I still have a tire question!

I've read all the tire info I can find regarding the WRR and still have one unanswered question: How much can one deviate from the rim width specs? It seems that everyone here and on other forums use all manner of tires and of different sizes that require wider wheels than the WRR has. Even for the stock Trail Wing rear tire size, other manufacturers spec a wider rear rim than does Bridgestone. As for the front, there are not that many DOT choices in 80/100-21 so, it seems, everyone uses 90/90-21 instead which, again, calls for a wider wheel. As my WRR sees many more highway miles than dirt miles, I don't want to run into any handling problems. Can anyone offer any info on this?

I'm not all that informed on this, but it seems when I was looking at the same thing that there is normally some latitude in what tires will fit many rim sizes. Just sitting here fuming, playing with my brand new (useless) Heidenau tire, putting your fingers inside the tire on either side and pulling equally outwards, the tire easily flexes outward a quarter inch or so on either side. Take a look at the tire width chart in the stickied post at the top to get some idea of that, i.e. a 120 width rear dirt bike tire is appropriate to 2.15, 2.50 and 2.75 sized rims - the WRR wheel size is 2.15. A 130mm width rear tire is supposedly a 2.50, 2.75, 3.00 proposition - and a 2.15 being too small.

Of course, another chart lifted from another manufacturer might not say the same thing.

Bottom line and rider experience shows that there is some comfortable leeway in either direction as far as wheel size goes.

Bridgestone specs a more narrow rim for the WRR tire sizes than the other manufacturers do. I checked that, at least with the companies that offer those specs. However, it seems that most folks on these forums worry more about trail performance. I can't help but wonder if we might be creating problems on the flip side of the dual-sport coin.

In the past, I remember seeing a chart(s) listing OD, circumference and widths, either in inches or millimeters and revolutions per mile for various off-road tire sizes. Now that I need this info, I can't find it. For instance, how does a 100/100-18 compare to a 120/90-18 or to a 120/80-18? How about a 110/100-18? Or a 4.60-18? I want to stick closely to the stock-size actual dimensions.

Jager, what was the problem with the Heidenau tire?

They shipped me a 19" tire...

If not sticking precisely to wheel size versus manufacturer's recommended size is going to cause problems, there should be lots of stories out there of problems because of doing that. Those kinds of stories seem to be mostly noticeable by their absence.