I've never seen this posted, huh?

[QuickKat]

Okay maybe a couple times, but I'm having a hard time find the nitty.
What is the widest tire you can put on a 03 600 rear and
what are the pro's and con's of doing this. I apologize for admiting that I
currently have macadams.

[WildKat]

Check out the rolling stock forums.. its been discussed many times. Some say dont go any bigger than 150..some say 160, and some will go 170. Really all depends on what your comfortable w/ .

IMO, 160 is more than sufficient to do the job. Pilots, Metz, are 2 popular tires for kats.

It's a huge change when you jump from an aftermarket tire, from the macadams for sure, and u'll need to get used to not only the improved handling because the tires are better..but also the difference because they are bigger.

[md86]

20X2.75 , but I prefer the 20X1.75's personally . Makes the old Diamondback turn a little better ... what ?

[Black_peter]

20X2.75 , but I prefer the 20X1.75's personally . Makes the old Diamondback turn a little better ... :dunno what ?

Nice!!

Pilots, Metz, are 2 popular tires for kats.

You mean popular cures for Macadams.....

[The CyberPoet]

The rear rim on the 98+ is built to take a 150/70ZR17. Normally you can go up one size by decreasing the sidewall height 10% (160/60ZR17), which gives you an advantage in dry grip, but increases tendency to hydroplane (more surface contact, same weight = less loading per square inch) and will force the tire to deform slightly in response (normally making run a bit hotter than the stock sized tire). The wider tire will also reduce the handling sharpness of the bike compared to a narrower tire with the same tread composite, arc design and tread design (can't compare a 150 Macadam to a 160 Pirelli or a 150 Metzeler -- the Pirelli and Metzeler are just head & shoulders above and have both better tread composites and triple-arc radius designs).

Once you go past that one step-up, you are traditionally setting the angle of the mounting lip on the tire at hard enough of an angle that it can provide stress issues at the first bend above the mounting flange of the rim. The tire also has to distort to compensate for being pulled so tightly at the center, so the arc deforms to compensate, resulting in elevated heat at the carcass. Both of these issue can lead to failure, although it tends to be infrequent. A few companies manufacture wide (170 - 180) tires specifically designed to mount to a 4.5" mounting flange size (the size of the 98+ kats' rear wheel).

Here's some more tire stuff I've written gathered together from other threads (so I don't have to re-write it -- and yes, I know some of it repeats):

The stock Michelin Macadam has an gradual arc shape (single apex) that is very poor for handling. Suzuki uses it for a couple reasons -- it's cheap for them in bulk, and it discourages young bucks who have this as their first bike from pushing it beyond their limits (as evidenced by those of you saying you felt as if the back end would give out). This has zero to do with the fact that it's a 150/70ZR17, and everything to do with the fact that it's a Macadam (commonly called Crap-a-damns around here).

Moving to a Metzeler Z6 all around (120/70ZR17 front, 150/70ZR17 rear) will fix this issue, as will switching out to Pirelli Diablos (where you have to use a 160/60ZR17 rear because it's not offered in a 150/70ZR17) or Pirelli Diablo Stradas. A pair of Z6's will run you right around $186 - $220 mail order; you may be able to find a local price in that ballpark after you factor in mounting costs (many dealers mount tires they sell cheaper than they mount tires from elsewhere, since they've made their money on the tire as well).

As for running mismatched tires -- don't do it. There are several reasons, including:
The front tire "sweeps" for the rear's tread pattern. Mismatched tread patterns will not permit correct sweeping and may cost you a loss of rear traction on water, sand, etc.
The arc design between the tires is designed to work together, so that as the bike leans, both tires are offering the same surface to the ground in unison rather than exerting stress through the frame due to an imbalance in angles (which again can cause loss of traction).

If you feel the stock tires aren't up to snuff (they aren't), replace them and sell the existing ones on eBay to help offset the cost -- someone will want them.

KNOW THIS:
Different manufacturers' specific tires will expand different amounts once mounted and heated/cooled, from as little as 2% on some street tires to as much as 25% on some race tires. Most street tires will expand about 4 - 7%.
When you mount a 160 into a rim designed for a 150, the shape is distorted some, pushing the center arc of the tire outwards further because of the pressure on the sidewalls from the mounting flange angle. This increases the effective circumference above what you would get mounting the same 160 on a rim intended for a 160, and helps decrease the amount of change from a 150. On the other hand, this change in shape also causes the tire to build more heat, resulting in low lifespans than would be the case with the same tire mounted on the "ideal" rim for it.
Pretty much all manufacturers simply lie in their measurements. Theoretically, a Metzeler Z6 150/70ZR17 for example should have a sidewall measurement of approximately 105mm (70% of 150mm). The truth is that it will act as if it were a 150/70ZR17 and safely mount where a 150/70ZR17 will mount. In reality, the real-world sidewall measurement on a Z6 in a 150/70 is closer to 69mm (of which about 50mm is exposed on a 98+ Kat rim -- measure it yourself!), and the full distance from the inner lip to the peak of the center arc is only about 97mm once mounted. This would mean that their claimed 150/70ZR17 is actually closer to a 150/46ZR17

The arc face (edge to edge across the surface) is 190.5mm on a 159/70ZR17 Metzeler Z6. Measured by the proper sizing method, that makes the tire a 159/61ZR17 in reality. Now try to reconcile that with the fact that it's labeled a 150/70ZR17 :P

Avon (a subdivision of Cooper Tires) makes a 170 that will fit the 4.5" rim of the 98+ Kats without modification.

KNOW THIS:
Wider tires are only better if you need them to overcome the amount of horsepower being laid down; narrower tires handle more sharply, steer better, cut water and dirt better (i.e. avoiding hydroplaning), and make the thottle & brakes more responsive (as there is less rotational mass to have to spin up & down). Odds are you will not get a positive benefit from moving to a 170 width tire unless your bike is putting out 90+ rearwheel horses (although unless you compare new tire to new tire, you'll never know for sure).

To read tires, it goes like this:

150/70ZR17 (62W)

Where:
150 is the tire's width left to right across the tread area in millimeters;
70 is the sidewall height as a percentage of the first number (i.e. - in this example 70% of 150mm = 105mm);
ZR is the speed rating (Z) and if required the radial (R) or Bias (B) requirement;
17 is the wheel diameter in inches;
(62W) is the weight rating (62) and any special manufacturer codes (W is often "weight", but they could also have "RR" for road racing only, etc).

THINGS TO KNOW:
1. Bias (non-radial) tires generally are 1/4 wider at each lip than comparable-sized radials because of how the lip is formed;
2. Front and rear tire treads and crowns are designed to work together to sweep water or loose debris out of the way; the front tire clears for the rear tire's tread pattern, and is the reason manufacturers all recommend using the same brand & model tires front and rear together as a pair.
3. Front and rear crown apex designs are designed to work together to provide a consistant lean angle for the bike, to reduce unnessary flexing from mis-matched lean angles; this is the other primary reason that all tire manufacturers recommend matching brand & model front & rear tires.
4. Of all the manufacturers, only Dunlop permits patch of punctured tires, and then only certain models of rear tires, single patch, and when patched, the speed rating drops to 70 mph.
5. All tires "grow". Typical street tires grow in size about 5% - 8% during the first 10 days of ownership from being under pressure and heating cycles; race tires grow even further (as much as 22%).

i've got a 160/60 rear tire on my pre98, and i've read this is bad, why is that?

The reason it's normally considered "bad" is really to say it's "not perfectly safe" because the width of the tire on the stock pre-98 rear rim causes a less than ideal mating between the rim flanges and the tire bead lip, and exerts excess stresses onto the junction between the tire bead reinforcement and the sidewall (as well as deforming the actual arc radius of the tire, causing it to run hotter than intended). Most riders who try it may like it, but are missing the fact that the squeeze is making the tire act more like a 150/70 than a 160/60. Switching rear rims to a 98+ Kat rim will set everything right again, since the 98+ rim is wide enough to take a 160 safely without too much distortion.

Here's my age old recommendations, based on actual back-to-back tire swaps on late model katana's (one set a week, a few hundred miles inbetween):

1. If you primarily rail, live in a dry area (think desert, etc) and wet-grip isn't critical (buy dry-grip is), get yourself a set of Pirelli Diablos. Best dry surface grip and great triple-apex design. For street, go 150/70ZR17. For primarily track use, go 160/60ZR17.

2. If you primarily commute, tour, engage in all-weather riding or high-speed highway mile eating, get yourself a set of Metzeler Z4's or their follow-on replacements, the Z6 Roadtechs. They have a good triple-apex design, about 95% of the dry-weather grip of the diablo's, about 140 - 200% of the wet-weather grip, and quite a bit longer lifespan in them. Go 150/70ZR17 for best handling.

3. If you for some reason insist on having the biggest, widest damn tires you can squeeze in (which negatively impacts handling, but it seems to be bling-bling right now), Avon, a Cooper Tire subsidiary, makes a 170 that will fit the stock rear rim of the 98+ Kats. They also have a limited road-hazard warrantee in Canada & the UK & the USA (covers the tire, not the labor, valid for the first 3.5mm of tread depth wear).

4. Or, if you have the $$ and time to try it, do what I did and simply order yourself a whole variety of suitable tires (you can get quantity discounts this way, both from the vendor and from the local shop that will install them each week). Compare them back-to-back and sell the barely used ones on eBay -- if you shop wisely, you'll make back every penny you spent on tires when you resell them (at least I did). Keep the ones you like the best
I compared: stock Macadam 90x's, Dunlop 205's & 207's, Metzeler Z4's, Pirelli's Diablo's, Chen-Shins (never again!), plus rode other people's Avons and Bridgestones during that same timeframe. You can pick your own tires for your own comparo...

Notes:
Chen-Shins, aka Barracuda's, aka JC Whitney no-name house-brand, aka Maxxums: the crappiest, cheapest tires ever. Use only if you are showing threads and are in starving college student mode; expect no handling or stopping capabilities. Worst tire I've ever tried.
Macadam 90x: Broad, single apex design makes for wallowy, slow handling but decent breaking performance. Ran into scalloping, uneven tire wear. I suspect high road-surface temps in Florida, combined with my highspeed (100 mph+) style of riding played into the tire tread wearing unevenly.
Dunlop 205's & 207's: Dual-apex design, better than the Macadams, but advantages wore away within 1200 miles. Same type of uneven tire wear as the Macadams. I suspect high road-surface temps in Florida, combined with my highspeed (100 mph+) style of riding played into the tire tread wearing unevenly.
Pirelli Diablos: Triple-apex design, superb dry-weather grip, unfortunately grip nose-dives on wet surfaces, especially at first mist and in torrential downpours.
Metzeler Z4's: My tire of choice; been through 3 sets of them so far (almost 30k miles) between two late model Kat 600's. Triple-apex design, more grip than a stock Kat 600 can break loose railing as hard as possible; hyper-reliable grip in the rain (which we get a ton of in Florida). I liked the fact that when locked, the rear bunny-hops a couple times before sliding out...
Metzeler Z6's: I haven't ridden them yet, but Metzeler's engineers tell me that they are the Z4's with a smaller initial bead compound (10% more grip in the dry, 18% more in the wet, and 8% longer lifespan) and a modified tread-pattern for supposedly better heat & water dissipation. Others here on KP have tried them -- all have loved them.
Avons: Seem to be the Canadian tire of choice. Not sure why, but I suspect that road-hazard warrantee plays into it. I liked them, but they still weren't quite up to the spec of the Pirelli's and Metzelers, plus I got an uneasy feeling about the belt construction (can't recall the exact why's anymore -- perhaps bias tires?)...
Bridgestones: Longlasting, single and double-apex designs, but took quite a while to warm up and never were as grippy as the Pirelli's and Metzeler's.

TIPS:

1. When shopping for tires online, always include shipping costs into your calculations. Many firms low-ball tires and then make it up on shipping. I've bought my tires (except for emergency replacements) from chaparral racing ( http://www.chaparral-racing.com/ ); their site isn't always up to date on what they have in stock (call them), but they've always come through cheapest with what I wanted. Other standard sources include DennisKirk. Ask around about reputations -- some standard sources have bad ones when it comes to fulfillment.

2. Double-check with the manufacturer on recommended tire pressure on your bike with a specific tire. Not all tires are supposed to run at the same pressures as the OEM Macadams (the Metzlers and Pirelli's for example run 34 front, 38 rear rather than 32/36).

3. KNOW THIS: Pirelli motorcycle tires are built in Metzeler's factories. Metzeler is the only motorcycle-only tire manufacturer in the world.

4. Balancing is critical. Get the tires balanced at time of install. Also insist the valve is replaced at that time for your own safety.

5. Be cautious: depending on where you live, local dealers & shops may not be willing to mount tires acquired from elsewhere, or may charge an arm & a leg to mount tires they didn't sell you. Shop around for mounting prices before you buy the tires.

6. Most dealerships & shops will charge you half-rate or less if you bring them the wheels already off the bike (saves their mechanic's time). Ask about it.

More next post.
Cheers,
=-= The CyberPoet

[The CyberPoet]

Now it would seem the latest rage is to shoe-horn the widest tire possible onto the bike, because this is what is happening on the R6/R1/GSXR600/GSXR1k/etc. The fact of the matter is that these bike's handling is designed around this fact (or in-spite of it, with extremely aggressive headstock angles to compensate). They would still handle better with narrower tires, but then the manufacturers would open themselves up to a ton of lawsuits from street riders who lost the rear end traction by getting on the gas while coming out of a corner. Thus, it's a trade off between sharper handling and the ability to sucessfully transmit power to the ground without loosing the traction in the rear excessively.

On a bike like the typical Kat 600 or 750, there simply isn't the horse power to overwhelm the stock tire size coming out of the corner with a good compound on there (this may change if you've modded heavily, changed gearing radically, or dropped in a bigger engine/etc).

When you look at race bikes, they use the narrowest tire they can readily get away with, because narrower tires handle better -- they weigh less (so they brake easier, accelerate faster and change direction quicker), and their arc shapes are sharper (making it easier to drop the bike into the turn).

Cheers
=-= The CyberPoet

[medic_rider]

i'm getting a new rear this week, right now, the way it was when i bought it there is a 180/55/17 mich pilot on it.... goin back to a 150...maybe 160

updated.. got front and rear tires on today, mich pilots, stock sizes all i can say is wow. the bike handles sooooo much better now its like a completely different bike, took about 30kms to get used to em but now its all good