180????

[blkpitbull]

Hahaha, heard that before???

Seriously though.

I have a thought/observation/question!

A guy at my work recently traded for a 2000 750 Kat. I was checking it out after work and notice the rear tire was a 180/55!! It was about wore out and he said it was put on new by the other owner and never had a problem. This was after I told him he really needed a smaller tire on there. We left and on my way home I thought, besides the bad handling, whats really so bad about a 180?? Apparantly this tire was fine for its life and didnt fall off, blow up or nothing. And has anyone heard of a 180 on a 98+ failing in any way that caused a rider to wreck. I havent. Just a thought, and I personally dont have a Kat anymore just thought about it and I personally cant think of anything wrong with it than the handling issue, inless anyone can show/give me proof of a 180 failure, bead seperating etc etc...... Please explain better, and not just the rims not wide enough excuse, cause I seen a 180 today that was put on new and didnt have a problem and Ive never heard of a problem


Go ahead Im listening!!!

[blkpitbull]

Anyone have anything?????

[steves]

It changes the contact patch profile of the tire. The CyberPoet has a write up on it over at his site I think... www.motorcycleanchor.com

Also, the wider tire can slip over the lip of the tiny rim...

[blkpitbull]

It changes the contact patch profile of the tire. The CyberPoet has a write up on it over at his site I think... www.motorcycleanchor.com

Also, the wider tire can slip over the lip of the tiny rim...

Great someone responded!!!

Granted I understand it changes the contact patch of the tire, which is the same reasone for the terrible handling!


Still how you say it can slip over the lip of the tiny rim when noone has heard of this happening?? Has it happened?? I dont want an argument just think its funny everyone preaches (I was quilty too) a 180, 170 is WAY unsafe when in reality no one can legitly tell of a seperation/crash story as a result of the tire coming off the rim!!!

[katanapr3]

I've seen it, 180 tire on a kat rim it doesn't look pretty but the guy said it ran fine. then again the kat had rash on both sides I guess that speak for it self.

[steves]

http://www.sportrider.com/tech/tires/146_0206_tire_size/

http://www.katriders.com/forums/viewtopic.php?t=7909

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.

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).

okay, so not neccesarily dangerous, but at the very least pointless.

[blkpitbull]

ah the reply I was looking for.

So not so much dangerous just no need for that big of a tire?!

[steves]

I'm not sure what exactly you are trying to get at? It could potentially be dangerous as it changes the handling characteristics of the machine.

[blkpitbull]

I'm not sure what exactly you are trying to get at? It could potentially be dangerous as it changes the handling characteristics of the machine.

Yeah but then you could say that going from a 120/70 to a 120/60 is "potentially" dangerous. Not quite as drastic BUT that change is very noticable.


Im talking about:

Technically a 180 is fine as long as you understand that it hurts handing. Im not sure I agree that I would call the change in handling dangerous, the person would get used to it?

Also its NOT a liability as far as coming off the rim or bead, cause aparantly its never happened.

So when someone comes on and asks about a 180 or whatever on their bike, everyone is under the assumtion that its a "fatal" mistake and is SO dangerous, when in fact its not that dangerous at all!

[steves]

Well, it could potentially be a fatal mistake... turning a normally docile bike into one that is "twitchy" could be a real problem.

Let's remember that neither the manufacturer of the machine or tire recommends one that big.

IMO it's a bigger risk than having a bike lowered.

[kwebbel]

Well, it could potentially be a fatal mistake... turning a normally docile bike into one that is "twitchy" could be a real problem.

Let's remember that neither the manufacturer of the machine or tire recommends one that big.

IMO it's a bigger risk than having a bike lowered.

If I do look at the tables some manufacturers publish regarding rimwidths they'll allways give a certain range in rimwidth they consider appropriate (SURE those guys and gals know best) AND a recommended rimwidth for every type and size tyre.
Well I couldn't find any tyremanufacturer untill now telling it's ok to mount a 180 on a 4.5" rim (even Avon doesn't) max size though not recommended they will all tell is 170/60.
Just one question..
WHY in HELL would someone put him/herself at risk just for at most half an inch more (if so)?

[grumpyoldgit]

IMO it's a bigger risk than having a bike lowered.

Risk from lowering the bike? Please illuminate.

[blkpitbull]

Well, it could potentially be a fatal mistake... turning a normally docile bike into one that is "twitchy" could be a real problem.

Let's remember that neither the manufacturer of the machine or tire recommends one that big.

IMO it's a bigger risk than having a bike lowered.

If I do look at the tables some manufacturers publish regarding rimwidths they'll allways give a certain range in rimwidth they consider appropriate (SURE those guys and gals know best) AND a recommended rimwidth for every type and size tyre.
Well I couldn't find any tyremanufacturer untill now telling it's ok to mount a 180 on a 4.5" rim (even Avon doesn't) max size though not recommended they will all tell is 170/60.
Just one question..
WHY in HELL would someone put him/herself at risk just for at most half an inch more (if so)?

Im not sure why someone would risk negative handling just to get a phat tire look. BUT I have heard from a good source that he went from a 150/70, 120/70 stock tire setup and went to a 180/55,120/60 setup and said the difference is noticable but nothing dangerous, just took a few miles to get used to. But Im looking for definitive proof that a 180 has failed, (not cause of wear to the cord, or burnouts) but cause it was on a 4.5 kat rim. Ive never heard it.

I dont see lowering a bike dangerous myself!

[InsaneSpeedAddict]

IMO it's a bigger risk than having a bike lowered.

Ohh yeah it's very dangerous if someone hit their peg on the ground because they have a lowered bike blkpitbull, haha !! lol

Personally i'll put the hand on a Z6 ReadTec 170/60 Metz(I don't know if you guys say that in english, let me know) as soon as my Michelin Pilot 150/70 will be worn and I'll give you news blkpitbull about the Z6.

BTW, does anybody have good front tire to go with my rear Z6 tire ?

Cheeers

[steves]

IMO it's a bigger risk than having a bike lowered.

Risk from lowering the bike? Please illuminate.

Lowering the bike changes the steering geometry. Most people swap the dog bones, and never bother to worry about the forks... and the bikes handle like crap.