Honda Motorcycles - FireBlades.org banner

1 - 10 of 10 Posts

·
Banned
Joined
·
694 Posts
Discussion Starter #1
I know the stock size is a 120/70/17 what I'm wandering is what the efeects on handling would be if I were to go with a 120/60/17. Has anyone done this or know specifics on the difference?
 

·
Registered
Joined
·
2,559 Posts
Based upon personel preference the 60 seems to slow down my turn and decrease the agility of my bike, I didn't like it. Felt fat and wallowed around on me. Depends on how hard you push the bike.
 

·
Registered
Joined
·
2,654 Posts
Based upon personel preference the 60 seems to slow down my turn and decrease the agility of my bike, I didn't like it. Felt fat and wallowed around on me. Depends on how hard you push the bike.

Not arguing since you have actually tried it but that is exactly backwards of what the effect should be and what I have always been told. A 120/60 has a lower sidewall height and gives an overall outside diameter that is almost 1" less than a 120/70. This effectively drops the front end and raises the rear end which would give a faster turn in. I would think that if you were to try the exact same tire from the same brand in both sizes that you might see the difference since tire profile between two brands can be different.

Outside diameter of Dunlop Qualifier 120/60-17 = 22.80"
Dunlop Qualifier 120/70-17 = 23.80"

I don't have any love for Dunlops but I would assume the difference is similar for all brands and I had the Dunlop chart handy.
 

·
Banned
Joined
·
694 Posts
Discussion Starter #5
Slickwill, I think you are correct but I have never tried it either, although when I had my F2 I had a buddy with the same bike. I bought mine with a 70 series tire on it his had the 60. His felt lighter and more nimble than mine. After trying different tires on my 929 I noticed a difference in feal with the same size different brand, so I wasn't sure wich was affecting my F2 the brand or the size, still trying to figure it out. Found some deals for 60 series on ebay, and was thinking about giving it a shot.
 

·
Banned
Joined
·
1,715 Posts
Some bikes come factory stock with a 120-60-17 ( Kawasaki ZX-6) the old ZX6 kawi keeps making/selling. It's geometry is set up to handle a 60 series tire.

I think most track day folks like the 70 series and there must be good reason. I'll stick with the 70. Hit a pothole with a 60 series and your going to feel it hard.
 

·
Registered
Joined
·
2,654 Posts
A one inch reduction in outside diameter would be equal to lowering the bike by 1/2" which is quite a bit in total handling characteristics.
 

·
Registered
Joined
·
2,654 Posts
Some bikes come factory stock with a 120-60-17 ( Kawasaki ZX-6) the old ZX6 kawi keeps making/selling. It's geometry is set up to handle a 60 series tire.

I think most track day folks like the 70 series and there must be good reason. I'll stick with the 70. Hit a pothole with a 60 series and your going to feel it hard.

I think a lot of the R6's came stock with the 60 series as well but also the rest of the setup was designed for it. In your case you could lower your forks by 1/2" in order to keep the same geometry or go down 1/4" and split the difference.

I feel like for everyday riding my bike turns in too quick and acts like it wants to tuck in so I could slow things down and be happy for normal riding. But when I was at the track one of the suspension techs said he could tell by the wear on my front tires in comparison to the wear on my rear tires that I needed to bring the rear up a little or lower the front just a little which would speed things up. I guess I just need to decide on whether I want a track or street set up.
 

·
Registered
Joined
·
2,559 Posts
When viewed in cross section the 60 series seemed to have a larger,(flatter radius) Than the 70 series does. It feels to me as if I have less center and more side contact patch with the 70's and the 70's don't feel like they are trying to roll me back up onto the center contact patch. With the 60's I worked to keep the bike leaned with the 70's it takes a little more to put them up on to the center of the tire. I'm about due for another set and am going to try the 2ct's I heard a rumor that they are going to have my 190 rear in a 60 series so I am interested to find out if this is so and give it a try
 
1 - 10 of 10 Posts
Top