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Non standard tyre size, legal (and insurance) issues...

Discussion in 'Businesses and Service Providers' at netrider.net.au started by purdyboy, Jun 19, 2006.

  1. What are the legal and insurance implications of fitting a 180/55 tyre to a Fireblade (or similar 190/50 bike)?
    i.e. not standard fitment.
    Does this leave you open to dramas if you have a costly crash and your insurer voids your cover claiming that your bikes not roadworthy or that the non-standard tyres lead to crash etc etc.

    Does anyone have reliable info (please provide references) on this matter?


    BTW Sorry if this topic has been done before, I did a quick search for existing info on this subject and only came up with this…
  2. Only way to know for sure is ring ur insurance company, it all depends on the wording of there policy.
  3. Thanks for the lightning fast response Woodsy.

    Unfortunately even that is not 100%. When it comes to the crunch they can put the onus back onto you to ensure your bike is roadworthy and therefore insurable on the public road. I went through that with non-standard tyres on a 4WD some time ago (fortunately didn't find out the hard way).

    Hence, i'm looking for any reliable info on bike tyres.

    Bike tyre shops say "no worries" about 180 on 190 bike... BUT, I remember the shop that sold me the tyres for my 4WD said a similar thing, in fact they said I could fit an even bigger size again.
  4. I had to get a written letter saying my bike was road worthy with the exhausts I fitted. I feel better knowing my arse is covered, even though I got a few funny looks asking for it :(
  5. A question (sorry that it's not an answer for you). Why would you want to fit smaller tyres? Remember, the bike's designed to run a specific tyre. When I had 180 section tyres fitted to my bike it handled OK, or so I thought. When I fitted a 170 tyre to it, what the OEM specs are, the bike seemed to handle better.

    You have to consider that too, when looking at changing from a non-standard tyre.
  6. In my experiance insurance companies will refer back to manafactures spec or a 'precident' to try and avoid paying, and in some cases even if it's 'legal' or 'roadworthy' they may still try and get there slimmey asses out of paying.

    Honda do NOT list alternative sizes
    Bridgestone and Michelein do NOT list alternative sizes.

    I'd say for insurance you may be farked
  7. Thanks mjt57.
    I have run a 180 when I used the bike mainly for trackdays. The handling was great but the difference between it and the 190 sizes was not that much. Similar to the difference between the TYPES of 190 tyres I have ridden on. A 180 rear is supposed to make the bike turn-in quicker but there are numerous other ways this result can be achieved.
    My reason for the 180 is: I'm using the bike more to commute now and I have access to a good supply of cheap 180 supersport scrubs. I'd love to use them (and they'd be fine for my application) but not if it voids my insurance.

    I found this:
    So I spose I need to find a good writen reference for a 180 fitment on a 6 inch rim THEN politely wave it all under my insurers nose.
  8. nope, that would make in roadworthy in NSW (and other states with similar legislation) NOT nesiseraly the same criteria an insurance company would use.

    heres the scenario

    ring, ring,,,, ring, ring.

    "Hello welcome to ripemoffandscrewem insurance co"

    'no sorry Mr ripemoff is not in today'. 'oh yu pranged your bike, Mt screwem can assist you, whats your policy number? ok so it's "GETFARKEDWEAINTPAYIN" i'll put you through.

    >insert crapy on hold music<

    'Hello, Mr Screwem speaking, Oh yes hello Mr Purdyboy. yes, yes we'd love to pay out but it's just not possible, yes i know your bike was roadworthy but realy Mr Purdyboy do you realy think a govenment deprtment knows more than Say Honda or Bridgestone or Michelein and they ALL say 190/50/17 tyres for your bike, it's not OUR fault the Government has no idea about these things now is it??'

    'No, No, it's ok we'd be glad to still insure you with your new bike,however we will have to charge you 1000% more now your a bad risk.'

    thank you Mr Purdyboy, ride safe now'
  9. I see you've dealt with my insurers.. you know all their names. :grin:

    What I meant was I get the paperwork to show this is roadworthy and within tyre fitment specs, then wave it under the insurers noses, for a written approval of the mod BEFORE I fit the 180.

    1) It seems RTA refers to, and accepts, the authority of the tyre manufacturers for fitments.

    2) I find tyre manufacture(s) who state, with authority, that 180 and 6" rim are OK (in writing).

    3) I uphold my duty of disclosure and check if my insurer accepts the authority of these... err authorities... with regards to this tyre fitment on my vehicle - in writing. (ie it's legal and deemed safe, but the insurance company is the gate keeper). If they approve they have now accepted to cover a mod from standard which is legal and roadworthy. They can't wriggle out after the fact - can they?

    Maybe this is not correct?

    Oh, stuff it. I'll keep paying for new 190s. :roll: