What would a 120/70/17 do to my handling?

[Adam R]

I recently bought some Pirelli Supercorsas in a package deal.  Turns out the front tire is a 120/70.  It came on a GS500 rim and I know it's supposed to fit.  But will the tire negatively affect the bikes handling?  Since I am soon heading to a track day, it's important that I not compromise handling.


Thanks

Adam

[Lars]

I think turning into the corner will go a bit slower. But the GS is normally extremely flickable so I think that won't be a problem.

[yamahonkawazuki]

should be no prob., just maybe take it easy till you get used to it.

[Adam R]

I've looked into this on some other forums and it seems that a bunch of people have raced GS500s with 120s, but people have better things to say about the 110/70.  I guess I'll find out.


Adam

[JBix]

It depends mostly on the profile of the tire.  Since the stocker is a 110/70, and you'd be putting on a 120/70, the profile would be a wider curve, so it's safe to assume the bike would turn in noticably slower.  Not necessarily too much to deal with, but something you'd have to get used to.  It may not change handling any more than simply switching brands.  If you do it, write about how much handling is changed for a reference.

[JBix]

In short, it shouldn't compromise handling, just a slight change.

[Adam R]

I found a deal on a Pirelli Corsa 110/70 front, so I'm not going to try this experiment.  I can post some info that I've acquired about it from exchanging a couple emails:

From a WERA racer:
"The rim on the GS is a 3" rim which calls for a 110 tire.
Squeezing a wider tire on will make the bike handle wrong. Might slow
it down, might add some head shake ... hard to predict. You could lower
the front (prob about 2 or 4mm) to account for the height gain but the tire
profile is going to be fubar."

From Kevin C:
"I never tried running wider tires on the stock rims. I have seen too
many bikes crash at high speeds for strange reasons to put tires on a rim
that is narrower than they spec for a tire. There will be less support for the
tire and the sidewalls are at a steeper angle. And when you are starting to
race, there are enough issues to figure out without possibly having your
tires do strange things.  People seem to do it successfully though, so it is up to you.

From WERA (race) forun:
I used the 110 front and 150 rear. Tried a 120 front but the 110
turns better. Never had the option to use anything other than
150 rear. I like the Pirellis and Michelins.

The stock front rim is a 3" it needs a 110/70-17. but I guess you could use a 120 if you have something to compensate for and you believe bigger is better, not just bigger.
The rear needs a 140, but some prefer the 150. both are fine, but I think the 140 fits the rim better.

Two guys on the WERA forum used 120fronts, 150 rears and had no complaints.

Bob B says"
I've run the pirelli super corsas in the past. I did have the 120 front
and 150 rear.
It may have a slight effect on handling, but nothing to worry about.

In my case, I decided to get a Pirelli 110 because I would be mixing two different manufacturers in addition to the 120 size issues.  Since this will be my first track day coming up, I don't want to be worrying about my tires.

Adam

[JohNLA]

Let us know how it goes.

[J banning]

I found a deal on a Pirelli Corsa 110/70 front, so I'm not going to try this experiment.  I can post some info that I've acquired about it from exchanging a couple emails:

From a WERA racer:
"The rim on the GS is a 3" rim which calls for a 110 tire.
Squeezing a wider tire on will make the bike handle wrong. Might slow
it down, might add some head shake ... hard to predict. You could lower
the front (prob about 2 or 4mm) to account for the height gain but the tire
profile is going to be fubar."

Old thread, but still good info. Thanks!


From Kevin C:
"I never tried running wider tires on the stock rims. I have seen too
many bikes crash at high speeds for strange reasons to put tires on a rim
that is narrower than they spec for a tire. There will be less support for the
tire and the sidewalls are at a steeper angle. And when you are starting to
race, there are enough issues to figure out without possibly having your
tires do strange things.  People seem to do it successfully though, so it is up to you.

From WERA (race) forun:
I used the 110 front and 150 rear. Tried a 120 front but the 110
turns better. Never had the option to use anything other than
150 rear. I like the Pirellis and Michelins.

The stock front rim is a 3" it needs a 110/70-17. but I guess you could use a 120 if you have something to compensate for and you believe bigger is better, not just bigger.
The rear needs a 140, but some prefer the 150. both are fine, but I think the 140 fits the rim better.

Two guys on the WERA forum used 120fronts, 150 rears and had no complaints.

Bob B says"
I've run the pirelli super corsas in the past. I did have the 120 front
and 150 rear.
It may have a slight effect on handling, but nothing to worry about.

In my case, I decided to get a Pirelli 110 because I would be mixing two different manufacturers in addition to the 120 size issues.  Since this will be my first track day coming up, I don't want to be worrying about my tires.

Adam