Hi I just bought a used CBR f2 for 1500 new rear tire that matches the specs on the fork tree, The rear tire being 160/60 ZR 17 (pilot power 2ct MIchellin) Almost brand new. The front tire is a Metzler (for whatever reason) and could use a replacing, it passes inspection, but barely. my question is It's 120/70 ZR 17 58W
but the specs on the bike say 120/60. On motorcycle superstore I want to purchase the front tire of michellin Pilot power 2ct but the options given are 120/60 ZR 17 or 120/70-17

Which one to buy? I know the second number has to do with aspect ratio so the height is half the width
the ZR is what ?
should i stick with what the previous owner was doing? or go with factory settings?
the rims are stock.

 

my two cents are: factory put out a spec for a reason. go with factory settings as a start then work from there. maybe he got a good deal on that tire or found it at a junkyard and said good enough. basically start at factory unless you have a very good idea of what YOU are doing and not what the guy before you did.

 

I just called the guy, he said he got the front tire for free and then lowered the front end half an inch to compensate...so now i have to find out how to raise the front half an inch lol
Thank you very much though for your input.

 

I got the tire combo special from cycle gear a while back. The size was front:120/70/17 Rear:180/55/17
I was not happy with the driving characteristics of the different size. turning was completely more agressive especially slower manuvers it seems like it wants to drop as soon as you'd geta couple of degrees of center.
And ever since i change my fairing to some chinese set, the front tire began rubbing on the fender. Oh and also I don't have a rear fender/chain protetor so I guess thats why the back tire barley fit.

 

Why would you put a 180 on that rim? of course it will handle squirly. Also tires often feel unstable at first but after a thousand miles or so break in and reach a sweet spot between stability, agileness and grip. Go wiith the 160/60 and 120/70. Lower the triple clamps 10 - 12 mm from stock to compensate for the taller tire and enjoy. Conti road attack 2 is a great choice. I just did what I described myself and let me tell you it transformed the bike into a more agile sure footed backroad blasting machine. If you need reference on what 10 - 12 mm from stock ask anyone with a stock front end setup to measure top of the fork tube to top of triple clamp distance, then add 10 mm for your setup with the 120/70. It is superior to the 120/60 in every way. A reason it may have came with a 120/60 back in the early 90s was at the time perhaps tire technology was not where it is today and the 120/70 possessed certain drawbacks at the time. Today tire technology is awesome and the 120/70 is the way to go for every type of riding. Main reason....More contact patch at aggressive lean angles.

 

120/70 is way better IMHO. You get more contact patch at the edge where it matters, and the front end has much better feel towards the edge with only that change. If you really wanna keep the geometry the same, you can drop the tubes 1/2" to compensate for the tire. This isn't going to sit badly on the F2's front wheel: it has a 3.5" wide front wheel like all modern sportbikes.

However, the F2 likes the rear to be jacked up and the front to stay high for some reason. The front fender will probably rub with the 120/70. If you're not pushing your bike, there's probably no reason to switch though.

 

Honda didn't choose 120/60/17 for their front tire, it was simply the best radial tire technology at the time.

Times have changed, and 120/70/17 is better. This however will require some geometry adjustment (fork lowering since the tire is taller) and it will throw off your speedo, which is mechanical so you can't really fix it.

 

When I raced F2s in the early-mid 90s,we always ran a 120/70. It handled better,period