[Aufitt]

Before anyone makes an incorrect statement, the 4.5 inch rim will accept 150/60 properly.

Why would you put a 4.5" wheel on an R3?

 

[Maven]

Agreed.. 7mm is huge... Good thing I took a few inches out of my ride height to start with. No more dirt bike.

I guess the difference between you and I, comes down to: I buy a small engine street bike to drive to work. Comfort and looks are paramount. The change in geometry to any bike is not rocketry, and I'm baffled as to how everyone is treating it as such. You can check ride height front vs rear, you can throw a digital protractor on the triples and forks .. drop a plumb bob and check your rake/trail... the multitude of online calculators lets you dive even deeper with relative ease...
My bike is not a race bike. ... maybe yours is some sort of race machine.. but it is silly to treat everyone as if they're going to race their bike...I would wager most of the R3s sold will never see a "track". Mine has well over 3k on the tires and the rear still has the knubbies on both sides.... so... yeah...

140/70 is taller than the incorrect 150/60.
7mm ride height is huge, so is 200 grams unsprung spinning weith.


Ask any track rider or racer what size gives best performance.
We don't buy tyres to look.

 

[Capitalview]

Agreed.. 7mm is huge... Good thing I took a few inches out of my ride height to start with. No more dirt bike.

I guess the difference between you and I, comes down to: I buy a small engine street bike to drive to work. Comfort and looks are paramount. The change in geometry to any bike is not rocketry, and I'm baffled as to how everyone is treating it as such. You can check ride height front vs rear, you can throw a digital protractor on the triples and forks .. drop a plumb bob and check your rake/trail... the multitude of online calculators lets you dive even deeper with relative ease...
My bike is not a race bike. ... maybe yours is some sort of race machine.. but it is silly to treat everyone as if they're going to race their bike...I would wager most of the R3s sold will never see a "track". Mine has well over 3k on the tires and the rear still has the knubbies on both sides.... so... yeah...

By your statement then, safety doesn't even enter your equation for a street bike? While the change in geometry may have little or no difference at "normal" posted speed limits, what happens to the non track person who decides to take the R3 to it's upper speed potential who has made these changes? Have you ever heard of high speed instability? That is something you are not taking into account.

What about the change in the center of gravity from the ride height change?

How did you figure out the ride height change? Did you just take the specs for the manufacturers web site? Or did you actually put a tape measure around the tire to determine what the actual tire diameter is. You would also have to know what the original tire diameter had been, while the tire was mounted to the rim. That really is the only way to figure out the true ride height change.

While you have a lot of riding experience and may be able to ride out of any issues this change may entail, most, according to the experience poll, have less than 3 years. These new riders who are buying the R3 as a beginner bike will, most likely, push these bikes beyond the riders ability. Are they going to be able to compensate or deal with the risks associated with changing tire sizes, and there by, steering geometry? And yes, there are risks when you deviate from factory specs. Those of us with more experience should let the newer riders know about the risks of changing geometry and tire sizes.

Especially when you are testing this out on the street! At least if I try it out, I am on the track, in a controlled environment. I am in full leathers, helmet, gloves, armor, and a Leatt brace. I have paramedics standing by and runoff room with no obstacles.

 

[Maven]

Dude, If you think going from 140 to 150 is going to make that much of a difference, please provide ANY actual data to support that it is unsafe. It simply isn't enough to make a big difference in the handling of this bike. Take stock geometry.. modify tire size by even 20mm and report back which measurement you feel puts it in an unsafe category(other than perhaps being too large for the rim, but rims can be changed), and your method for determining risk(standard risk assessment). Heck.. even go 10 or 20mm in the opposite direction...

There is a time and place to be a debbie downer... 10mm on a tire size probably isn't it. Don't forget to tell everyone the risks of fender eliminators and aftermarket grips while you're at it! Then follow it up with a lecture on the dangers of lowering the bike... oh wait that one has already been proven to be no big deal...

 

[Capitalview]

Again, for you, go for it.

As for new riders with VERY limited experience they should be made aware that this will change how the bike rides. If being safe and letting new riders know not to rush into things without having all the facts is being a Debbie Downer, than that is me.

I never said it was unsafe. I said there are risks in changing the geometry from stock. It will change how the bike steers and rides. As for data, lowering the bike, WITHOUT lowering it in the front the same amount, will make the bike turn in slower. Period. Fact. That slow turn in may make the difference between a crash or staying upright for a new inexperienced rider who was used to how the bike reacted on the 140. You have also just lost ground clearance by lowering the bike and risk scraping parts when going through a corner fast. How does the inexperienced rider react to hard parts hitting the ground? Usually, that doesn't end to well.

You also seem to be looking at this from only your perspective as a commuter. I am looking at this as how I was when I was 19 on my first sport bike. Go out and push it as far as you can. Go as fast as I can and have fun. Max out the top speed on the highway. Try to mimic the racers I am watching and drag a knee through the corners. Only thing, when I started there was no internet to hear about the pros and cons about changing tire size or geometry. There were no experienced riders to go to in my area either.

My #1 goal in posting a response to you is keeping new riders safe. Letting them know what the risks are and then letting them make an INFORMED decision. I didn't say don't do it. I am just saying, think before you act and have as much information as possible. If you still want to do it, go for it.

I'm done. Won't beat this dead horse anymore.

 

[Maven]

'Fearmongering' is the term for it...

You're talking like people are adding anywhere near enough to actually make a very noticeable difference in the handling of the bike... which is simply not what was being discussed in this thread. Add to that.. this is such an incredibly docile bike to start with.

Excuse me while I head over to the stainless braided brake line thread and whip up some fear over how if they cause an accident and a Vehicular Accident Reconstruction Investigator finds out that they changed their own brake lines they're going to jail and losing their house...

 

[Aufitt]

10mm wider tyre wont 'look' any wider as its on the same 4.0" rim.


All you will end up with is doughy handling, less grip, more weight, less power, tearing, less life, lose heat quickly, and less contact patch on the very edge where is wraps around the skinny rim and falls away on the side, (not to mention the ass end of the bike is now lower again at this point)


If a rider cant tell the difference in feel, then why do they want a 150?
Don't give the old line about no sizes avail, there are heaps from Bias ply to great Radial offerings from Bridgestone and Pirelli that no rider on this forum could outride.


My mate races a KTM.... guess what, runs a 140, same 4.0 rim we have.
250 size bikes just cant keep the heat,
eg my tyres leave the pits @ 89 degrees, after a short 6 lap race they can be down to 48 degrees, but at least with the 140 the heat is more uniform.
On the road you wont ever get the same kind of heat needed to take advantage


If its looks that New road riders want?
well go ahead and run a 150 and more chicken strips than KFC.


What 'looks good is a tyre that has been working perfectly designed by engineers far smarter than the average muppet.


This looks good, my MC41 4.0 inch rim BT003 140 (same as R3 with 140)
Even wear, even heat, no tearing worked better as a tyre than I'll ever be as rider,
If anyone is getting better than this on their first Lams bike on the road better ask Yamaha Racing when that #46 bloke is retiring-

Now a prime example from my own experience,
cold tearing on my Ninja 250 one day old Supercorsa 150
(this is extreme but posted as a prime example of what the more experienced folk are saying.
Its the equivalent of going a 160 on a 4.0" R3/MC41/MC22/N300/VTR etc. for starters 15mm chicken strip on the side is a waste, this is why the heat goes, the tearing happens and a highside waiting to happen because If I lean one more degree that unused chicken strip which is parallel to the wheel is where the tyre is unworkable.-

Same bike but with 140 DR2 on 3.5" rim, (equivalent of 150 on R3), marginally better but still that mid corner tearing-

Does anyone notice the 150 'LOOKS narrower than the 140?
Does anyone see how the tyre is a nicer sharper shape, plenty of contact patch on the side, less in the niddle for better tip in, less rolling restance and higher performance.
The 150 looks worse the more you lean.


Why do I even respond to these sort of threads?
but if it keeps a new rider safer, smarter, and more money in their pocket to spend on better gear, a track day or rider training, then my work is done.

 

[t-rav_12]

If its looks that New road riders want?
well go ahead and run a 150 and more chicken strips than KFC.

What 'looks good is a tyre that has been working perfectly designed by engineers far smarter than the average muppet.

Why do I even respond to these sort of threads?

Uh..., I thought you did it for MY personal entertainment.
I approve of Aufitt's message.

 

[Stirz]

'Fearmongering' is the term for it...

Excuse me while I head over to the stainless braided brake line thread and whip up some fear over how if they cause an accident and a Vehicular Accident Reconstruction Investigator finds out that they changed their own brake lines they're going to jail and losing their house...

1. I suggest you not do that.
2. Upgrading brake lines (or brake pads or headlights or tires, ad nauseum) will not cause you to go to jail or lose your house.
3. Keep in mind over half the forum are first-time street bike owners. Promoting substantial changes in tire profiles to riders who may lack the experience to know what these changes will do is not exactly prudent. Not saying it should not ever be done, just that there are risks and consequences associated with those changes.

 

[sendler]

Even wear, even heat, no tearing

Excellent magazine article quality post and very informative photos.

 

[Maven]

It is called sarcasm, duder, I was openly mocking that other chap for fear mongering over a minor tire size change. And I stand by it...

1. I suggest you not do that.
2. Upgrading brake lines (or brake pads or headlights or tires, ad nauseum) will not cause you to go to jail or lose your house.
3. Keep in mind over half the forum are first-time street bike owners. Promoting substantial changes in tire profiles to riders who may lack the experience to know what these changes will do is not exactly prudent. Not saying it should not ever be done, just that there are risks and consequences associated with those changes.

 

[Maven]

You almost had credibility. Then you threw out the "more chickens strips than kfc" thing. And then you lost it all. The type of person that give a sh!t about chicken strips has zero business riding on the street. period.

Fiiinnee... in a couple weeks i'll order a 150 i guess.

10mm wider tyre wont 'look' any wider as its on the same 4.0" rim.


All you will end up with is doughy handling, less grip, more weight, less power, tearing, less life, lose heat quickly, and less contact patch on the very edge where is wraps around the skinny rim and falls away on the side, (not to mention the ass end of the bike is now lower again at this point)


If a rider cant tell the difference in feel, then why do they want a 150?
Don't give the old line about no sizes avail, there are heaps from Bias ply to great Radial offerings from Bridgestone and Pirelli that no rider on this forum could outride.


My mate races a KTM.... guess what, runs a 140, same 4.0 rim we have.
250 size bikes just cant keep the heat,
eg my tyres leave the pits @ 89 degrees, after a short 6 lap race they can be down to 48 degrees, but at least with the 140 the heat is more uniform.
On the road you wont ever get the same kind of heat needed to take advantage


If its looks that New road riders want?
well go ahead and run a 150 and more chicken strips than KFC.


What 'looks good is a tyre that has been working perfectly designed by engineers far smarter than the average muppet.


This looks good, my MC41 4.0 inch rim BT003 140 (same as R3 with 140)
Even wear, even heat, no tearing worked better as a tyre than I'll ever be as rider,
If anyone is getting better than this on their first Lams bike on the road better ask Yamaha Racing when that #46 bloke is retiring-

Now a prime example from my own experience,
cold tearing on my Ninja 250 one day old Supercorsa 150
(this is extreme but posted as a prime example of what the more experienced folk are saying.
Its the equivalent of going a 160 on a 4.0" R3/MC41/MC22/N300/VTR etc. for starters 15mm chicken strip on the side is a waste, this is why the heat goes, the tearing happens and a highside waiting to happen because If I lean one more degree that unused chicken strip which is parallel to the wheel is where the tyre is unworkable.-

Same bike but with 140 DR2 on 3.5" rim, (equivalent of 150 on R3), marginally better but still that mid corner tearing-

Does anyone notice the 150 'LOOKS narrower than the 140?
Does anyone see how the tyre is a nicer sharper shape, plenty of contact patch on the side, less in the niddle for better tip in, less rolling restance and higher performance.
The 150 looks worse the more you lean.


Why do I even respond to these sort of threads?
but if it keeps a new rider safer, smarter, and more money in their pocket to spend on better gear, a track day or rider training, then my work is done.

 

[t-rav_12]

Chicken strips (or pu$$y stripes, as they're more commonly referred to in the midwest) are merely a sign that you're not using the full capability of your tire. Why pay extra money for extra rubber if you have no intent (or skill level [not directing this at ANYBODY in particular; just mentioning]) to use it. I totally understand though, if some people are just going for "that look".

 

[Aufitt]

Refer to my signature.

 

[Aufitt]

You almost had credibility. Then you threw out the "more chickens strips than kfc" thing. And then you lost it all. The type of person that give a sh!t about chicken strips has zero business riding on the street. period.

Fiiinnee... in a couple weeks i'll order a 150 i guess.

OK what's wrong with my 140 DR2?

Smooth even wear, exhaust weld has ground away but still didn't run out of tyre.


S20 Evo going on next week CORRECT sizes as I don't have as much credibility as the Engineers that design the bits we rely on.


Im not the one fitting wide tyres to 'look' good,
Im all about the best me and my machine can be, and its a lower budget than most bikes on this forum,
500km old and ran 4 secs of the 300 lap record in the 4th session of the first track day.

 

[pattonme]

The BT-90 (now Pro) is a fantastic tire that comes in the 110/120 fronts and 140-160 rears. I love them. It works very nicely on the street too, just take it easy if it's below 40F but I've ridden them below freezing and they behave themselves. I run 28/28-30PSI on the track and I'm a beefy 250lbs.

Running a 150 or 160 isn't going to kill anybody outright even if they are clueless about chassis and suspension dynamics and setup. They might get a surprise though if they were counting on all that extra theoretical 'edge grip'. There really isn't much point going wider since there are perfectly good tires in the 140 size. If you're into the 'phat tire' look for some reason, well, you need counseling. ;-)

 

[expseeker]

Not going to quote everyone here, but I have a few responses to some of the above posts.

First, don't compare a bias ply tire to a radial. A radial tire is just going to handle better because of how it is constructed.

It really isn't a positive to have a Z rated tire. Z rating means the tire manufacturer has just tested the tire up to a certain speed (depending on where the Z is placed and if there is a Y or W at the end, it varies between 149 mph and 186 mph) and that the tire can withstand that speed for, at least, 10 minutes. Z rating also means the tire will have a stiffer construction, I don't mean rubber, but rather, the inner structure of the tire.



Having a Z rated tire on a R3 is like putting 275/35 tires on a Prius.

A 10mm change in the rear ride height can have a huge difference in handling of a bike. You change the geometry of the bike by raising or lowering either end of the bike. It was common practice to raise the front forks of an SV 5mm to 10mm in the triple clamps to get a better geometry for turn in. Rear shock height was then 13.75" - 14". Sure, you could go with something else, but those measurements really worked for most people. Not just on the track either.

The R3 doesn't have a 4.5" rim. It is 4". Putting a 160 on the rear will really pinch the tire and square it off. If you need to picture this, make a half moon shape with your hands by touching your fingertips together. Then slowly move your wrists together and watch what happens to the curve of your fingers. That is what is happening to a larger tire when you put it on a smaller rim.

As for the KTM having a 150 rear so it must be better because that bike was designed for the track holds no water. The KTM has a different geometry than the R3. That tire may just work better for that particular geometry set up. It doesn't mean it will also work for the R3. Plus, if you have ever visited the RC390 forums, you will see some of the racers switching to the 140 for better turn in on the corners.

If you really need proof that bigger isn't always better, just look at the guys running Moto 3 in Moto GP. Many times those guys are carrying more corner speed than the guys on the big 1000cc 200+ hp bikes. Yet the Moto 3 tires are only 120 on the rear and 90 on the front! Remember, Moto 3 bikes have more HP than the R3, yet those guys are almost dragging their elbows during races.

I guess if you want to throw your money away on bigger tires go for it. I will stick with the 110/140.

Sorry for the rant. >

you are right and the motorbike physical explanation is- if you have a thinner tire you dont lean as many angles as if you would be at same speed with a bigger tire.

so you can take corner with higher speed at same leaning angle.

 

[Gravian]

Figured I'd start a thread so other people can report back what they find using a 120 front and 150 or 160 rear.

I can confirm a 160/60 will fit no problem, which opens up a lot more options for super sticky race rubber and longer lasting sport touring rubber. I won't road test until I get a new set, so hopefully the handling will still be OK.

Are you still going strong with the 160 rear tire?? If so I will definitly change.. Any other opinions?

 

[FangShui]

Good to keep this in mind....

http://www.sportrider.com/does-size-matter

Bigger tire will be for looks only. The profile will be different than was designed for the R3, it will be much heavier (unsprung weight issues), and will handle differently. Will probably cause greater inaccuracy in the speedo reading, as well.

 

[mgfchapin]

Are you still going strong with the 160 rear tire?? If so I will definitly change.. Any other opinions?

As I suspected, not really worth the extra weight and handling detriment for track riding. I've been riding on Pirelli Rosso II's in the stock sizes and I absolutely love them. I'm on the faster end of advanced group at the track and they were totally planted all day. The only limitation was the stock pegs dragging everywhere.

If I were riding street only, I would probably go with a 160 to get Michelin Pilot Road 3's, but in my case I like the skinny profiles better.