180 rear on the XR.

[getsome460]

So my track bike has decided not to play ball (Gixxer 750)

I have a day booked next week and a lovely set of TD slicks ready to go on the 750.

I could put them on the XR and go pester the superbike folks but my question is has anyone run a 180 rear? Any issue with rim size or electronics?

I know it's been done on the s1000rr bit the XR is a very different beast.

Cheers Lewis

[Mareng1]

No real experience, but if some have fitted them to the RR for track days - then should be similar rims etc, and in any case - ride within the limits of the tyres (as usual, I suppose?)

[getsome460]

That's where I am at currently, looks like I might be a test mule.

[fozz]

Got a 180 rear on my t595 no problems,( from a 190)and it turns in a lot quicker.

[Winger]

Rim and tyres are matched for a specific reason and i’m More than happy to stick with manufacturers home work, but hey there’s always someone wanting to beat the system...just don’t expect and insurance pay out if you need one in an accident you won’t get it....that’s what they pay assessors for to pull the rug from under the non conformers, and that includes checking if their under the wear limit.

[Antares]

There is reasonable leeway with tyre sizes and rim widths, usually you can go 1 step either way with no issues, but as Winger said, optimal tyre and rim combo was chosen for a reason. If it's out of necessity, I wouldn't sweat over it. Below chart is not complete to XR sizes but you can get the idea from smaller sizes, 120/70 and 130/70 are both standard on 3.5 Inch rims

[Macduff]

Reading some of the tyre test reports on the German XR forum I would expect to see a lot a traction control interference using a different tyre than stock size. They are reporting TC issues with same size tyre from different vendors than what it was homologated with, though think that may be more a Gen1 affliction than Gen2 though I have no experiance on this personally as I've only got 1500miles on my stock tyred Gen2.

[Antares]

Originally Posted by Macduff

Reading some of the tyre test reports on the German XR forum I would expect to see a lot a traction control interference using a different tyre than stock size. They are reporting TC issues with same size tyre from different vendors than what it was homologated with, though think that may be more a Gen1 affliction than Gen2 though I have no experiance on this personally as I've only got 1500miles on my stock tyred Gen2.

I can't imagine that being a problem. Tyres have widely varying circumferences even in the same sizing. Pirelli Diablo Rossos are very tall, Metzelers are much flatter. And then add wear into the mix, The road 5 comes with tonnes of thread and can wear down to much lower circumference and it barely causes issues. As long as the aspect ratio is accounted for a 180 shouldn't be much smaller than a 190 to begin with. If BMW made a system that heavily relies on the circumference they're both crazy and stupid, but since the TC always works and it works amazingly, I just don't think that's the case.

[marksmcparts]

Fit the 180 & gently approach the limit so that if something wierd happens it doesn't take you too much by surprise.

Odds on it'll be fine.

[Winger]

Be interesting to find out if an insurer would pay out on a claim, because a 180 most certainly isn’t in spec, from a practical point of view certainly going to be an interesting learning curve, never been hard up enough to have to try such, most posts are 50/55 profile.