always send the wheel out to Kosman and have it widened-we could maybe run a 240 [and it wouldn't be square..] Fat bottomed girls make the world go 'round..

Nice to know I'm not the only idiot out there :yahoo: ...maybe b/c were both from NY?

What lbs do you run the 190 at? Dealer pushed me out at 41

You guys can keep the fat bottom girls however! (and I believe it's "they make the rock'n world go round")

Yep- it is rock'n...and I guess most get fatter as time goes on..

I use PR2 at 44 psi-get about 9K on them and [hate to admit] about 1/4 inch chicken strips. 180 wears right out to the edge..

 

[carlson_mn]

190/55 is becoming the new standard on many models, from the k1600 to the ss1000rr bmw uses it on both, along with most new sport bikes. The increased ride height on the rear as well as more aggressive profile of the 55 vs. 50 series should make up for any "slowness" because of the 190 width. (lol).

With the added weight of the tire and the additional cost of the tire over the 180/55, I doubt you'll get any savings back at the pump with the couple less revolutions per mile the rear tire is saving you... plus the Gen2 FJR doesn't need its overall gearing any taller than it is already IMHO, although I understand most everyone enjoying less rpms on the highway.

A plus side is you will gain a smidgen more ground clearance. If prices come in line with the 180 I may try this size tire next.

 

[Top_Speed1]

A plus side is you will gain a smidgen more ground clearance. If prices come in line with the 180 I may try this size tire next.

Never thought of the (ground/obstacle) clearance side of things, but as said it sure does go up on center stand easier!

My buddy who owns the Goodyear shop in town says the overall tire industry is having a big jump in rubber/tire prices this fall. I don't think the 190 would ever drop to the 180 being there is more material involved but it sure sounds good