Just wondering if I will have any clearance problems with 15 x 7 rims running 31 x 10.5 rubber on rear of standard 1970 baja

Depends on the offset of your rims. I have run 10 inch rims with 31's no problem however they had almost no backspace.

Do you have long or short torsion bars? If you have the long bars that sit in front of the tyre then you may rub here if you go bigger than 31's.

Otherwise you may rub in the wheel housing at full compression if the offset isnt right.

Nicko

Just new to this wheel game, can you explain what the offset means, not sure of the torsion bar length, I will have a look, but it will be whatever came standard on a 1970 beetle, there has been no suspension mods done

http://en.wikipedia.org/wiki/Offset_%28wheel%29 


As for the torsion bars. Look at the end caps that cover where the spring plates attach to the torsion bars.

the caps will either have a very small raised section or a tube protruding from them. It will be noticeable.

70 "should' be a long axle swinger not irs. Decide on the wheels you have and go from there. You might be able to get an old tyre fitted at a tyre store. Try ringing around. Probably the best way to find what you want. Remember the guards and ride height can effect clearence.

Most Bajas "Should be" a few things but in my experience it is better to check as most offroad cars have had at least a few mods.

rims have 3 &1/4 offset, rear is a swinger. Nico what rims & wheels do you run your Baja in your profile picture

I Can't remember what was on it in the Avatar pic.

Currently runs Standard wide 5 4.5inch fronts with 195/80r15 the rears are 8 inch Roh rims with Standard VW centers welded in running 275/80r15

The rears have huge negative offset.

10 inch rims just fit under wide Cheetah style baja guards.

As a side note.....Why 10inch rims? extra weight, if you run a big negative offset it will put more load on the bearings and unneccesary for 31's.

Also I found the gearing far too high on 31's

the rear rims I was looking at were 15 x 7 (3&1/4 negative offset) not 10", I was wondering if they would run the same tyres as I have on my hilux which are 31 X 10.5. but sounds like I should drop the tyre size how about 29's

If you have a low ratio box and a larger than stock engine you will be fine. 29's will be more workable

It all depends on the ratios.

My first Baja had no dramas cruising along at all. And it was running 31" rear tyres and a stock 1300 single port engine.
But it had the mid 60's 6V swingaxle box which has a 4.375 diff and 0.89 4th gear.

The standard swingaxle box that you have in you can should be

1st - 3.8
2nd - 2.06
3rd - 1.26
4th - 0.89
Diff - 4.125

This will give you 2474RPM at 100km/h with a 31" tall tyre.
Or 2644RPM at 100km/h with a 29" tall tyre.

If you only have a stock engine (1600 or smaller) it's going to be struggling to push those ratios with a 31". The 29" is a better bet. Unless you were to consider swapping in an earlier gearbox to make use of the lower ratios. But it's a bit of a backwards step just to run larger tyres.

Hope this has helped.


Smiley

Thanks for your advice, if running 29's what width tyre is best suited?

Yep I agree,

I wouldn't go any larger than a 235/75, with stock motor and box.

Why not buy some 15x5.5in Mangles (I'm sure them cheap at Wolsburg Auto in Geelong)
A pair of 27's on the front and some 29's on the rear.

Thanks Rhett, have they got a website? what price were they asking ? What do Mangles look like?

I noticed them advertised in VWMA magazine, Look like stock rims, just wider.