The International CBX Owners Association

I found out that my 81X rear tire mysteriously developped a leak while sitting in the winter. As it is rather low on treads, I decided to replace it. It is a 130/80-18 BT45.
The BT45 also comes in a 140/80-18 and a 140/70-18. The application list recommends a 4" rim for 140/70.( ) Has anybody used the 140/70 on the rear of a Prolink? (wheel is only 2.75")

Mike,

So, just why would you consider moving up a size? You know, CBXs aren't blessed with particularly strong swingarms, and a wider tire will move the cornering forces farther from the centerline of the wheel, increasing the twisting forces and spoiling the aura of that sweet six cylinder music.

Besides, they cost more.

Rick Pope wrote:Mike,

So, just why would you consider moving up a size?

Besides, they cost more.

Main reason is reduced wear and more comfort due to a larger contact patch and my riding two-up on the Prolink 98% of the time.

The price difference I was given by my source is $2.-

Wouldn't putting a tire that needs a 4" wheel onto a 2.75" wide wheel just pinch the sidewalls together and cause the center of the contact patch to bulge out? That would give a larger circumference, but also narrow the tread giving a smaller contact patch on center.



Steve

Same concern here. I am not sure, whether the 4" rim requirement is correct for the 140 tire, seems a little wide to me, but.... I am sticking with the 130/80...