4

I have a Peugeot 107 with 14 inch rims. My tires are bald and require replacing ASAP.

I have a friend who has a Ford Ka with 13" rims. They purchased five new tired (including the spare) less than three months ago and said that It may be possible to swap out my 14" wheels and bald tires for their 13" wheels and new tires.

Is this possible, and what are the implications?

7

If the diameter of the wheel and tyre is different, it will cause your speedometer to show an incorrect reading. Smaller wheels will show a higher speed on your speedometer than your are actually doing. It is riskier to put on larger wheels though as you may be on the speed limit at 30 but your actual speed could be 35.

This is a good site calculate your speedo difference when changing tyres: http://www.tyresizecalculator.com/tyre-wheel-calculators/speedo-error-calculator

You can purchase speedo correctors to adjust the reading your speedometer shows.

You will also need to check that the rims will actually fit. The difference you can find between rims are:

  • The Bolt Pattern - This defines whether or not your wheel hub will line up with the holes on the rims.
    enter image description here
  • The Bolt size - This defines whether the bolts that fit the rim are the correct size for your hub. This generally goes hand in hand with the bolt pattern.
    enter image description here
  • The Offset of the rim - This can play a part in whether or not your rims will fit over the brakes so that there is enough clearance. A rim with negative offset (usually refereed to as deep dish) will have far less leeway for your brakes.
    enter image description here
4
  • 2
    In the offset diagram, which side is the "outside" of the wheel - the left or the right? I'm assuming left is inside, right is outside?
    – JPhi1618
    Feb 12 '16 at 13:41
  • @JPhi1618 Yes you're right, left is the hub side, right is the outside. Feb 12 '16 at 13:45
  • 2
    Great next level answer, James! Feb 12 '16 at 15:20
  • 2
    Don't you mean that "Smaller wheels will show a higher [faster] speed on your speedometer than your are actually doing." ? Feb 12 '16 at 19:05
4

First you have to ensure that the tire physically fits to your car. Beneath the diameter of the rim, there are these characteristics:

  • Number of bolts and diameter of hole circle. The hole circle is the (virtual) circle on which the holes for the bolts are located. This is usually given in the form 4x100 meaning "4 bolts, 100mm diameter"
  • Diameter of the hub / center hole of the rim
  • Rim offset - The offset of the contact surface between car an rim from the center of the wheel (to the outside is positive)

I found this:

                     Peugeot 107  Ka(-2008)  Ka (2009-)
bolts x center hole   4x100        4x108       4x98
center hole            54.1         63.4       58.1
offset                   39           36         35

If these values are correct, rims are interchangeable between none of these cars.

But there is more: The lower limit of rim size is defined e.g. by the brakes. If they are too large, they may not fit inside a 13" rim. I haven't found any 13" rims for the peugeot 107 (but didn't search very much), so may be, they don't fit due to this constraint.

If a rim fits to your car, have a look at the wheel dimension and ensure it has enough clearance.

Finally, a different circumference leads do a different speed reading. Make sure your car isn't faster than it displays, and not too much slower.

1
  • Good point about the brakes. This is probably the single greatest fitment issue with going to smaller rims. Feb 12 '16 at 15:21

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.