# Axle Weight Formula

Discussion in 'Tech/Mech General' started by GEOFFs125, Sep 15, 2009.

1. ### GEOFFs125

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Hi all, not sure if this is the right forum for this request but here goes.

Does anyone know the formula for calculating the effect on both front and rear axles when weight is added to the rear of a motorhome with a large overhang. Its been a long time since I went to school and some of my brain cells are now frazzeled with age and the occasional beer or two.

Thanks:thumb:
Geoff

2. ### hilldwellerFunsterLife Member

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A long time for me too but......

Assume it pivots on the front axel.
The torque is F*W where F is front axle to weight W.
Effect on rear is torque divided by distance = F*W/G where G is the gap or wheelbase.

Assume it pivots on rear axle.
Torque = down at back = R*W. R being rear axle to Weight.
Lift up at front is RW/G. G being the same gap.

See if that produces sensible numbers.

3. ### GEOFFs125

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Thanks for that, your thinking is on the same wave length as mine.

Correct me if I am wrong: Vehicle has a overhang of 2m and a wheel base of 6m
Therfore, if a weight of 220 kg is placed at the rear, the weight on the rear axle will be

(8 x 220) diveded by 6 = 293 kg

Geoff:Cool:

4. ### hilldwellerFunsterLife Member

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Looks good to me.

Worse your front wheels go lighter by 70kg. Bad news with FWD.