[eidian]

Okay, one thing that I've noticed on the Z1000 is that feels "weird" when I start to lean into a turn. I'm not saying that it feels "heavy" or that it feels unstable--it just feels weird. I read a review of the bike on the internet and the columnist said (direct quote from the article), "Initially, you notice a peculiar transitional sensation as the bike rolls over to the lean angle you’re demanding—perhaps because of an interaction between the very big (190-section) rear tire and the relatively small cross-section (120mm) front tire.". What exactly is he referring to? I totally agree with what he is saying, I just don't know how this is explained in terms of geometry/physics. From the first lean I ever made on the 500R I felt the bike and it seem to lean so easily--the Z1000, it's different. So what gives?

This ends word question 1 from Geometry 101.

A back story for my second question:

I was able to take a freeway off-ramp that I use every day to get to work on the Z1000 yesterday as fast as I wanted to because it was empty. It's a nice cambered, "gentle", 270 degree, uphill, right turn off ramp. When I could, I used to love taking the 500R on it going like 45 when it was empty (it was challenging)--just a little harmless fun before I step into the office. Well yesterday on the Z I took it easy and I was disappointed in myself because I got that "weird" feeling from question 1 and as a result I took the turn slow. The bike handled like it was rails but I just couldn't get myself to go faster and lean harder because I just don't know the bike yet. I estimated that I took the turn at about 25mph...when I was about to straighten out and take off, the speedometer read 45mph. "Huh!?" I thought..., "I must've twisted the throttle a little before I looked down". Well, I showed the bike to my co-worker/friend who rides also and he looked at the rear tire and asked, "What the hell are you doing!? Are you nuts!? You picked up the bike last night and you're already leaning it close to the edge!? Dude, you don't even have 80 miles on the bike--between not knowing the bike and the silicone that's still on the new tires, you're gonna low-side!". I said, "What are you talking about!?...Are you f-ing whacko!? The closest thing that even resembled anything that could be called 'leaning' was the dumb freeway off-ramp that I took earlier...but that was nothing special...". Then I looked at the tire, he was right...I wore off most of the nubs on the right side of the tire and the silicone was rubbed off to almost a consistent 3/8's to 1/2" from the edge. I didn't know what to say; I knew how far I was leaning on the 500R and the tire showed it. I worked that tire to the edge and I knew it because I've rubbed my boot on the ground accidentally because of it--not so with the Z, I can't tell crap. My conclusion is that I guess I did take the off-ramp going 45 mph and I was leaning over a lot more than I thought I was--I just couldn't feel it.

So here's question 2: do wider fat tires make leaning feel different than narrower tires? If you can use the 500R vs Z1000 comparison, that would be awesome.

That concludes question two and my inquiry about tire geometry. Thanks for reading and answering.

 

[A2rider]

As I don't ride a sportbike, I'm very interested in seeing the answers. I would say it has to do with the width of your tire, plus the totally different geometry of the two bikes.

I'm sure Bennice, and Ervins, and hopefully Mayo will see this soon.

 

[RichLockyer]

A wider rear will take a little more "push" to get it to lean into the turn.
I hear similar comments from Victory owners who compare the Hammer to the Kingpin... their front end geometry is similar, but the Hammer sports a 250/40-18r, 130/70-18f, while the Kingpin runs a 180/55-18r 130/70-18f

 

[daemon]

true that rich.
a wider(190-50)lower profile tire will take extra effort to get to the lean angle.
there are many discussions on whether it is appropriate to change the size(dimensions) of the tires that the manufacturers has set aside for the bike.
point 1.
my zed came with the same sizes as yours. first tire got an invader and needed replaced.
only one availiable was a 200. what a pain in the arse to tip it over and very squirrely when tipped hard.
wore that tire out and went back to my 190.still not pleased with the feel of it,i did some research and made a decision.
i went with a 180-55. less width,higher profile tire.
the bike just slams over now,i basically have to fight the bars to keep it from falling clear over.
this feeling takes a bit of getting used to.

now back to the manufacturers suggestion part.
in the "total control" seminar i attended it is said that you should stick to the manufacturers suggested tire. the rims are of the size that should be appropriate for the style of riding that the bike was intended for.

EX: Z1000- 190-50-17,120-70-17
by putting a 180-55 on the rear of the zed it is making no difference at all(that's what they say) because in essence you are stretching the tire out of proportion depending on the size of tire and rim.

i tell you i will never go back to the 190-50 profile tire.
you just bought the bike and i'm certain you are in no hurry to buy new tread for now. just remember what the bike feels like now and when you are ready for the next set(continental road attacks)(shameless plug) get the sizes that i suggest.
then tell me what you think.

really eidian,go to RiderForums.com Community - Powered by vBulletin most of the peeps there are helpful in regard to the zed. there is a Z1000 specific area there.
if anything peruse around a bit and see what the buzz is about.

 

[Charlie Gary]

There's quite a few pages explaining this in the book "How And Why - Motorcycle Design And Technology" by Gaetano Cocco, but the basic answer is a larger tire requires more lean to achieve the same turning radius at the same speed than a tire of narrower width.

 

[JimmyD]

Which is why the "fat tire" phenom on cruisers is so funny. My vulcan cornered pretty well with a 110/150 setup. The geometry of any cruiser will allow it to corner relatively well actually. But a lot of guys think they're riding a raked out custom and set a 210 on the back on a 900 with too small a rim, so they're effectively now riding on a contact patch the size of a pencil eraser.

It's just a handling killer and I don't get it. Looks nice on customs though which aren't exactly designed to cut a corner anyway.

 

[eidian]

Okay, so I guess I should attribute that "weird" feeling when I start to lean as just the way the handles?

And since I have wider tires now, I guess I'll just have to adjust my turning technique? Learn to lean even more to get the bike to turn? I'm just a little concerned because I did get so close to the edge of the tire when I didn't really try.

 

[honestlyinsane]

I bet all you have to do is get some ride time.
I have had 3 different sportbikes a zx6e 97 zx9r and my 02 zx12r and I occassionally ride the wifes zx6r I have ridden a 97yzf 1000 and every bike made me uncomfortable when I first rode it When I bought my meanie I couldn't believe how weird it felt now I can go back and forth between bikes like its nothing. Once you adjust to the feel of the bike you will be set.

 

[stefano]

That's weird Ed.

Well if you are getting this "weird" feeling turning in both directions, then it definitely has to do with the different set-up of the Z compared to your EX. On the other hand if you were only getting the weird feeling turning one way as opposed to the other you could have said one of the wheels wasn't aligned properly - but that's a different story altogether.

Unfortunately I only have experience on my 636 and somehow on that bike, everything just came naturally, nothing felt or feels weird. Only question mark I have is at high lean angles, I get the impression that the front end wants to get away from me. I don't know if it's just my impression and I have to get over it or if I'm doing something wrong and need to adjust my body position or something... but this is the only time I feel uncomfortable on the bike.

Also, on the 636 you REALLY have to work hard to wear the chicken-strips out at the back :biggrin:

 

[bross]

Okay, so I guess I should attribute that "weird" feeling when I start to lean as just the way the handles?

And since I have wider tires now, I guess I'll just have to adjust my turning technique? Learn to lean even more to get the bike to turn? I'm just a little concerned because I did get so close to the edge of the tire when I didn't really try.

Don't worry, 1/2" isn't that close to the edge on your rear tire, you still have a lonnnng way to go, lean wise. Once you get comfortable and start really leaning, you'll probably notice you don't have any chicken strips on your back tire, while you still have a bit of chicken strip on your front. The 190 is fairly wide, I would think what you're feeling is just the wider rear being more difficult to tip in, as suggested.

I second mayo's suggestion about trying Conti Road Attacks. I replaced the Metz Z6's on the RT with Road Attacks and noticed an immediate boost in cornering confidence. Not exactly sure what it is, there was nothing wrong with the Z6's, but the Conti's just seem more fluid, and I am cornering more confidently and quicker than I ever did on the Z6s.

 

[ervins]

You want weird? Try a 190/55 tire in the rear...When I first got on the 10R...I knew the turning was not as precise...However, when I first leaned, I thought I was going to fall over...I am not really keen on that feel...Then again I am not really keen on the Qualies that came with the tire. But yes, that is the general nature of a wider tire...The 190/50 should feel a little sluggish but not that much...A 190/55 turns quick. The Pirellies I have waitng to be mounted when I get time are 190/50...So yes, I am actually swithcing to a none OEM size. I do not need quick response from the rear, since I do not have the issue of leaning my body over...So in answer to you question. The rear profile is what makes it feel weird but also, the bike as well. You will get used to it. As far as how much you have leaned, relative to your old 500 and Z1000, you are probably at the max of your 500 but still have some to go on the Zed. But yeah it is thrilling bro. It is a different feel...I feel the profile on my tires are just to aggressive that I lose "feel" when turning. I will let everyone know how my 190/50 experience goes with the Corsa IIIs go compared to the 190/55 of the Qualies. I was speaking to an AMA rider who has a shop in my area (not my regular shop) and he said he prefers the 190/50 over the 190/55...He did not like the quick "turn in". Like I said I will let you know. You're all good...After a while you won't even feel it.

 

[zedx11]

even in the same tire dimensions you will have a different curve profile on the tire. you can see the differences in the pictures on the tire sites. I have also read different reviews of tires that brought up the fact that the different shapes of the tires made them easier/harder to turn.

 

[ervins]

even in the same tire dimensions you will have a different curve profile on the tire. you can see the differences in the pictures on the tire sites. I have also read different reviews of tires that brought up the fact that the different shapes of the tires made them easier/harder to turn.

Ver true! Some tires are shaped differently. I would like a more neutral tire.

 

[stefano]

even in the same tire dimensions you will have a different curve profile on the tire. you can see the differences in the pictures on the tire sites. I have also read different reviews of tires that brought up the fact that the different shapes of the tires made them easier/harder to turn.

Absolutely.

The "flatter" a tyre is (in terms of cross-section profile), the harder it is to lean over but at the same time it is more "predictable", so theoretically it should give better feel in the intermediate lean angles.

Conversely, the more "peaked" the tyre is, the quicker it turns in, but at the same time there is a "range" of intermediate lean angles where the bike feels a little wobbly and it is hard to predict the level of grip. However these kinds of tyres should also provide more grip at high-lean angles as the shape of the tyre maximizes the contact patch at these lean angles.

Or so the bike magazine tyre testers say :biggrin:

 

[bross]

Absolutely.

The "flatter" a tyre is (in terms of cross-section profile), the harder it is to lean over but at the same time it is more "predictable", so theoretically it should give better feel in the intermediate lean angles.

Conversely, the more "peaked" the tyre is, the quicker it turns in, but at the same time there is a "range" of intermediate lean angles where the bike feels a little wobbly and it is hard to predict the level of grip. However these kinds of tyres should also provide more grip at high-lean angles as the shape of the tyre maximizes the contact patch at these lean angles.

Or so the bike magazine tyre testers say :biggrin:

You mean like this...:biggrin:

 

[A2rider]

^^^^ No chicken strips on the left one. Not now, not ever! LOL

 

[bross]

^^^^ No chicken strips on the left one. Not now, not ever! LOL

Sure there is, it's got a'bout a 3" chicken strip! ;-)

 

[bross]

OK even sillier than on a chopper...

and I think fat tires are silly on anything except a monster truck.

 

[A2rider]

OK even sillier than on a chopper...

and I think fat tires are silly on anything except a monster truck.

Kind of defeats the whole point of a sportbike, dontcha think? :biggrin:

 

[bross]

Kind of defeats the whole point of a sportbike, dontcha think? :biggrin:

Uh Huh.