rear springs

[IanClayton]

I've been f-t-g about with A7's for a while now and never discovered the answer to the following question/s. It may be that the answer has been solved on this forum before -if so can someone enlighten me?

In 1930 'stronger' rear springs were fitted ( I suppose for the heavier steel bodied cars) and then in '34 , I'm advised,the offside one was made even stronger. Don't know if our late (C series) RP has this as never investigated but 'Aine' has "Nobby" helpers as well to cope with our Irish potholes!

Just what were the physical differences and was this practice continued throughout the subsequent 'Jewel' sevens?

[JonE]

Early rear are 6 leaves and the later (still alloy) saloons saw 7 leaves I believe - so that would tie with 1930? The Bill Sheehan notes suggest SWB up to 6" base of lower leaf to centre of spring pin 'ole and the LWB high frame +1/2 inch.... as MAX figs. I've just taken off springs which were an inch difference in camber and interestingly one was about a centimetre longer from securing bolthole to spring pin. So it's not just getting them sit right.... but making sure the wheels sit as a rectangle and not a trapezoid!

I'd be interested the know the exact changes too - are they noted in the 'Changes' book??

[squeak]

What is your source for the 'Bill Sheehan notes' Jon?  Bill has identified camber errors  stemming from the unorthorised copying of his notes in the Companion many, many years ago.

Edit: Having just looked up my copy of the companion I find I have a hand written note claiming for 1924-5 rear springs, 5 leaves and 6.5" camber

[JonE]

I'd forgotten where I saw it so it's good that its posted on FB and here. Ian and Bill had both been trying to get over the problems of the Companion and the lack of correction when it was updated.

http://www.da7c.co.uk/technical_torque_a...rMb5hUeecs

So it sounds like there must have been a move from 5 to 6 after 1925 perhaps?

[Parazine]

This is one of the springs from my 1926 (December) Top Hat. An inaccurate way of measuring set but gives a figure somewhere about 6".

Seven leaves.


   


   

[IanClayton]

Supposedly the stronger offside rear was to help with the pre-war UK road surface camber I think. so maybe all Sevens from that time on had this feature - Dave Martins changes list shows a separate part number but I've never looked when changing springs in the past and maybe offside springs have been wrongly used on the nearside?
 
Maybe just an adjustment in temper?

ian

[Malcolm Parker]

I am confused!
Normal roads have a camber which means that they are higher in the middle.
If you abide by Nicholson's advice in The Austin Seven Book page 17, you will drive in the middle of the road to equalise the load on the springs.  If however you want to survive another day you will keep to your side of the road, in which case the side nearest the edge of the road will be more loaded due to the camber.  I would have thought therefore that in the UK, the left rear spring should be the stronger of the two?
I think all that matters is that the springs are a matched pair and of the correct camber for the model of A7. As has been discussed earlier, unless the car is to be used for trialling or subject to heavy loading, rear springs with slightly less camber are a good thing.

[andrew34ruby]

I always thought the 'stiffer spring was near the middle of the road to cope with the weight of the driver. Yes, sometimes there is a passenger, but there is always a driver.

[Alan]

This, I find remarkable. If I was going to try to compensate for driver mass I’d do it with camber (or packing) not spring rate. Why would you want different rate springs on either side of the car? Are you sure about this ?

[David Stepney]

Series Landrovers have different springs side to side front and rear. They have different part numbers too. If one puts them side by side, the offside springs are slightly more cambered than the nearside, so that, when fitted, to offside is slightly higher than the nearside This is for a right hand drive vehicle. Left hand drive vehicles have different part numbers again.

I have never found out why this is so. You'd have to be a B***y heavy driver to depress the springs My 8 1/2 stone makes no difference to the stance of the vehicle whatsoever.