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

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Hi Auron,

I couldn't agree with you less. Rarely is there a free lunch, but that's what you get by upsizing. There's no downside--I'm changing tires anyway--and just having an accurate speedo makes the switch worth it to me. Better handling without having to mess with the suspension is a bonus. To paraphrase JFK, you ask, "Why would you switch?" I ask, "Why would you not?"

 
lotta bikes [ie duck] come thru with a 190 0n a 5,5 rim...check the manufacturer's acceptable rim fitments and you will see that 5.5 is OK for a 190....actually a good idea in some cases...

 
I can't believe this thread hasn't been nerp'ed.
190/55 is a terrible idea on a 5.5.

The only thing you guys are noticing is the benefit to raising the rear end up. Get a proper spring on the back and use the damn 180. The 5.5 is a perfect match for a 180/55. Amazing you would mess with that.
.Other than your opinion, what scientific data do you have to back up the claim? Kinda sounds like SWAG. In my opinion, using a 190/55 on FJR's is a concept that may become an idea!!

A. Einstein

 
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All you need to do is look at the amount of un-used rubber,

Good luck finding one OEM bike with a 5.5 190/55 combo. You can't and that should tell you right there it's a bad idea.

Sure when you throw it on there and "WOW this thing feels so much lighter I'm so glad I did this" and that's great but if you plan on cornering very hard so are going to have amuch smaller contact patch plainly visible by your 3/4" or more chicken strips.

Simple steering geometry is all the scientific data I need.

Use and 180/55 WITH a proper spring on the back and tell me it's better than stock with a 190. To each his own and even if a car tire floats your boat that's great. If optimal cornering performace is your goal, a 180 with a new rear shock is your best best.

 
HRZ said:

Nevermind...Dumb irritates me and makes me say mean things

Palerider said:

Life is like a box of chocolates....

Actually I think he's trolling.

 
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Nothing dumb in post 323. Go ahead, find me a stock bike with a 5.5 190/55. Good luck.

 
Nothing dumb in post 323. Go ahead, find me a stock bike with a 5.5 190/55. Good luck.
Auron,

You may have a valid position, but you're not supporting it well, which is why Art Miller asked you to provide more than just your opinion. The argument you have provided is, at best, specious because, with the exception of a few luxury brands, manufacturers don't use the best tires on new bikes; they use the cheapest tires that will provide minimally adequate performance. Thus your argument that there's somehow something wrong with using 190s because the stock bike comes with 180s is, I think, what HotRodZilla, in his own gentle way, refers to as dumb. Now nobody here knows everything (well, except maybe Howie), and we all want to learn from intelligent observers, so we'd just like you to better support your position, which to judge from your tone, exhibits cranial rectitis.

 
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If unused rubber were the overriding issue, I would have to be a darksider.

I don't care what anyone says. I have used them for the last 42,000 miles. I found the FJR's peg/ground clearance to be substantially less than on my under powered, vibrating, rough 1993 K100RS. In fact, I found the ease with which I could scrape pegs to be quite disconcerting then annoying. The added width has reduced peg scraping by 95 percent. I see tires that I will need anyways to be much more preferred to spending money on a new aftermarket rear shock to raise the bike and make it ride stiffer, such logic is SILLY not SCIENTIFIC.

 
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There is only one significant down-side to the Upsize: Cost of the skins.

For those that have super-sized their tire on a 3rd Gen with the improved center stand, the bike must virtually lift itself...

 
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'Zilla not stirring the pot just gives me goosebumps. This place is getting NICE-errr!
smile.png


 
Oh yeah, the age-old "design engineers know what's best" argument. To each his own but riddle me this Batman: how is it that tire and wheel engineers know what's best for the bike but it's ok to change what the rear shock engineer used? How come as a gawd-almighty engineer he didn't know what the best is?

Gimme a break. If you try it and you like it then go with it. If you try it and you don't then don't. That reasoning I'd listen to. But please don't think the rest of us are so stoopit or gullible as to buy into your trolling bullshit simply b/c you say so.

 
I was going to "like" rbentnail's post but I don't necessarily want to echo the "trolling bullshit" stuff. Nevertheless, he makes a good point about picking and choosing why some OEM specs would be okay to mess with and others aren't. All I can say is that the cornering performance/ride/feel on the 190/55 feels so much better to me that I won't go back to a 180/55. Oh yeah, and even if an after-market suspension would have achieved the same result (and I'm not necessarily convinced that it would), at least I didn't have to pay big $$$ to get that result.

*Edit* - "...picking and choosing..."

 
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I was going to "like" rbentnail's post but I don't necessarily want to echo the "trolling bullshit" stuff. Nevertheless, he makes a good point about picking and why some OEM specs would be okay to mess with and others aren't. All I can say is that the cornering performance/ride/feel on the 190/55 feels so much better to me that I won't go back to a 180/55. Oh yeah, and even if an after-market suspension would have achieved the same result (and I'm not necessarily convinced that it would), at least I didn't have to pay big $$$ to get that result.
Yes, I'm still scratching my head over this one. I can get the same result by spending $12 (the difference in cost between a PR4 180/55 and 190/55) or spending who knows how many hundred dollars and who knows how much time tweaking my rear suspension. Hmmm. Cake or death?

The more I think about the argument that you shouldn't change to a different-sized tire because that's not what came stock, the sillier it seems. If I'm taking a BMW 1000 RR for a track day, should I not put a slick on it because that's not what came stock? If I'm taking a dual-sport out for a day in the dirt, should I not put different rubber on it than the one that came stock for combined street/dirt riding?

 
I'm surprised that nobody has mentioned that when you change the rim size for any given tire, you also change the shape of the tire and how much pavement contact the tire is going to have at any given lean angle. The tire manufacturers all seem to think that a 5.5 inch rim is the best rim size for a 180/55 tire, just because a 190/55 will fit on 5.5 rim doesn't mean that it is going to work as well as the 180/55.....although the difference in performance may be negligible.

 
Nothing dumb in post 323. Go ahead, find me a stock bike with a 5.5 190/55. Good luck.
My K16! ....well, I didn't have to look very far for that! :)

pu_day_03-01-14_a_zps4836733e.jpg


Not stirring btw, but as the OP of this, I guess you know my stance. It's just a betta choice than the 180/55 (for most peeps, and just about everyone who has tried it has reported as such).

 
I was going to "like" rbentnail's post but I don't necessarily want to echo the "trolling bullshit" stuff. Nevertheless, he makes a good point about picking and why some OEM specs would be okay to mess with and others aren't. All I can say is that the cornering performance/ride/feel on the 190/55 feels so much better to me that I won't go back to a 180/55. Oh yeah, and even if an after-market suspension would have achieved the same result (and I'm not necessarily convinced that it would), at least I didn't have to pay big $$$ to get that result.
Yes, I'm still scratching my head over this one. I can get the same result by spending $12 (the difference in cost between a PR4 180/55 and 190/55) or spending who knows how many hundred dollars and who knows how much time tweaking my rear suspension. Hmmm. Cake or death?

The more I think about the argument that you shouldn't change to a different-sized tire because that's not what came stock, the sillier it seems. If I'm taking a BMW 1000 RR for a track day, should I not put a slick on it because that's not what came stock? If I'm taking a dual-sport out for a day in the dirt, should I not put different rubber on it than the one that came stock for combined street/dirt riding?
Ok, fair enough about the trolling thing. It just gets my temper up when someone spouting "don't change it 'cause it's not what came on it", often speaking out of both sides 'cause it's ok to change other stuff. We change seats and handlebar heights and windshields and suspension and ... and ... and ... and... and all that's ok but we're not supposed to deviate at all on tires? Nearly every other design engineer is completely clueless but the tire guy- that Magical, Fearful Man Behind the Curtain, he knows his shit and is not to be questioned? I repeat- gimme a break.

To each his own. Give 'it' a shot. Hell if 'it' doesn't kill ya how bad can it be? You might even like it.

 
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