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Discussion Starter #1
I'm still breaking in my "new" '02 ZX-6R, so this may be a bit premature. The stock tires seem a bit nervous, espeically over groved pavement. I'm running them at stock pressure, which is quite a bit higher than stock pressure on my old YZF (36/42 vs. 33/36). Curious if this is a common perception.

I liked the BT010's I used on the YZF and will probably replace the 207's when its time. But I'd also like to try the BT012s and Pirelli's Diablo Corsa. I haven't seen these tires in the 120/65 size that comes stock on the ZX. I know they are available in 120/70, so I might try that size. So has anybody put 120/70s on the bike. Curious how it affected handling and whether you made any geometry changes to compensate.

Thanks,

BS
 

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Try a search... It's been discussed before.

Some just throw the 120/70 on and run with it, some adjust the ride height of the front end accordingly. (The difference between 120/65 and 120/70 is 10 millimeters in overall tire diameter and thus height.) Either way it's been done before and will work. If you don't change the front end for the new ride height the bike would turn-in slower, not a big deal for most street riders.

Now that the Dunlop 207's are done ... I've switched to Bridgestone BT010's and so far they seem grrrrrreat!
 

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I run 120/70 on my 02, works great. I rode maybe 3000km without any geometry changes and can't say the difference is that big from stock, noticeable, but not big.

I'm now 6mm up in the back with stiff suspension and I love it. Err, I mean the bike is 6mm up in the back [:eek:)]. For the track I'll be trying 10mm and/or more next season.

So when you do go for the 120/70 tire, I recommend to up the rear or if you're short, lower the front. I didn't want to lower the front because the bike doesn't have that much ground clearance.

But then again, what do I know[:eek:)]
 

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I had a set of D208's on my '02. I used the 120/70 tire size in the front, and never changed a thing. Just threw 'em on and gave 'er the big onion.

Hell, I got my knee down on those tires. So, I can't complain about anything.
 

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Originally posted by BSHAP

(The difference between 120/65 and 120/70 is 10 millimeters in overall tire diameter and thus height.)
That is not quite right.

Given the same construction, the 120/70 tire is 6 mm taller in section height. You can maintain stock ride height by raising the forks that much through the triple clamps. The tire height includes the sections above and below the axle, so the 120/70 tire stands 12 mm taller.

But the section height of a 120/70 tire varies with brand and even construction. If you are changing brands, you maintain the stock ride height by measuring the circumference. To learn how, check out sportrider.com. You can also just ride the new ride height and see if you like it.

Thirty-six front and 32 rear are the max recommended pressures for the max load with a passenger. You may like the handling better at 34 front and 36 rear.
 

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Oh a cheap shot from the Boy... [:M60]

That's the last time I generalize, guess I'll have to be more specific. [:p]

Honestly I didn't even bother really thinking about it as I just went by what Ryan told me ... when we were dicussing tires after you lifted what was reserved for me! [}:)]

However, as everyone knows in 120/65/ yada yada, the 65 is the side wall's percentage of the tire width's 120.

120 mm x 65 = 78, 120 mm x 70 = 84, 84 - 78 = 6 mm (x 2) = 12 mm
Happy now?? [:M7]
 

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Discussion Starter #9
Originally posted by Rob Lee

Thirty-six front and 32 rear are the max recommended pressures for the max load with a passenger. You may like the handling better at 34 front and 36 rear.
I tried that last night. Make's quite a dramatic difference in feel. Bike feels a bit more planted (and pehaps a bit sluggish), but I still get a bit of odd, skittish feedback. I'm not sure I'm there yet, I may need to tweek the suspension a bit. Any suggestions there? I'm interested in whether folks generally feel it is necessary to upgrade the suspension (a no-brainer for my SV) or whether the stock equipment can be manipulated to suit. (This is for street riding but the healthy, active Sunday morning type, not the commute.)

Thanks for your thoughts.

BS
 

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The stock suspension on 2000 to 2002 bike is quite good. You can read more about it at traxxion.com.

Set the rider sag to 38 mm in front and 30 mm in back. Then, use the damping settings from the article or your tuner. Do not waste your time turning the damping adjusters before you set the sag.

If you still do not like the handling, consider uprating the suspension.
 

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Discussion Starter #11
I'm surprised you would suggest such a difference between the front sag and the rear sag. Would you explain please.

BS
 

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The numbers need not be the same; that is a common misconception. They come from the guideline that a sportbike handles best when the front suspension sags at about one-third of its travel and the rear suspension at about one-fourth of its travel.

The two ends of your bike are loaded quite differently. To properly cope with that difference, the front springs rate at less than 1 kg/mm, and the rear spring rates closer to 10 kg/mm.

Many suspension tuners suggest 35 to 40 mm rider sag in front, and 25 to 30 mm in back. If you check out the traxxion.com article, you will see just that range. I suggested the numbers I would use for your application, sport riding on the road.
 
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