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

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so we should stock up on tires now?? :unsure:
Get me some low level behind the bench seats for the upcoming Vikes/49ers game and I will front your "Fatsider" set for you!!
I needed an excuse to pick up another tire so thanks to topspeed I grabbed the last Shinko 10 190/55-17 off the rack at Chaparral Moto, $132.88 plus the govs taxation. Looks to be a really boss tire, and even the kid at the desk nodded knowingly and liked it.....won't need it til next Summer but hey.....I'm ready.

 
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YER GUNNA DIE!!!!!!!!!!!
+1

A flaming death.
The World is Coming to an End as we Know it: SkooterG and RadioHowie agree on something!

What possibly can be next? 'Zilla is going to learn how to spell?
NOT gonna happen....EVAH!

Bust's going to give up sheep?
He's already transitioning to these:

m-tapir_img01-l.jpg


 
We went riding with Fencer at EOM last weekend. He was running a 190 rear (his PR3 was done and just happened to have this tire in his garage for his track bike).

He liked it - he's tall so the additional seat height was no big deal for him, and he mentioned something about better turn-in, but I don't understand shit like that.

 
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.
Jason,

Where does the "X2" come from? Looks to me like the total height increase is 5.5mm which I calculate to be .2165 inch or ~ 7/32 inch increase in rear tire height.

Slardy

 
Timely thread for me. Just received the PR3's I ordered from Sportbike Track Gear. $294 for 120/55-17 and 180/55-17 shipped. When I opened the box, oops, there was a 190/55-17 in there. Been pondering whether or not to give it a try. I've only ridden the bike with the squared rear and cupped front PR2's that came on it when I purchased it last month so I'm sure turn in will be fine compared to those. Think I'll give it a try.

 
Slardy, overall height (diameter) of the tire increases 5.5mm X 2, sidewall at top and bottom of tire. Will increase ride height 5.5mm, only one side of the tire in contact with the road (radius). I can adjust out the increased ride height if need be with my spankin' new Penske shock. :yahoo:

 
So I put on a 190/55 [have been using a 190/50] and rpm's dropped noticeably, speedo now reads 61 at an actual 60 [was reading 64] and mileage readout says 45+ instead of 47+. I'll have to check mileage myself to see if it dropped. Just did a 700 mile trip and the tire feels great-no turn in slowness with 44 lbs pressure.

 
...He was running a 190 rear...

He liked it - he's tall so the additional seat height was no big deal for him, and he mentioned something about better turn-in, but I don't understand shit like that.
I still really like my "FatSider" 190/55 and they do turn-in quite well. Coming from old rubber is a huge difference (of course!) so you have to recall that memory of when you had the 180/55 as still virgin-ess. I know in theory a wider tire is more "lazy" entering turns but I am running 42-44lbs (as another 190/55 user suggested) and it wants to dive into the turns quite nicely.

FatSider #1 :lol:

 
180/55: 99+432(rim dia.)+99=630*3.14=1978mm circ.

190/55: 104.5+432+104.5=641*3.14=2012mm circ.

This is less than a 2% increase in circumference. Should really be barely noticeable on the speedo at 60MPH.

 
Well, can't speak to the circumference of a 180/55 as I haven't used one in a while...However I used a tape to measure the worn 190/50 that I took off at just over 76 inches. The new 190/55 measured at 80 inches. That works out to @ 5% difference. At 64mph indicated, times 5% it would drop about 3 mph off the optimistic speedo. The sidewall height is considerably smaller that the total height of the tire-the profile is round [unless you are a darksider].

 
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 :eek: .
I just had a PR2 190/50 put on mine this morning (they didn't have the 55 sidewall in stock and the 190/50 was on sale cheaper than I could find off the internet). But I was looking at the swing arm clearance and I think a 200 tire would fit as well. There is about a 1/4" clearance on both sides of the 190 tire. I'm tempted to try that next time.

My last bike was a M109R and I had a 250 on that bike and I got used to it and rode the twisties just fine. It didn't slow me down any at all. The 190 width looks real nice on the FJR and I think a 200 might be about it for max size.

 
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Since when is a spin balance on a motorcycle tire more accurate than the static method?

Go to an AMA, World Superbike, or MotoGP race, and see how they balance their tires. They all use the static method. Wheel hung until the heavy spot is at the bottom and add weights until there is no clear heavy spot.

Don't waste extra money on a spin balance, it is not worth it.

 
I have checked the balance on 2 spin balance jobs with static. Found the weight in the right quadrant but the amount off by 25%. If you are going to spin balance you had best read up on how to use the machine. Most shop mechanics could give a shit. Good friend of mine just sold a BMW Honda Yamaha dealership. He had a spin but uses static at his house. Static is moooore better.

 
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