Anyone remember when they became popular? Trailors sem to get them first.I remember being told not to drop one on their end as they would snap 
Well it was true as a lad was getting one out of the van at Richard Reads and he dropped it 
leylandlover:
Anyone remember when they became popular? Trailors sem to get them first.I remember being told not to drop one on their end as they would snap
I thought they were great the single leaf springs,and coupled with tubeless 11.22:5 wheels you didnāt half cut down on weight and failures and considering the many single leaf trailers we ran we had very little trouble with them,the odd locating āpipā failure from memory and only a couple of broken ones on the same side of a tipping trailer but this was down to the idiot driver,nothing more.What we did when I bought secondhand trailers on multi leaf springs we converted some to mono leaf and then used the spare multi leafs to exchange those multi leafs that failed on other trailers which still had multi leaf springs.In this way we steadily worked our way through that part of the fleet without the need to purchase new multi leaf springs.Hope my explanation is understood ! Phew ! Cheers Bewick.
Bewick:
leylandlover:
Anyone remember when they became popular? Trailors sem to get them first.I remember being told not to drop one on their end as they would snapI thought they were great the single leaf springs,and coupled with tubeless 11.22:5 wheels you didnāt half cut down on weight and failures and considering the many single leaf trailers we ran we had very little trouble with them,the odd locating āpipā failure from memory and only a couple of broken ones on the same side of a tipping trailer but this was down to the idiot driver,nothing more.What we did when I bought secondhand trailers on multi leaf springs we converted some to mono leaf and then used the spare multi leafs to exchange those multi leafs that failed on other trailers which still had multi leaf springs.In this way we steadily worked our way through that part of the fleet without the need to purchase new multi leaf springs.Hope my explanation is understood ! Phew ! Cheers Bewick.
Hey, didnāt give that problems with the MOT, before about 20 years we had a certificate that gave all details about the trailer. How many springs and so on, even later if we mounted spring parking breaks against a cable it wasnāt allowed. You only could do that if the constructor did it by his self.
Now its beter without that certificate on old trailers you can change some things, most young MOT men donāt know today old trailers systems.
Of course since the old ceriticate disappeared it gives an other system to control and has the same effect on new ones and stays to check for live. It gave a time we couldnāt even built in an other engine without certificate.
Eric,
Father and I changed the front springs for mono leaf + helper on a X reg Erf b series unit he said it was a great improvement,this would be around 1989 .
Whatever their advantages in terms of weight they were not at all successful on the rough roads of the Middle East. I had several fail on me and they all snapped right at the U bolt. Donāt know what that tells us. Also out there there were lots of little workshops that could repair a leaf spring but, obviously there was nothing they could do with a mono. I did have one Old Boy who thought he could weld it but that ended in tears.
David
Early 80ās I was following an artic on the 74 sth by Kirkpatrick, hitting a pothole there was a bang and 2ft of monoleaf comes hurtling past me,his rear axle is bouncing all over the place. I got past him and flagged him into a lay by and showed him what had happened to his empty trailer. It was one of Roweās from Tamworth, I told him the trailer axle was bouncing everywhere, his reply floored me he said thanks for letting him know and he would get it fixed when he got back to Tamworth Never knew if he made it !!
David Miller:
Whatever their advantages in terms of weight they were not at all successful on the rough roads of the Middle East. I had several fail on me and they all snapped right at the U bolt. Donāt know what that tells us. Also out there there were lots of little workshops that could repair a leaf spring but, obviously there was nothing they could do with a mono. I did have one Old Boy who thought he could weld it but that ended in tears.David
We actually had very few problems with springs in Saudi, operating throughout the Magic Kingdom from out of Dammam. Yes, the roads could be potholed (bury a camel in some of them!) and off road 40 or 50 miles into the desert sometimes on washboard like hard packed sand. We did tend to overload slightly now and then too!
We had a mix of British and American trailers. I seem to remember quite a few American ones which looked like mono leaf, but had a couple of āhelperā springs.
We always put down the lack of problems to the fact that it never got very cold.
Oh, and of course if you did get a problem, all you did was take the wheels off and chain up the axle and carry on, empty or loaded!
John
David Miller:
Whatever their advantages in terms of weight they were not at all successful on the rough roads of the Middle East. I had several fail on me and they all snapped right at the U bolt. Donāt know what that tells us. Also out there there were lots of little workshops that could repair a leaf spring but, obviously there was nothing they could do with a mono. I did have one Old Boy who thought he could weld it but that ended in tears.David
Your right about the breaking by the u-bolts Dave, if not there then sometimes in the center by the location ā ā ā ā ā ā . The makers used to say always fit a new spring with new delron (?) liners which they reckoned would stop them snapping and also help the u-bolts to retain their tightness.
I know that as a mechanic it was a far easier job to change monoās than multiās !!
Steve.
David Miller:
Whatever their advantages in terms of weight they were not at all successful on the rough roads of the Middle East. I had several fail on me and they all snapped right at the U bolt. Donāt know what that tells us. Also out there there were lots of little workshops that could repair a leaf spring but, obviously there was nothing they could do with a mono. I did have one Old Boy who thought he could weld it but that ended in tears.David
On my first trip out to Baghdad in '75, there were three of us with Eurofleet Rental box vans on monoleaf springs.
We were all fully freighted with sanitaryware and had no trouble until we had to take the diversion with a military ā ā ā ā ā ā over Mardin.
Most of those roads were unmade and one of us broke a trailer spring causing the trailer to lean something awful. We jacked it up and managed to fit a block of wood between the axle and chassis, luckily the radius rod kept the axle tracking OK.
We got down to Baghdad and after tipping told our agent we could do with some spares to repair this spring.
Obviously, monoleaf springs were unheard of in Iraq in '75, but our agent took us to the street of a thousand clutches where we were able to buy sufficient conventional spring leaves and a centre bolt t make up a multileaf spring to get us home.
We all know what a steep learning curve the first trip is, and this was just one thing to note, on future trips we always carried a couple of spare monoleafs.
At the same time my colleagues and I were heading for Baghdad, another of our lads was heading for Teheran, again with a load of bogs, and he managed to get through to base on the 'phone from Tahir, to say he had broken two springs on his trailer and was immovable.
Who could get to him to replace the broken springs?
Knowing the fearsome reputation that Tahir and the surrounding towns had, we feared for his safety, but we all know that where ever you are in Turkey, you need not go far to find a good welder!
Anyway, the driver, Ian Rollinson, was well looked after and a welder was found who was able to do a good enough job to get the trailer mobile well enough to finish the trip.
As far as I was concerned,as an operator,there was āno contestā the tubeless/mono leaf tandem trailer was made up of 20 pcs whereas the Tubed/multi leaf tandem was made up of 52 pcs and if you include all the spring leaves it was a minimum 76 different components anyone of which could fail ! Cheers Bewick.
Of course thatās right Bewick but the failure of just one part far away from home was catastrophic with the monoleaf but the multi could fail in several leaves and still be operable.
David
Good points made by Bewick and David.
Referring to multi leaf springs, I remember a former employer (leylandlover will know who) met one of my workmates (he will know this one, too!) as he was turning into the yard with a definite ālistā to starboard. On examining the rear springs the boss found four broken leaves. āDidnāt you check your springs before you left this morning?ā he enquired with the usual red face. āNo, I donāt look at them, then I donāt worryā came the reply!
There was IIRC a half way kind of spring between the multi leaf and the Mono which was called the āparabolicā and IIRC was made up of 3 leaves but I never fancied them,the Mono was the spring for me and we had next to no trouble with them although we did only operate on A Class and M/way roads mainly this fact may have helped a bit ! Cheers Bewick.
Bewick:
There was IIRC a half way kind of spring between the multi leaf and the Mono which was called the āparabolicā and IIRC was made up of 3 leaves but I never fancied them,the Mono was the spring for me and we had next to no trouble with them although we did only operate on A Class and M/way roads mainly this fact may have helped a bit ! Cheers Bewick.
At Humber McVeighs they had quite a few 36ft trailers on airbags,I remember one occasion,I coupled to a trailer,air lines connected,only to find one of the bags would not inflate,reversed over the pit at Grimsby,a trailer fitter renewed the bag in less about 30 minutes,still within my hours to get back to Salford.
David
How did you find tyre wear on the monoleaf compared to the multileaf Bewick?
I found that the multileaf had a bit more give in them and didnāt tuck the tyres under so much in tight turns.
And before anyone whines about screwing it around being unnecessary, you donāt have much choice on a hairpin bend!
Bewick:
There was IIRC a half way kind of spring between the multi leaf and the Mono which was called the āparabolicā and IIRC was made up of 3 leaves but I never fancied them,the Mono was the spring for me and we had next to no trouble with them although we did only operate on A Class and M/way roads mainly this fact may have helped a bit ! Cheers Bewick.
Parabolic springs are still used on the front axle of most trucks today, the usual alternative being air.
A parabolic is a multileaf spring, using less but thicker leaves, and the only friction point between the leaves is at the ends, whereas on proper multileaf springs the friction between the leaves is over the whole length.
It gives a softer ride with the initial springing being on the main leaf, until further compression brings the top leaf down onto the outer ends of the second leaf.
This type of spring is well known among 4 X 4 fans (like myself), as an aftermarket upgrade to your Land Rover, so instead of the hard ride from cart springs, the ride is more like one would get from coil springs.
Tell me Iām wrong but I never saw parabolic springs fitted on a trailer - or monos on a tractor unit come to that.
David
Never saw a unit with monoās on but i had a tipping trailer with 3 leaf parabolics on, and iām sure i have seen a flat trailer with them on
I think most trailers from the early 80s on had parabolic springs.