Aspect Ratio

[Shordy]

Was out for a good ride with another forum member yesterday when he so kindly made me aware that my rear tyre on my Gen 2 was not the original size, it's a 190/55-17 as opposed to a 50 series.
What's peoples thoughts on the subject as in any real benefit or negatives by changing to this size?

[Tony Nitrous]

I have a 190/55 on both my Busa and B-King,
(King is a 200/50 as stock)
Would have one on my GSX1400 too except
I'm really happy with the 50 profile tyre and 30mm jack up kit
and really don't want to be changing anything at the moment.
All 3 use the same 6" wheel.

Some folk will write a thread full of why its right or wrong
but I personal don't give a flying f@ck.

Its just a case of what the rider wants and what suits him.

Personally I find the different "shape" or profile can have almost
as much effect even when tyres are branded as being the same size.

I've seen several tyres lined up and there was a noticeable difference
even between those that were sold as being the same size.

5% may or may not be noticed but I don't see it as a drama.

Most folk think 5% is a big step as they normally go up or down
from a bald tyre to a brand new one.

Tony.J.

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.... on 2nd thoughts....

Its not standard / complianced / legal and your insurance won't cover you.

Take it off immediately!!!

I'll give you my address to post it to ;-) LOL

[Shordy]

Makes sense Tony. Since I've had the bike, I've been constantly surprised about how well it handles contrary to popular opinion, (insert the fridge analogy here), so maybe the tyre has a bit to do with it. It could also be because I'm generally used to riding heaps of shit and riding around their deficiencies.
Anyway I have no complaints...

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One thing you didn't mention though Tony is why you run that profile in the first place?

[mozzie26]

I have 190/55 Pilot Super Sport on my Gen 1 which is set up more for fun/track days. My Gen 2 has 190/50 Pilot Road 4's and is set up more for long distance touring. The Gen 1 feels so much lighter into corners I would have thought the whole bike was 10-20kg lighter. I weighed both bikes the other week, the Gen 2 was 254kg and Gen 1 was 255kg, my GSXR750 K5 was 192kg. My opinion is the 190/55 profile is better for the twisties and the 190/50 profile is better for straight line stability.

Glen

[Shordy]

Cheers Mozzie, I couldn't ask for a more unbiased opinion.....

[Tony Nitrous]

Just got back home from a few hours on mine.

Got a 55 profile S20 on the rear,
No steering damper for the last 7 or 8 years,
Feels a bit twitchy but very nimble for a big old Bus and controllable with wide bars.



photo uploading

[cyndemgum]

Always learning. Seems to me that the main reason for fitting a 55 percent aspect ratio is when you reach the stage where you are running off the edge of a 50 profile. If you are not using the full 50 series you will be nowhere near the edge of a 55. Have a blast, Paul.

[Shordy]

Always learning. Seems to me that the main reason for fitting a 55 percent aspect ratio is when you reach the stage where you are running off the edge of a 50 profile. If you are not using the full 50 series you will be nowhere near the edge of a 55. Have a blast, Paul.

It's a coincidence that you should state the above Cyn as it was only a week ago I was bragging to a long time riding partner that I have finally managed to get rid of my chicken strips, and that's with the 55...
I wouldn't say they were pilled up like a race tyre, but gone all the same, and it's all down to being comfortable with the bike, happy with the tyres and a piece of road I love being from Kersbrook to Williamstown...
Just some of the best 120-140 kph corners around me thinks....gets the adrenaline running....

[RaZ]

[shorty]

Aspect ratio? What does that mean? I always thought that it was the depth of your side wall in millimetres? Anyone own a tape measure?

[Batfink]

On a 190/50 that would make the side walls 95mm plus arc of tyre and that's where the contention is.... Some manufacturers use a higher walled tyre giving a greater radius arc and a different profile even though the tyre numbers are the same.

[Shordy]

Aspect ratio? What does that mean? I always thought that it was the depth of your side wall in millimetres? Anyone own a tape measure?

Just to answer your question, the aspect ratio refers to the way they measure tyres, example:
190/55-17 means 190mm wide, the height would be 55% of the width, and the rim diameter is 17", so the aspect ratio is 55% of 190mm.
Why they use a mixture of metric width and imperial wheel size has always intrigued me though.

[Batfink]

the tyre number would be funny if it was all metric

190/55-4318

I guess the easiest way to think about it is that the imperial numeral is more a size rather than measurement.. like saying L, XL, XXL