Tire size choice

Aloha guys. I have bit of a problem and need to find out if it's possible.

Now, before I get into question, problem is mostly because of where I live. Shipping is/are crazy expensive. Specially if the shipper only use Fedex or UPS. USPS Priority is not too far behind in this situation. So as much as possible, I go with free shipping. And because of this, my only choice right now is buy tires from Revzilla. So my question.

I had no problem finding front tire, found some Shinko 777 for 100/90/19 so I'll skip that one. My problem is rear. My wheel size is 18 x 2.15. Stock tire should be 120/90/18, but can't find any that I want. I found either 120/80/18 or 130/90/18. Now, I know 130 will fit because the previous owner (some 20+ years ago) put Dunlop 130/90/18 which I took it off recently. but the profile of tire, specially in the middle was kinda flat, for lack of a better word, kinda look like skinny car tire. which is why I'm asking.

I'm still looking for 120, but in case I can't find any, should I go with 120/80 or 130/90? BTW, brand of tire will be different at front and rear. I know I should stick to same brand, but like I said, can't find any unless I either pay for the tire (which are very expensive) or go with the tires I don't want.

Any advise?

Oh, and by the way, don't believe that free shipping thingy unless you actually put the item in the cart and do the check-out. My heart almost stop and came out from my mouth.

I would be inclined to use the 120/80 if it is very similar to the front tire.

Ojisan rider post=847183My wheel size is 18 x 2.15. Stock tire should be 120/90/18,

should I go with 120/80 or 130/90? 

I would definitely go with the 120/80-18.  The width will be similar to the stock 120/90-18, but the overall diameter will be a bit smaller.  With the 130/90, it will be both wider and taller than the stock tire.

According to the tire manufacturers, a 120 is a bit wide for a 2.15" wheel, even though most of us run a 120 on our KZs.  The Avon RoadRider mk2 and Bridgestone BT45 and BT46 all call out a 2.5" minimum wheel width, and are all measured on a 2.75" rim. 

I tried to run a 130 on my bike and it chewed up the inside of my chain guard and also the tire side wall cracked quickly which may be, I'm guessing, due to the stress of squeezing onto a thin rim.  

Another size option might be a 4.00-18.  Depending on the manufacturer, these are often pretty close to a 120/90.  The RR2 and BT46 list 116 width, while the BT45 lists 119mm width.  But the 4.00 might actually be closer in size to the 120 than you think.  As I mentioned, the 120s seem to typically be measured on a 2.75" rim, while the 4.00-18 are measured on a 2.5" (Avon and BT46) or 2.15" (BT45).  A 120 squeezed onto a 2.15" instead of 2.75" might actually end up narrower than the BT45 4.00-18, advertised as 119 on a 2.15".

Yet another thing to watch out for is the size "number" vs the actual size.  A 120 is not always a 120.  For example, the RR2 120/80-18 is specified as 120, but the 120/90-18 is specified as 129mm.  While the BT46 120/90-18 is 119, and the 130/90-18 is 136.  The RR2 120/90-18 is 10mm wider than the same size BT46.  This can make a big different if you're close to the clearance limits for you chain guard or front fender or whatever.


www.avontyres.com/en-us/tyres/roadrider-mkii#page-2
www.bridgestone.com/products/motorcycle_...oducts/detail/pr176/
www.bridgestone.com/products/motorcycle_...oducts/detail/pr015/
 

Thanks for the advice guys.

Found some pictures of my old tire. As I mentioned, the tire were put on by previous owner some 20+ back, and just recently was taken off the wheel to have the wheels painted. At least for me, I had no problem of tire hitting anything when I was riding this thing.

Just so that you guys don't get heart-attack looking at pictures above, wheels have been powder-coated since.

Anyway, search for the right tire continues.

I've always run 130/90-18's with no issues.  The only flat spots on my tires are the one I created (drag racing).

wrote:

I've always run 130/90-18's with no issues.  The only flat spots on my tires are the one I created (drag racing).

       Thanks Trout. If I fail to locate any 120/90, At least I have a option to go with 130. But much as possible, I want to stick to stock size for many reason, for now.
 

A 130 on a 2.15" wheel is way to wide.  Like a fat girl in a too small bikini.  

I just l ordered a set of roadrider MK2 tires from this site:

  www.americanmototire.com/

They were much cheaper than other sites (~$40 per tire), the shipping was free, and they arrived on my porch 4 days later.

wrote:

A 130 on a 2.15" wheel is way to wide.  Like a fat girl in a too small bikini.  



 

I agree!  I used 130 tires on my KZ650 for several years, but the narrow rim deformed the shape of the tire.  I've been using 120 tires for the past 12 years and have found that they put as much (or more) tread on the ground as the 130 tires because their profile is not deformed.  Ed

wrote:

A 130 on a 2.15" wheel is way to wide.  Like a fat girl in a too small bikini.  

     Why? What's wrong with fat girl in small bikini?

Joke aside, Yes, I know. My 130 tire didn't look right. It as kinda flat at the middle. Reason why I'm still searching for 120's. Fitting 130 will be my last option.

DOHC, I've already checked the site and it's not free shipping. Like most places, they're free to 48 states. Unfortunately, we are not included in that 48.

Ed, I'm not looking for bigger tire. It's the choice I'm faced with. Reason why I'm still looking.

In any case, thanks for the concern. But I'm not ready to purchase the tire yet. Still looking for that 120/90.....................
 

Just went to Revzilla to order some tires but Alas, no shipping to Hawaii. I put the tire(s) into shopping cart and it let me show the shipping said it's free, but when you actually go to checkout, it said it can't ship to my address. No, Even if I wanted to pay for shipping, it wouldn't let me. But at the same time, god knows how much the shipping will be............................ Probably have to sell one of my kidney to pay for the shipping.

Anyway, Once again, it's what's available for me. Not what I want. Price I have to pay living in paradise (which not too much of a paradise any more. Trust me and those of you who used to live here, like was here because of your service, it's not the same anymore).

Bridgestone makes the BT46 Battlax in 120/80-18. DennisKirk.com has them but I don't know if they ship to HI.

I was stationed on O'ahu a long time ago - sorry to hear it's not as nice as it once was.