Rimming

[austinpowers]

My 11S has the five inch rim. Looking at it next to another machine with a five inch, the S appeared to be wider all round. Out came the Verniers, and measured across at the narrowest gap (to match where the tyre rim is seated) I came up with a digital read out of 5.55 inches, seemingly contradicting the claim stamped on the hoop itself....

But this is by no means unique. The bike next to it, my ZRX, also allegedly had a 5 inch rim but in fact measures 5.33 inches and takes a 180 section (Metzeler) pretty comfortably if required. Different 180s (or any other section) may vary considerably from make to make.

So before anyone rushes off to find the 5.5 inch rim (to accomodate 180s) measure up first. You never know. If you're closer to 5.5 than 5.0 you're in the ballpark.

[McBoxer]

Interesting. I'm pretty sure the rim width measurement should be taken between the inner seating faces - ie, where the bead sits inside the wheel - so I would expect the outside of the wheel to measure wider. How much wider will depend on the design / material of the wheel of course.

Does this picture match the measurement you took?

[SP250]

The 5" 1100S rim will accept a 180 section tyre but it pulls the beads inwards and therefore the profile is out of shape.
It reduces the width of the contact patch and makes the shoulders curve inwards also reducing the patch when leant over.

I have run both 180 and the correct 170 section tyres on the 5" rim and the difference was quite marked.
Bike was much nicer on the 170 and less "nervous" at the rear but also steering more positively. Tyres are cheaper too.

Can't say what it does on the 5.5" rim and 180 tyre.

[austinpowers]

Interesting. I'm pretty sure the rim width measurement should be taken between the inner seating faces - ie, where the bead sits inside the wheel - so I would expect the outside of the wheel to measure wider. How much wider will depend on the design / material of the wheel of course.

Does this picture match the measurement you took?

Measured up externally making allowances for where the bead sits inside the rim. If anything, I was on the conservative side...

In reply to SP, this means it is effectively a 5.5 rim so there should be no distortion with a 180 in situ. Also worth remembering not all tyre manufacturers 180 sections (for example) are the same. A Metzeler 180 may not be the same as a Dunlop for example. All I'm saying is, it may be worth people who want a 180 section on their bike to measure their 5 inch hoop first....

[adam]

The 5" 1100S rim will accept a 180 section tyre but it pulls the beads inwards and therefore the profile is out of shape.
It reduces the width of the contact patch and makes the shoulders curve inwards also reducing the patch when leant over.

I have run both 180 and the correct 170 section tyres on the 5" rim and the difference was quite marked.
Bike was much nicer on the 170 and less "nervous" at the rear but also steering more positively. Tyres are cheaper too.

Can't say what it does on the 5.5" rim and 180 tyre.

A lot of people make this mistake on Buells too. The handling on a 170 section tyre is much more precise when fitted to the rim.