Smaller Tire for clearence

[hogboy]

Does anyone have a 130/80 or 90/16 mounted on a 3" rim? I'm trying to find some mounted demensions of one on the rear. I have a 150/80B16 mounted on a rigid sporty and it rubs the fender sometimes when riding. I made a mistake during mockup and didn't catch it till the bike was painted, so I'm looking to downsize the tire. All help would be appreciated, thanks   HOGBOY

[PC_Hater]

It will depend on the tyre you are using. The Avons, Dunlops, Metzelers are all slightly different widths for a nominal 130/90 16" tyre. The manufacturers websites will give you exact figures.

The info I have at this instant is for Conti tyres. They quote tyre sizes when new and then the max service limit at 240kmh = 150mph.
Cold their 150/80 16 tyre width is 150mm (5.9"), at 150mph it can become 165mm (6.5"). (Perhaps you should ride a bit slower then?)
Cold their 130/90 16 tyre width is 129mm (4.85"), at 150mph it can become 142mm (5.6").

The diameter of the tyre increases with speed too. At 150 mph on the 150/80 it changes from 646mm (25.4") when stationary to 662mm (26"). The 130/90 changes from 640mm (25.2") to 656mm (25.8")

Unless your fender really is dangerously close to the tyre - as in less than half an inch clearance on the diameter and about 0.25" at the sidewalls  - I would suggest you check to make sure the fender isn't rattling about over the bumps. Metzeler pride themselves on making tyres that grow the least with speed which is why the pro chop builders use them to get the fender very close to the tyre.

I would keep the 150/80 tyre and 'adjust' the fender as necessary!

[hogboy]

The 150/80 I have is a Dunlop and It is dangerously close and I have already been told I told you so by all my buddies. It rubs at slow sppeds, Moving the fender sounds easy but there are lots of tight issues, siisy bar bracket my electrics and just mainly how I mocked it up. It rubs in the middle and on the sides. I really screwed up.

[PC_Hater]

Oh. Riding your chop at 150mph would have been funnier!

Again, using Conti figures.
The 130/90 will give another 0.1" of clearance in the middle when compared to the 150/80.
The 0.2" difference is the diameter - in this case we must use the radius so it halves...
Is 0.1" enough?
The reduction from 5.9" to 4.85" in the width must at least solve the rubbing on the sides of the fender.

Someone you know has a worn 130/90 16 tyre you can fit and see if it works.
If it still rubs, don't forget that Jap cruisers often use 130/90 x 15" tyres. Needs a new rim, but that may turn out to be your best escape route.

http://www.dunlopmotorcycle.com/ lists the tire sizes for HDs. The difference in diameter on the D401 150/80 and 130/90 is only 0.050"!
You need to have a look there now!
And I'm off to bed. It's late here!

[hogboy]

ya 150mph would be a better BS story iwish it was that way. Thanks for your input, it looks like I am going to have to do alittle of both smaller tire and SOME FENDER WORK which will be a pain. That 150 looks great on there.