Thread: Tyre sizes still a bit confused

Beadlocks are used to secure a tyre to rim. They are not really required at pressures of more than 15psi provided you are not driving like bat out of hell, and you can go as low as say 8 if you're nice and gentle.

Very large tyres such as those fitted on comp cars must be deflated a long way to air down, often below 15. Funnily enough, these cars tend to be driven with a bit of brisk pace. Hence the popularity of beadlocks.

Even if you do pop a tyre off a rim it's not a big problem to pop it back on again.

I ran internal beadlocks for over a year in my D1 - both in comps and as a daily drive. Never had issues with balancing or handling. You never notice that they're there.

However, they are a significant investment (around $250 each), you have to drill a hole in the rim for the additional valve, and they're only really useful at pressures under 14psi, so unless you do that on a regular basis (and drive like you stole it), it's probably not a "must have" accessory.

Cheers,

Gordon

Originally Posted by rmp

DJ
Australia is over-governed in some ways..

Some ways ! How about "in all respects".

On tyres:

This might be useful to people:

Tire size calculator

Just an update to this subject discussed recently.. Found this on the Vicroads website after talking to local Tyrepower man re legally allowed sizes. He said it was 2" or 50mm and it had been changed recently. Here's what it says on Vicroads website:
"OVERALL DIAMETER
Section LS Tyres, Rims, Suspension & Steering
The overall diameter of any tyre fitted to a passenger car or passenger car derivative must not be more than 15mm larger or 26mm smaller than that of any tyre designated by the vehicle manufacturer for that model.
The overall diameter of any tyre fitted to an off-road passenger vehicle or a commercial vehicle must not be more than 50mm larger or 26mm smaller than that of any tyre designated by the vehicle manufacturer for that model.
Speedometer accuracy must be maintained for the selected tyre and rim combination to within the degree of accuracy specified in ADR 18 where applicable."
So it appears that BFG KM2MTs 265/70/17 (804mm diam)or 245/75/17 (800mm diam) are legal now.
Any body fitted these sizes to a D3 and if so any probs?

Originally Posted by discojools

So it appears that BFG KM2MTs 265/70/17 (804mm diam)or 245/75/17 (800mm diam) are legal now.
Any body fitted these sizes to a D3 and if so any probs?

Many of us in the West have fitted the 265/70/17 size to the D3, as our rules on oversize tyres for 4x4's have been more lenient in the past (although it now looks as if Victoria has adopted the NCOP guidelines).

With this size, at max articulation you'll barely/slightly notice a rubbing of the rear tyre on the front of the wheel-well plastic lining. How much varies with the make of tyre (as they're not all exactly the same size). However, it's not significant.

Cheers,

Gordon

I believe you can fit the 265/70/17 without mods but havent done it yet myself.


edit - gordon just beat me to it - doh!

Whilst many of the posts here have been about the tyre size/legality/rubbing, etc. no mention has been made about putting a 265 section width on a 7 inch rim.

Check Car Bibles : The Wheel and Tyre Bible Page 3 of 4 under the title An ideal rim-width calculator and a 265 needs a 7.5 inch wide rim as a minimum. Also all major manufacturers will specify a rim width range for each of their tyre sizes usually found on their web site.

I currently run 245/70x17 tyres and the speedo indicates the vehicle speed almost perfectly (according to the GPS) whereas it was 5-7 km/h optimistic before changing to the 245s.

Just my two bob's worth...

Originally Posted by LeighW

Whilst many of the posts here have been about the tyre size/legality/rubbing, etc. no mention has been made about putting a 265 section width on a 7 inch rim.

Check Car Bibles : The Wheel and Tyre Bible Page 3 of 4 under the title An ideal rim-width calculator and a 265 needs a 7.5 inch wide rim as a minimum. Also all major manufacturers will specify a rim width range for each of their tyre sizes usually found on their web site.

I currently run 245/70x17 tyres and the speedo indicates the vehicle speed almost perfectly (according to the GPS) whereas it was 5-7 km/h optimistic before changing to the 245s.

Just my two bob's worth...

BFG website says 265/70R16 Mud's are OK on 7.0" to 8.5" rims - makers recomendation rules