Yup, him again

[puskrat]

Hi gang. I looked around under tires, and learned things, but not what I'm seeking. I like the fat tire look. I remember seeing a YouTube video where some self-styled wishful builder repeatedly described his build as "athletic", "agressive", or something similar because of his amazing styling choices.

I think my attraction for big tires is similarly silly, but I'm leaning anyway.
What are the actual physical dimensions of the standard (or superceding modern) sizes, OD and width of the tire/rim assembly? I know bigger rubber means wider openings for it to move through, but I dunno how much.

Second part....I've been talking with a local builder about Wheel sizes as we mock the Big Wheel bikes filling bagger magazines and TV. How much impact does pure tire weight affect steering physics, without substantially upsizing the diameter of the gyro?

Guess I'm talking about using a wider tire of the same nominal diameter. Is that even possible? Will it fit the rim? I thin kI'm asking my questions out of order, but what do I know. I'm only a paper pusher

[jwhughes3]

Your issue wont be the rim. These bikes are shaft drive. There is only room for a 140 to fit and then only some brands.

You need to perhaps do a chain conversion to make the swingarm the limiting factor.

John

[puskrat]

Looks like big bold rubber is not a design choice for this machine. That's fine. No need to change stuff that works.

[TopCatGr58]

Hey there,

There IS a little more room available on the swingarm/driveshaft area. Yamaha built a recess for the stock 130/90/16 tire for a Special. Depending on brands, folks have been able to put a 140 on there, but plain sidewall....the raised white letter type often rubbed. A few folks, and I myself will be doing this in the winter....cutting out the recess, mounting the driveshaft and final drive back in place to figure out how CLOSE I can put the patch back onto the swingarm/driveshaft housing to just miss the spinning driveshaft and still allow a little more room for a slightly wider tire.

I currently have a 140/90/16 Dunlop Elite III on there, and have even put some 2mm thick washers between the wheel hub assembly and the rim to further space the rim a little farther away from the swingarm. But under some maneuvers there's still evidence of the sidewall flexing enough to very slightly rub against the swingarm recess.

I'm hoping for enough room for a 150 rear, but if not, at least to gain enough room for my 140 so that it will no longer rub the swingarm. YMMV!

T.C.

[jetmechmarty]

Looks like big bold rubber is not a design choice for this machine. That's fine. No need to change stuff that works.

You got that right. It would be an awful expense and all to the detriment of handling. There is no advantage to the fat tire other than aesthetic. 130 was a fat tire when this bike was new.

[Bikes]

As far as handling, a little goes a long way....when I was riding sport bikes, zx12 and such, I would go down one size and it made a world of difference...on my xs, I went up one size because I'm looking for more tire on the pavement when touring, wet, loaded etc....not really concerned about the loss of "crisp"ness....
I rode a big tire chopper once and it was pretty bad...looked good though...

[James England]

As far as handling, a little goes a long way....when I was riding sport bikes, zx12 and such, I would go down one size and it made a world of difference...on my xs, I went up one size because I'm looking for more tire on the pavement when touring, wet, loaded etc....not really concerned about the loss of "crisp"ness....
I rode a big tire chopper once and it was pretty bad...looked good though...

IMO, sacrificing handling for looks for handling isn't a good idea. It depends on how you intend to use the bike, of course. If it's for looks mainly, then it might be worthwhile but anything else would bother me. As has been said, the clearance to the shaft is tight at the best of times....

[puskrat]

Dont want to drag this topic out, as my question has been answered, but while others have an interest in the conversation, I'll go along. For me it's no longer a question. Tire size for me...I wanted to go Street Tracker style I guess. Wide "oxymoronic custom chopper" style looks are of no interest to me. One tire size might have mad that difference, but I might get more return for less trade off with a dirt or dual sport tire, if the ODs will work. OH yeah did I mention I'm looking to go lower?