yoashman said:

Hey,

Im wanting to get some new tyres for my Landy 90, the current tyres are 245 70 15, but I am finding it hard to find any tyres on the internet of that size (Im looking for mud tyres), can any of you suggest a tyre of that size, or is it possible to change the size of the tyre without affecting the landys handling/safety, say to 245 70 16 for example? Any help you can throw my way would be grand, cheers.

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yoashman said:

Hey,

Im wanting to get some new tyres for my Landy 90, the current tyres are 245 70 15, but I am finding it hard to find any tyres on the internet of that size (Im looking for mud tyres), can any of you suggest a tyre of that size, or is it possible to change the size of the tyre without affecting the landys handling/safety, say to 245 70 16 for example? Any help you can throw my way would be grand, cheers.

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yoashman said:

Hey, yeah done a search, and realise I cant alter the rim size, but cheers.

Guess I didn't make myself too clear, the numbers 245 70 15, is it possible to adjust the first two numbers (245 70), with out to much of a bother on the landy? Do I only really have to worry about the rime size? Just looking for a bit of advise or a possible "check these out" is all. Cheers.

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Mike_B said:

I'll help you out, because i'm in a good mood!

245 is the width of the tyre's tread, in mm. 70 is the height of the sidewall, expressed as a percentage of the tyre's width ( ie, the tyre wall is not 70mm tall, it is 70% of 245, tall. In this case 171mm) 15 is the wheel diameter ( which is the same as the tyres internal diameter! - for this reason, you cant switch from a 15 to a 16, without buying 16" wheels)

If you were to chance, lets say, from a 245/70/15 to a 265/70/15, as well as increasing the width of the tyre, you have increase the height of it too, as 70% of 265 is 185.5mm. This affects the gearing of the car, as it was originally designed to run on a tyre with a set rolling circumference ( the amount of distance travelled per circular rotation). This will also affect your speedometer accuracy, as the speedo makes its reading based on a known tyre circumference, which you're about to change.


Then you have to take into account whether or not the wheels will physically fit onto the car, without fouling any of the suspension components, whether you can actually turn the wheels without rubbing things like wheel arches / liners. Finally, will the tyres stick out past the wheel arches? if so, you need new arches, or thinner tyres as it's illegal.

look on a website like this one, enter your current sizes and the sizes tou want to change to, it'll tell you whether or not you can do it.

Sounds really complicated, its not too bad. Do a search at the top of the page, it'll give you all the help you need.

TYRESAVE: Tyre Size Calculator

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