Tire Question: Fatter tire = less performance while leaning?

ghost_a* · 09-21-2006, 06:47 PM

as you can see, i own an '04 Gixxer 6.
the stock specs on the rear tire is a 180.
i'm the 2nd owner of this bike, this is my first bike.
i have around 8,000 miles of seat time on this bike alone since last november.

my question is this, after buying this bike and riding for a month or so a friend of mine realized that the rear tire on my 600 is a 190. not a 180. obviously meaning that my rear tire is a fatter tire, actually meant for a gixxer 1000, not a 750, let alone a 600.
i've never noticed a problem. i've ridden farely hard, not scraping knee or anything, but to the point where my chicken strips are about half an inch on either side.

my friend has been telling me that the fatter tire inhibits the leaning. meaning that with a 180, it's not only safer, but it's better for performance when taking a curve at a really aggressive lean.

is there any truth to this?
i'm taking a ride up to sedona, az from phoenix, az next month and there are some pretty nice twisties. i'm second guessing my tire now and thinking i should swap it out for a 180...

when i bought the bike the previous owner had just put a brand new pilot on the rear. i've since replaced the front with a brand new pilot, but the rear looks to have at least 40% tread left on it.

kevinwilly · 09-21-2006, 07:10 PM

Well, it depends.

It's really a matter of profile more than just size alone.

My bike has a 6 inch rim. It normally calls for a 190/50. I have a 180/55 on it right now, which is actually *slightly* taller and narrower than the 190/50.

This helps it turn into corners better.

You probably have a 5.5 inch rim. (or so i'd imagine). So squeezing the 190/50 tire into that harrow a space *may* make it steeper.

Or it could be a 190/55, which is an even TALLER profile than the 180/55.

I would think that the 180/55 would be the best option for a rim your size, though.

I haven't compared the two, but everyone i talk to that's in the know says that the 180 is better for performance.

So there you go... i guess...

firefighter81 · 09-21-2006, 07:29 PM

Unless you've done some serious track riding before and you feel that you can outride the tire you have on it now, don't worry about it.

A 180 will give you quicker turn-in and the bike will "feel" lighter, the 190 will give you better stability at maximum lean. This is a generalization, there are exceptions to the rule, but for the most part this is how it works.

02gixxer600 · 09-25-2006, 10:39 AM

I have a 180/55 on my gsxr street bike and a 190/60! on my gsxr track bike.. track bike is stable and street bike turns in quick. just like said before.
shouldn't be too big of a deal on street riding. have fun in the twisties

i also had a 190 on my first street bike from a previous owner and i switched to my first 180 and damn was it a huge difference.. I had only been riding about 6 months but the difference was actually unnerving and if you havent riden on a 180 in the twisties before no need to change until after (assuming you have enough tread on your 190)

ghost_a* · 09-25-2006, 10:55 AM

Quote:

Originally Posted by 02gixxer600

I have a 180/55 on my gsxr street bike and a 190/60! on my gsxr track bike.. track bike is stable and street bike turns in quick. just like said before.
shouldn't be too big of a deal on street riding. have fun in the twisties

i also had a 190 on my first street bike from a previous owner and i switched to my first 180 and damn was it a huge difference.. I had only been riding about 6 months but the difference was actually unnerving and if you havent riden on a 180 in the twisties before no need to change until after (assuming you have enough tread on your 190)

yeah, i've never ridden on anything but my 190 on this bike.
i'll just ride it out 'til the need is there for a new one then switch to 180.

so the 190 being more "stable" meaning that there's less shutter in a lean? or meaning....what exactly?
can you go into a bit more detail there?
thanks again for your comments guys

02gixxer600 · 09-25-2006, 11:24 AM

Quote:

Originally Posted by ghost_a*

yeah, i've never ridden on anything but my 190 on this bike.
i'll just ride it out 'til the need is there for a new one then switch to 180.

so the 190 being more "stable" meaning that there's less shutter in a lean? or meaning....what exactly?
can you go into a bit more detail there?
thanks again for your comments guys

too me it just feels smoother.. more like a caddy versus a corvette. when i get the street bike it doesn't really feel unstable i guess but rather a little bit looser. It drops into the turn a lot easier but at full lean doesn't hold its line as well as the track bike. its just because it takes so much more input on my track bike to do something ( I call it a stubborn mule actually) so any slight movement on the street bike causes it to move and on the track bike its not the case. (modifications has something to do with this but a lot is the tire)

Its kinda hard to explain because the biggest difference is turn in to me.

hopefully this isn't just rambling and answered your question kinda.

ghost_a* · 09-25-2006, 11:45 AM

i guess i see what you mean.
you can hold a more consistant line with a fatter tire. the bike strays from that line less, i guess is what you're getting at?

either way i think i know what you're saying.
it seems that in the actual line, there's more control in the rider's hands with a thinner tire, being that they have to hold the line harder.

we'll see how it feels when i get a new tire sometime in the coming months. i'll switch to a 180.

thanks again guys

02gixxer600 · 09-25-2006, 02:54 PM

thats the best thing... youll see what im saying when you get it on

ghost_a* · 09-25-2006, 03:01 PM

Quote:

Originally Posted by 02gixxer600

thats the best thing... youll see what im saying when you get it on

yeah i'll take it out and ride pretty hard on like a friday night (well as hard as i can on a tire that needs changing, haha), then saturday morning i'll get 'em swapped and i'll take it out again to feel the difference.

thanks.

whitman · 09-25-2006, 04:41 PM

part of the reason for the wider tire on the bigger bikes is to handle the power upon acceleration out of corners especially. a 600 just does not make enough power to need it and the bike will feel better and easier to ride on the street with the smaller tire. Check with the tire mfg's to see what they recomend for the bike, not what they would sell you.
whit

Lewd Ferrigno · 09-25-2006, 09:25 PM

There is another thing you should consider. Most people that go to a bigger tire in the rear, or change from the stock tires for that matter, never compensate for the change in geometry.

For instance, if the height of the rear tire is 10mm shorter, then the rear ride height is reduced 10mm.

These measurements will have a far more profound effect on a bike's handling than a change of profile. If you make compensating adjustments when making a tire change to maintian the geometry of the bike, you will find that a profile change doesn't make that much of a feeling difference to a normal rider.

ghost_a* · 09-28-2006, 09:28 AM

i also had another question regarding "chicken strips".

i took a run saturday morning and was leanin' pretty aggressively yet i looked at my tire and i still have a little under half an inch of strip left.
i commute often and ride a lot on the freeways so i'm sure that has something to do with it, but does the fatter tire also make it harder to get rid fo the strips?
i would assume so being that there's more surface area on the contact patch of the tire.

Lewd Ferrigno · 09-28-2006, 10:25 AM

Racers who run in the top 5 of AMA nationals have a half inch of unused tire. Don't place stock in chicken strips, especially on the street. You'll never need to lean that far on the street.

Plus, you really should be doing that kind of stuff on track.

ghost_a* · 09-28-2006, 10:33 AM

Quote:

Originally Posted by Fargin_Bastige

Racers who run in the top 5 of AMA nationals have a half inch of unused tire. Don't place stock in chicken strips, especially on the street. You'll never need to lean that far on the street.

Plus, you really should be doing that kind of stuff on track.

this was my way of thinking also, where "street riding" is concerned. but as far as canyon riding?
either way i was just curious. thanks for clarifying.

Lewd Ferrigno · 09-28-2006, 10:48 AM

Quote:

Originally Posted by ghost_a*

this was my way of thinking also, where "street riding" is concerned. but as far as canyon riding?
either way i was just curious. thanks for clarifying.

Canyon riding claims a lot of single bike accident victims. Canyons are still street s and covered in oil, antifreeze, diesel and other crap.

Take it to the track. Street riding is a pale comparison. It's honestly boring and more dangerous.