17 replies to this topic

[S pack]

I measured the front and rear track on my hatch today. Doing it by my self...I believe i got it fairly accurate but I'm not 100% happy with the accuracy.

Front
1422 1st measure
1412 2nd measure

Averaging them out... 1417mm

as for the rear it's a 9" that came out of a LX Torana.

Rear = 1380mm 1st measure, this is to the out side to out side of the drum.


Do these measurements seam correct ??



Now if they are correct, Working out my rim sizes, I need some help.

Some information to help work it out.

• 1976 LX Hatchback
• Track = Rear 1380mm, Front 1417mm
• Im going with HQ stud pattern,
• 330mm hoppers stoppers on the front.
• I want/ would like, 235/55/R17 front and 255/55/R17 on the rear.
• Guards will be cut, and Wilsons flaires fitted.
• I would like to fill the guards as much as possable.

Now what widths, offset, back spaci should i go with ??


.

Wheel track is actually measured from centre of tyre tread to centre of tyre tread (obviously the steering on the front wheels must be in the straight ahead position) so you cannot get the actual/real track measurement until your wheels and tyres are on the car. The offset of the wheels you get will determine the track measurement.

[S pack]

Im pretty sure track is measured from the centre of one rim to the centre of the other??

Well I suppose that should give you the same result as measuring from the tyres as the centre line of the tyre tread should match up with the centre line of the rim.
Just sharing the way I was shown to measure wheel track many years ago by a suspension expert, he said measuring the track from tyre to tyre was the correct way.

Cheers
Dave

[Lima31]

Easiest way is if your tyres are symmetrical ... get the tape measure tab on one tread edge near the centre of the tyre and measure to the same tread edge point on the other tyre - track is the width as measured between the centre of each tyre.

[ls2lxhatch]

The front track measurement will vary depending on the ride height. The widest track measurement will be when the lower control arms are horizontal.

Camber will also affect the track measurement as the top of the tyres will be closer together than the bottom of the tyres.

I assume the official track measurement is when the suspension is at ride height and is measured from the middle of one tyre to the midlle of the other tyre at axle height.

Chopper or Axistr should be able to confirm

Edited by ls2lxhatch, 26 June 2011 - 06:51 PM.

[S pack]

The front track measurement will vary depending on the ride height. The widest track measurement will be when the lower control arms are horizontal.

Camber will also affect the track measurement as the top of the tyres will be closer together than the bottom of the tyres.

I assume the official track measurement is when the suspension is at ride height and is measured from the middle of one tyre to the midlle of the other tyre at axle height.

Chopper or Axistr should be able to confirm

Yep, vehicle must be at full kerb weight and on level ground to get accurate track measurements. In fact all suspension measurements must be made under these conditions to be accurate.

This is how Roy showed me how to take wheel track measurements.

Track measurement is the distance between the centre of the tyres where the tyres contact the ground. Unfortunately it is hard to get a tape measure between the tyres and the ground. So take the measurements as close to the ground as possible.

On the front wheels take two measurements (because of toe in or toe out), one in front of the tyres contact patch and one behind, now work out the difference between the two measurements, halve the difference and add it to the shortest measurement. This adjusted measurement is the true wheel track measurement.

[Hybrid]

Have you fitted the HQ stubs yet as that will in crease front track width by 50mm and lower the car by same. I found that ride height also plays a factor as the lower the car the less width of tyre you can run in the front, I could only just manage 225 on the front with HQ Stubs and ride height of 100mm to middle of cross member which is as low as I could legally go I had standard HQ mags with zero offset, I never checked it out but maybe with negative offset I could have run more but all the cars with big rubber up front have a higher ride height then I had

It's probably not a good idea to fit HQ stubs unless you want to spend an axtra $400 on Harrop steering arms. The beauty of the Hoppers kits is that it is designed to work with the Torana stubs so that the steering geometry is not altered.

[ls2lxhatch]

So bacically I'm screwed.

As the car is currently a rolling chassie, I can reinstall the diff and take measurements with the car on the ground but it wont be kerb weight unitll the rebuild is finihsed.


There must be some way to work out the measurements, so i can calculate the backspacing/offset/ rims width etc.

With the wheels and tyres fitted i can also mak out how much of the guard to cut.

.

You should be able to get accurate front track measurements by removing the front springs at setting the car at your preferred ride height. One way to do this is to replace the front shocks with threaded rod.

The rear track can be measured with the diff out of the car. The rear track on a live axle does not change with suspension travel.

[ls2lxhatch]

Before measuring the front track check that your suspension bushes are in good condition and make sure you have fitted the front brakes you intend to run.

If you are checking tyre clearance then you need to be aware that with the UC caster the tyre is closer to the firewall than it is with the LX caster.

[ls2lxhatch]

But if I fit the Hopper Stoppers with HQ stud pattern.
How can I find out what the track is as I won’t have rims that fit?

If you measure from the hub to hub (where the rim bolts up to the disc) then that measurement should be the same as a zero offset rim.

The same goes for the diff. If you measure the diff from drum face to drum face and add the offset for each rim then you should get the same measurement as you did measuring from the centre of the tyres on the diff.

HQ stub axles do not have any significant affect on track. The HQ discs do increase track but a HQ stub with Hoppers Stoppers will have the same track a the LX stub with the same Hopper Stoppers hub.

Edited by ls2lxhatch, 28 June 2011 - 07:44 PM.