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Few Qs I need answered...

Posted:
Wed Feb 03, 2010 9:22 am
by Laps
Hello all,
In the coming month I will be ordering rims (
http://www.tech9tyres.com.au/index.php/wheels/listing/C45/).
These come in 19x8.5 5x100 and weigh 25.0 pounds
First Question:
These come with tyres, but im not sure what size to get? Basically I want to get a smooth a ride as possible. What are the pros cons for each size? Brand/Model supplied in the package is Achilles ATR Sports, they come in:
225/35/19 88w (valued at $240 each)
235/35/19 91w (valued at $240 each)
245/35/19 93w (valued at $240 each)
275/30/19 92w (valued at $300 each)
Second Question:
I am getting Pedders Extreme XA Coilovers installed. I am wondering if you think I will need to have my guards rolled (I plan on have my rear fender almost equal with the top of the tyre, similar with the front)? If so, will I need to get the rolled prior to getting the springs/rims, or is it ok if I do it a few weeks later (I get paid Monthly). I called a place in Canberra called J Racing, who are meant to have a pretty good reputation with this sort of thing. They quoted me $60 a corner, and said there is a chance my paint could crack... I dunno if im happy about that (paint cracking, not price). Does every company just say this to cover there asses, or is does it happen alot? Any suggestions here?
Third (Final) Question:
Which colour rims should I get lol? Black or Titanium Charcoal... Im leaning towards the Titanium Charcoal which is assume is a dark gun metal colour (see above link for images)

Thanks for your time

Re: Few Qs I need answered...

Posted:
Wed Feb 03, 2010 10:31 am
by 04GTLIB
Alex.
Firstly being a +45 offset, i personally wouldn't go any wider than a 225 tyre.
So you could go with a 225/35/19 or you could try a 225/40/19. The 40 series option may give better ride quality.
Secondly, getting the guards rolled would be a good idea.
I run a 8.5" wide rim with a +45 offset and I needed to roll mine to stop slight front and rear rubbing.
Lastly, colour is up to you.
But if it was me I personally would go with the charcoal colour.
Just my opinion on your questions, hope its helpfull to you.
Cheers,
Rusty.
Re: Few Qs I need answered...

Posted:
Wed Feb 03, 2010 10:58 am
by Laps
Ah ok thanks for that, all very helpful.
About tyre size, I dont think they are offering a 40 series option (what does the series part even mea)?. Whats the difference between 225, 235 and 245? Is it how far from the top of rim to top of tyre (the tyre wall), or how wide the actual is (if you look at a car from behind/in front). If its the size of the tyre wall, wouldnt a smaller wall mean a more bumpy ride??? Also, forgot to ask this before, but whats the go with changing my wheel diameter. What dimensions will keep my diameter the same so I don't have to have my odometer adjusted?
About guard rolling, yeh I thought I may have to do this... Hope my paint doenst crack!...
About colour, yeh charcoal is the go i reckon...
Re: Few Qs I need answered...

Posted:
Wed Feb 03, 2010 11:38 am
by smythie
Ok, your tyre size code broken down
eg 225/40R18
The 225 is the nominal cross sectional width of the tyre (across the tyre).
The /40 refers to the sidewall height of the tyre. It means the sidewall height is 40% (in this example) of the width of the tyre
The "R" means that the tyre is a "radial" type rather than cross-ply or bias-ply or other types. (don't worry too much about this as just about every modern car tyre is a radial type.
The 18 at the end refers to the rim diameter (usually in inches)
When people refer to "40 series" or "50 series" regarding tyres sizes they are referring to the sidewall height part of the tyre size code.
Re: Few Qs I need answered...

Posted:
Wed Feb 03, 2010 12:45 pm
by Laps
Ahhh ok...
So I think I would want a 30 series as aposed to a 20 series for better comfort?
Will putting a 35 tyre on a 19 inch wheel increase the liberties stock diameter?
What are the major pros/cons of a 20 series tyre vs a 30 series tyre...? Surely smaller wall = less comfort, so I am finding it hard to understand why anyone would choose a 20 series tyre for anything other than looks?
Re: Few Qs I need answered...

Posted:
Wed Feb 03, 2010 1:46 pm
by smythie
you've got it - looks. Even serious racers won't go much below a 50 series profile and they are usually running around on (relatively) smooth tarmac.
To answer your question about rolling diameter, going from 215/45R17 (I *think* that's your stock size) you are going to be well out unless you get something like 225/30R19 which for mine is going to be ridiculously harsh. YMMV. 215/35R19 will be slightly bigger than the 225/30 option. I'd suggest to get a tyre that fits your wheels and clears the guards and then get your speedo recalibrated
Re: Few Qs I need answered...

Posted:
Wed Feb 03, 2010 1:57 pm
by Laps
Ah ok, so I wouldnt be able to fit a 35 on it? As in, isnt it illegal to change my rolling diameter?
So out of the 4 tyres I listed, to 30 would be the best as it is the smallest and widest? (as in 35 would be too big)?
So confused ;[
Also, who would i visit to have my speedo recalibrated? Or do tyre shops do this?
Last of all, here are my results with a tyre calculator (tyres listed above vs stock tyre - 205/50/17
225/35/19 88w - Speedometer: 0.521% too slow - Diameter Difference: 0.52%
235/35/19 91w - Speedometer: 1.591% too slow - Diameter Difference: 1.58%
245/35/19 93w - Speedometer: 2.711% too slow - Diameter Difference: 2.65%
275/30/19 92w - Speedometer: 1.666% too slow - Diameter Difference: 1.65%
Now, its little confusing how the first 3 tyres have the same size wall, yet differen diameter difference????
As with the speedometer being slow, i asume thats something that can just be fixed with recalibration?
Sorry for this btw ;[ lol
Re: Few Qs I need answered...

Posted:
Wed Feb 03, 2010 2:13 pm
by smythie
I don't know that it is illegal to change your rolling diameter. I reckon it would be a good idea for you to check with your insurance company about whether you will be covered after you change your wheel and tyre size to something other than on your car's tyre placard. Make sure you get any assurance in writing (or have it in writing in an up to date PDS for your policy).
If your insurance company is fine with it get a tyre that fits on the rim (225 is probably about as skinny as you could reasonably go on an 8.5" wide wheel) and clears your guards. You'll probably end up with 225/35 going by other guys' experiences though you probably could go wider with rolled guards.
Once you have your new wheels and tyres on it, get the speedo recalibrated. Tyre shops generally don't but you should be able to find someone in the Yellow Pages who can do it for you.
Re: Few Qs I need answered...

Posted:
Wed Feb 03, 2010 2:34 pm
by Laps
Im insured with AAMI and they said they dont care what mods I do as long as my car is street legal.
I dont understand how you can have more than one width of tyre on a 8.5 inch wide wheel. 8.5 inches = 215.9 millimeters. So how can you have all these different widths, such as 225, 235, 245, 275?
Re: Few Qs I need answered...

Posted:
Wed Feb 03, 2010 2:52 pm
by teK--
Every tyre width has a range of wheel widths on which it can be safely fitted. Check the sidewalls of various cars they are not always perfectly perpendicular to the wheel width.
AAMI are OK with most basic mods but not all. Best to check the actual mod you want before you install it because it's too late if you ring up to add a certain mod and they refuse you cover. I left AAMI for that reason because they didn't like some of the mods I was making.
Re: Few Qs I need answered...

Posted:
Wed Feb 03, 2010 3:04 pm
by tangcla
Laps wrote:225/35/19 88w - Speedometer: 0.521% too slow - Diameter Difference: 0.52%
235/35/19 91w - Speedometer: 1.591% too slow - Diameter Difference: 1.58%
245/35/19 93w - Speedometer: 2.711% too slow - Diameter Difference: 2.65%
275/30/19 92w - Speedometer: 1.666% too slow - Diameter Difference: 1.65%
Now, its little confusing how the first 3 tyres have the same size wall, yet differen diameter difference????
It's because that's 35% of 235mm, 245mm and 275mm.
Re: Few Qs I need answered...

Posted:
Wed Feb 03, 2010 3:06 pm
by tangcla
Laps wrote:I dont understand how you can have more than one width of tyre on a 8.5 inch wide wheel. 8.5 inches = 215.9 millimeters. So how can you have all these different widths, such as 225, 235, 245, 275?
It's called stretching your tyres. Looks more drift spec.

Re: Few Qs I need answered...

Posted:
Wed Feb 03, 2010 3:36 pm
by Laps
ok ok, i think im beginning to understand...
tek, what mods were you making that AAMI didnt like?
Also ppl, out of the 4 sizes that i pointed out coming in the package, which do you think is best for my needs?
Re: Few Qs I need answered...

Posted:
Wed Feb 03, 2010 4:25 pm
by jdm rsk
Now I am confused

Re: Few Qs I need answered...

Posted:
Wed Feb 03, 2010 6:12 pm
by coyote
Laps wrote:235/35/19 91w (valued at $240 each)
I suspect that is your only choice.
245 won't fit and if you check your tyre placard, it just might say 89.
Shit tyre though.