Offroad-Express

right, i got my two new tyres today, requested 33x12.5x15 inch tyres.

had them fitted up, stood back and sorta thought, damn they look small...
but it said 33x12.5 on the sidewall.

got it home and measured them up, and they come in just under 32inch diameter, and 9 inchs of tread width...

the 1/4 worn hankooks im running on the front are about 32 1/4inch diameter, and have 10 inches of tread width...
also says 33x12.5

now isnt that misrepresentation of the tyre? ive clearly asked for and paid for a 33x12.5 inch tyre, yet in reality ive got one that is barely bigger than a 31inch tyre...

by the time the new tyres are half worn they will be less than a 31inch tyre...

now i know you get what you pay for, and they were cheap... buuut, surely if its represented as a 33inch tyre, then it should be a 33inch tyre shouldnt it?

Damn straight My non ginga brother of another mother!!!!!
Take them to task over the fact!!!!
Stick it to the man!!!

Id sure be pissed if I had bought brand new 33x12.5s and they were 31x9s, Thats pretty shitty really man.
You should just take them back and buy some real ones.

what psi do you have in them? obviously if your running 30 and they advise running 60 they will be smaller but that width does sound small...

Nailz wrote:Damn straight My non ginga brother of another mother!!!!!

dude, you crack me up sometimes....

rangimotors wrote:what psi do you have in them? obviously if your running 30 and they advise running 60 they will be smaller but that width does sound small...

they pumped them, i have no idea what psi they are...


gooing back out there this arvo, fully not impressed...

Dead right..you pay for 33 you should get 33....youve been short changed. I bet they would of moaned if they said the price was $200 but you only gave them $175.
Get them to sort it out.

been back, basically he said all the cheaper tyre brands do it, theres a thing in the stock book that says allow up to + or - 5% variation in size... and it coincidentally (yeah right) its damn near spot on 5% under sized...

if i want an actual 33 inch tyre in a cheaper brand then i pretty much have to go to a 35inch tyre...

the narrower tread width is (he says) because its a mud tyre rather than an atr like i have on the front.and that the width shouldnt be measured from the edge of the tread, but rather from the widest part of the shoulder/sidewall, which came in at near as damn it to 11.5inchs, also pretty bloody close to that 5%...

bonus is though, we measured both types that i have on, and with the pressure equal and on flat ground there is only 2 or 3mm off difference.
its the different styles of tyre that makes it look like theres a difference in height.

be interesting for some of you guys to go measure your tyres and see how they come up...

could make a list of the brands that actually give you close to what you are paying for...

to me it seems like blatant false advertising/mis-representation by the tyre makers... but i dont really see what can be done, other than work out which tyres are more accurately sized and support those brands.

5% My ass!!!

So what'd you do? Tear him a new arsehole and ask for a refund or exchange to a set that actually is 33x12.5?

So you are running 2 different brands?

Nailz wrote:5% My ass!!!

So what'd you do? Tear him a new arsehole and ask for a refund or exchange to a set that actually is 33x12.5?

sweet fa i can do, its not the retailers fault that the manufacturer is bullshitting on it, i needed the tyres anyway, theyre pretty much spot on diamter wise with my front tyres.

short of a civil suit against the tyre maker or complain to the commerce commission (hmm, thats an idea) dont really see what i can do.

the only way he could guarentee me getting the 33 inch tyre was getting simex's or similar, cos apperantly with the good high quality tyres you do get what you wanted.

but damned if i can afford $4-500 a tyre...

oh, and i measured my 31's of my donor surf, and the two 'savero's' measured 29 1/2 ish inchs, and the firehawks spot on 30inchs....

DaveM wrote:So you are running 2 different brands?

yeah, im running Hankooks on the front and mudmax or mudshot or something on the rear, cant remember lol

nstg8a wrote:the only way he could guarentee me getting the 33 inch tyre was getting simex's or similar, cos apperantly with the good high quality tyres you do get what you wanted.

33/12.50/15 Hankook RT01 Mud tyre is ony approx 32 inches tall

my 33 inch groundhawgs measured 33 when new, and the Creepys are pretty close to 35.

i think i might end up running two sets of rims... one for road use and one for off road use...

buggered if id be willing to tear up a good set of mud tyres on the tarseal...

nstg8a wrote:
the only way he could guarentee me getting the 33 inch tyre was getting simex's or similar, cos apperantly with the good high quality tyres you do get what you wanted.

but damned if i can afford $4-500 a tyre...

Simexs are the other way. a 32" measures 33" and 35" measures 36"

welcome to the wonderful world of tyres

having been in this industry for a while, you can take it from me that no two makes of tyre will be the same.

even car tyres are wrong

I have sold a 215/35x18 that when placed next to a 245/40x18 is actually wider, and can cause problems when fitting to a car that only just fit them before in another brand and the new brand rubs everywhere.


I have found that most 4wd tyre sizes are in fact out by at least an inch, except for BFGs and those that make a bias ply aggressive tyre like the maxxis, ground hawg, simex and swamper range of tyres.

as you have found out it is something that no retailer will want to take the blame for.

most manufacturers now are supplying actual sizes in thier price books, so ask your retailer first to find out what the actual dimensions of the tyre are.

to those of you that have found out the hard way, theres not much I can say

skid wrote:most manufacturers now are supplying actual sizes in thier price books, so ask your retailer first to find out what the actual dimensions of the tyre are.

yup, i found that when we were gong through the catalogues, will certainly know better next time...

the cheapest 35 he could get me was a kumho, for about 330 each fitted, and according to the book the actual dimensions were 33 3/4 inch...

This is one area you need to do some serious home work.
Take Simex as an example. 35x10.5 is actually 34.6 but a 35x11.5 is 35.5!
Most good brands will now tell you actual size but then you have to take into account wheel width as this affects hieght as well. Most 12.5 wide tyres are supposed to be on a 10" wide wheel. Stick it on an 8" then it will be quite a bit narrower!

darinz wrote:Stick it on an 8" then it will be quite a bit narrower!

but it will be taller and if you stick it on a 10" rim it will be lower.

it will always be a sticky topic, but at least everyone will know about it and hopefully be able to make thier decision based on what they get told and what info they can get from here.

This may help.

The tyre will measure a different diameter if it is on the vehicle because of the weight.

e.g. if the tyre is 30" tall,top of the tyre to centre off hub is 15"but centre of hub to ground could be 13.5". Many things can effect it as someone else said rim width,tyre pressure,weight of vehicle etc

Have a look at this web site it may explain better than I can

http://www.vibratesoftware.com/html_hel ... Radius.htm

4xxx4 wrote:This may help.

The tyre will measure a different diameter if it is on the vehicle because of the weight.

e.g. if the tyre is 30" tall,top of the tyre to centre off hub is 15"but centre of hub to ground could be 13.5". Many things can effect it as someone else said rim width,tyre pressure,weight of vehicle etc

i always measure horizontally..... not vertically. otherwise tyre pressure would have a huge effect.

BFG is the only radial MT tyre that I know off that measures it rated size,but you do pay more for them.

Even Though I have never owed them (simex)there actaul tyre size specs seam inaccurate when compaired with the actual tyres them self.They are genrally larger than there rated size.

I well own a set one day

Shane

Best thing I ever did was develop a relationship with a good tyre outlet. One of the guys there is really keen on 4WD and is always happy to help out with advice and info. I don't want to incur the wrath of the moderators, so I won't give details of the business, but good staff at a reputable company can be great to deal with because they know tyres wear out, and you'll be back. Again and again, and again........

Equally, I make sure that those people who look after me get my absolute loyalty, and referrals wherever possible.

ive got a set of super swamper tsl 33x12.5 15 , they are nearly bald and still measure just over 34 inches
as for a cheap tire most of the 33": savero 's ive seen measure up pretty good

One of the guys at my work just got some new 265s. we put the ruler across the footprint and got 200mm.....

Nailz wrote:One of the guys at my work just got some new 265s. we put the ruler across the footprint and got 200mm.....

width isnt just measured on tread width though dude, shoulder to shoulder...

this whole topic has definitly got me asking questions when pricing up tyres, and i still think its bordering on being downright mis-leading...

i fired off an email to the commerce commission on friday querying the whole thing, so we will see what they say.

good call. bringing in the commerce commission will make the tire companies sit up and take notice
when a stated tire size ends up being smaller (or bigger) than another common or made size something is a miss
eg. if it measures up at 32" why call it a 33"