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Discussion Starter · #1 ·
So beginning of the riding season I noticed my rear tire was completely shot. Being new to motorcycles, and completely broke I did some research and ordered a Shinko 230 Tour Master. Now I have put quite a few miles on the bike, and my front is going bad. I was going to throw another Shinko on it but turns out they don't make the correct size for the front. I also realized that the guy down at the motorcycle shop convinced me to put on a 120/90V 18 on the rear when stock is a 100/90 18. Now I am wondering if that is a bad thing? I still do not really have enough to buy two tires, and I am kinda stuck as to what to do about this. I can go with a Shinko 100/80 on the front, but stock is 100/90. Will I feel a major difference? I am worried about screwing up the handling more than I already have.
PLEASE HELP!
 

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Littering And...........
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Well between 100 and 120 it's just wider. So as long as it fits, doesn't rub on anything on the bike itself then it should be fine.

And the 90-80 just adjusts the height of the tire by 10mm.

100 / 90 / 18

Width Height Wheel Dia.

Mm Mm In

And height is from wall size if the tire.

I'm not sure of the exact specifics but that's the gist of it.

And the height of the wall on the front is only going to affect how close to the fender it is, and maybe the speedometer if its not driven off the front wheel.

Hope this helps a little.
 

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Discussion Starter · #3 ·
It does help a little. Do you think the handling will be much different if the tire is shorter? Also will it make me lean forward more?
 

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I cannot see tha handling changing very much with that wee diff' in size . I f youve had a good experiance with that wider rear so far that is good . Ive used 'Shinko' tires many times and in fact I just stucka 200 Shinko rear on me ZX9r after runing a real decent handling 190 'Metzler' so far so good :thumbsup:
 

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Bitches love Fighters
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your bike will turn in a bit faster. probably not noticeable at all actually.
 

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Master of Vril
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What he ^ said. You would only notice very small differences like that if you were on the track or very in tune with the bike. The wider rear should actually improve handling and lean angle. It's been proven that the back tire does just about all the steering when at deep lean angles. Moto GP bikes will actually unload the front suspension and even lift the front wheel slightly at extreme lean angles. Basically a wider contact patch will improve the grip in those situations.

This is kind of a rant but I like to rant sometimes.
 

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Discussion Starter · #8 ·
So if my rear tire is slightly wider, and my front tire is slightly smaller then it wont be a huge deal? I just want to make sure it is not dangerous, or going to make handling horrible.
 

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Discussion Starter · #10 ·
Sweet I will just go with that then. THANKS!
 
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Watch the world burn
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The wider rear should actually improve handling and lean angle.
False. Wider tires, especially on a skinnier rim, give you less of a contact patch, because the tire is slightly squished making the center higher. Plus wider tires take more effort to turn in. Not that the tiny difference there would be noticeable.

Also, there is no way to load the rear or bring the front end up mid turn during a hard lean. The only way to do that is by pegging the throttle, which would have a couple effects, none of them good in a turn. 1) the bike would want to straighten back up. You use the throttle to do this coming out of a turn. 2) the rear tire would slip, possibly causing a lowside, or highside if you freaked out and the tire regained traction. 3) it'd unsettle your suspension, either causing the rear to hop or possibly a tank slapper as the front end got light 4) it'd cause you to go wide off your line, into the wall, off the track, or into another rider.

Think about it: to steer, you must counter-steer. Only the front tire allows you to counter-steer. When coming into a turn (especially moto gp) you're heavy on the brakes, loading your front suspension, preparing for a turn. Clip-ons are popular for racing because they put more weight forward, enabling better handling.

Now, I have seen guys throttle hard out of a turn, leading into the next as it makes it easier to transition, rather than pulling the bike up and leaning it the other way. But thats not because it turns better, but transitions better between turns.

Twist of the wrist 2 is a good video on youtube that can explain riding and handling much better than I can.
 

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Master of Vril
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False. Wider tires, especially on a skinnier rim, give you less of a contact patch, because the tire is slightly squished making the center higher. Plus wider tires take more effort to turn in. Not that the tiny difference there would be noticeable.

Also, there is no way to load the rear or bring the front end up mid turn during a hard lean. The only way to do that is by pegging the throttle, which would have a couple effects, none of them good in a turn. 1) the bike would want to straighten back up. You use the throttle to do this coming out of a turn. 2) the rear tire would slip, possibly causing a lowside, or highside if you freaked out and the tire regained traction. 3) it'd unsettle your suspension, either causing the rear to hop or possibly a tank slapper as the front end got light 4) it'd cause you to go wide off your line, into the wall, off the track, or into another rider.

Think about it: to steer, you must counter-steer. Only the front tire allows you to counter-steer. When coming into a turn (especially moto gp) you're heavy on the brakes, loading your front suspension, preparing for a turn. Clip-ons are popular for racing because they put more weight forward, enabling better handling.

Now, I have seen guys throttle hard out of a turn, leading into the next as it makes it easier to transition, rather than pulling the bike up and leaning it the other way. But thats not because it turns better, but transitions better between turns.

Twist of the wrist 2 is a good video on youtube that can explain riding and handling much better than I can.
Sorry but your incorrect. That used to be the train of thought but now with slow motion camera technology it's been proven that the rear tire does all the steering mid turn to exit. They actually have footage of the front tire completely off the ground mid turn all the way out of the turn. The front tire aids in getting the bike down but once it's down the rear tire does the turning. I've watched them discuss and explain this exact fact during multiple races in Moto GP.
 
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