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PreludeTAS
1st November 2006, 09:35 PM
Ok so this may sound like a bit of a noob question, but I've gotta ask it, so contain your laughter.

Consider a 17 inch rim. Can multiple tyre sizes fit on the rim, or just 1 particular?

For instance, could a 215/45 tyre fit on the same wheels that currently have a 205/40 tyre?

Menthu Rae
1st November 2006, 09:40 PM
Yes you can fit multiple sizes, but certain rims suit certain sizes best...

e.g. 6.5" wide... 205 tyre... 7" wide... 215 tyre... 7.5" wide... 225 tyre... etc

It also depends on sidewall height, because that determines how much "stretch" you can have. Basic rule of thumb is times the rim width (in mm) by about 12 to get the tyre width required.

If you're going for wider tyres, you want lower sidewall height... e.g. 205/50R16, you'd want something like 215/45R16 or even 215/50R16. Use this site to help you out...

http://www.miata.net/garage/tirecalc.html

ENDLESS
1st November 2006, 09:45 PM
u have to ask the guys at the tyre place cos we dont know what tyres u want yet, and like Jesus said above, diff tyres have diff tyre wall structures and etc

it will stretch to fit definitely, but it will compromise the strength and design of the tyre wall and tyre itself

Menthu Rae
1st November 2006, 09:50 PM
u have to ask the guys at the tyre place cos we dont know what tyres u want yet, and like Jesus said above, diff tyres have diff tyre wall structures and etc

it will stretch to fit definitely, but it will compromise the strength and design of the tyre wall and tyre itself

Yeah one thing I neglected to mention, because I should be doing transformation of stresses right now, is that if you go for a wider tyre with thinner sidewall - you will change the characteristics of how the sidewall flexes.

This will impact handling, comfort, road noise, etc.

Basically stick with the rule I said above, multiplying by 12, and using the correct sidewall height to maintain overall rolling diameter within 1-1.5% or so and you'll have the best of all 3 worlds, handling, comfort, road noise (and safety). :side:

PreludeTAS
1st November 2006, 09:54 PM
Yeah ok, bottom line is, I spent farking ages trying to find some rims I like. I found some, thought I'd take all the precautions and make sure it fits etc... however I only took into consideration the stud pattern (which is 4 x 114.3 and fits nicely).

However the tyres on these particular rims are 205/40, and I went to Bridgestone today to get them fitted to my car, and he looked at my car (didnt even see the wheels) and said I think you're gonna need 215/45. Something to do with the rolling distance or something I think he was going on about...

Anyways, so I was wondering if I'm gonna have to scrap the wheels or if I can get them fitted with 215/45 tyres. If its going to compromise the wall structure of the tyre, then I don't want to do that.

I just measured the 205/40 tyre on the wheel, and its 7.5 inch across

Menthu Rae
1st November 2006, 09:57 PM
You can't measure the tyre, you need to find out the rim width.

Give us the rim width, and the measurements of your stock rims/tyre setup and we can tell you what to go for.

Need:

Old - Tyre Size (e.g. 205/50R16)
Old - Rim Size (e.g. 16")
Old - Rim Width (e.g. 6.5")

New - Tyre Size (e.g. 215/45R17)
New - Rim Size (e.g. 17")
New - Rim Width (e.g. 7")

PreludeTAS
1st November 2006, 10:01 PM
Ok I can't measure the rim width as I'm not prying the tyre off it.

My current set up is:
195/60 R15

I would like (so that I don't have to buy new wheels)
205/40 R17

But if compromising tyre structure becomes an issue, i'll sell these rims and buy some ones that bloody fit properly.

Menthu Rae
1st November 2006, 10:07 PM
Well what brand and model are your rims? You don't need to measure it - just find out!

Anyway so long as the width is fine for the tyre width... the overall rolling diameter is wayyyy too small, it's off by 3.1% - means if you're doing 100km/hr on your speedo... you will actually be doing 97km/hr

You really want to go for 205/45R17 if you want to keep it within stock levels, only 0.2% variance...

PreludeTAS
1st November 2006, 10:09 PM
Cheers dude, I'll keep that in mind.

Unfortunately I have no idea what the rims are, there's no writing at all on them, and I bought them 2nd hand. They look old.

Menthu Rae
1st November 2006, 10:25 PM
Cheers dude, I'll keep that in mind.

Unfortunately I have no idea what the rims are, there's no writing at all on them, and I bought them 2nd hand. They look old.

Try measuring inside the rim then... from inside lip to outside lip. If that makes sense...

PreludeTAS
1st November 2006, 10:30 PM
Ok measured the inside lip to outside lip...
does 8.5 inches sound about right? (hehe, not talking to you ladies, *boom tish!*)
Seems larger than the tread surface of the tyre when I measured that... hmmm

Menthu Rae
1st November 2006, 10:58 PM
Ok measured the inside lip to outside lip...
does 8.5 inches sound about right? (hehe, not talking to you ladies, *boom tish!*)
Seems larger than the tread surface of the tyre when I measured that... hmmm

Hrmmm if they were 8.5" I doubt they'd even fit on your car dude... also no way would 205 tyres fit...

Find out for sure (somehow) what the rim width is, and we can tell you what to go for :side:

Bob
1st November 2006, 11:26 PM
Rim dimensions are usually stamped into the rim.
Take a look at the inside of the hub. Are there any markings.
Chances are you will see 17x7 somewhere.

PreludeTAS
2nd November 2006, 12:27 PM
I will have to look at the rim dimensions when I get home.

But i've done some research and found the following:

http://www.maxauto.co.za/cntview.asp?CatID=37&CntID=423

This site states that the recommended wheel and tyre combination for a 92-97 Prelude is the following:
4 x 114.3
Offset: 50
Sensible: 7J x 17"
Tyre: 205/40

Does that sound about right? Should I be asking my tyre dealer to hook me up with that setup?