ishan
Part of things
Posts: 370
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Whats the legal issues surrounding chopped springs?
Are they MOT passable?
What does the law say about them, i.e if i get stopped at one of those road side inspections, what will happen?
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As far as I Know they're not illegal, but they are subject to normal safety checks. If yours are super short, it's worth making sure that there's some provision to stop them falling out of place on full extension and that they are seated correctly. I've certainly passed police checks (it was a long time ago though!) and MOTs (not so long ago!) on cut springs, and I can't think of any specific rules other than those regarding any 'normal' working suspension that would prohibit caut springs.
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as long as where they go into the spring seat is square so it locates properly i don't think they can say owt
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2001 HONDA CT110 (NOT RCV)
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slater
Club Retro Rides Member
Posts: 6,390
Club RR Member Number: 78
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Hitting with the stick?slater
@slater
Club Retro Rides Member 78
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They are legal i think. Just don't wire them in as that will cause you problems.
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and make sure you taper the cut end off so it doesn't mash into the spring cup. you need a flat top to the spring.
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Never trust a man Who names himself Trevor. Or one day you might find He's not a real drug dealer.
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and make sure you taper the cut end off so it doesn't mash into the spring cup. you need a flat top to the spring. That depends on the shape of the spring cup. They all need to be cut slightly different depending on where they are going to be sitting. I have said it before and I will say it again. Its not really something I am in favour off, particularly if you are using old standard rate springs. If you are going to cut them you are at least better of starting off with a new and preferably uprated spring. Places like this will make coils any spec or height you need. Admittedly it costs a lot more than cutting but if you are going to be driving your car quickly they are a better alternative. www.coilsprings.co.uk/index.html
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So long as the spring doesn't drop out of the cup the MOT man should pass it. I've also heard that wiring them in place is a no-no, but not sure if theres actualy anything in the MOT handbook about that?
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1941 Wolseley Not Rod - 1956 Humber Hawk - 1957 Daimler Conquest - 1966 Buick LeSabre - 1968 Plymouth Sport Fury - 1968 Ford Galaxie - 1969 Ford Country Squire - 1969 Mercury Marquis - 1970 Morris Minor - 1970 Buick Skylark - 1970 Ford Galaxie - 1971 Ford Galaxie - 1976 Continental Mark IV - 1976 Ford Capri - 1994 Ford Fiesta
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bstardchild
Club Retro Rides Member
Posts: 14,948
Club RR Member Number: 71
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Hitting with the stick?bstardchild
@bstardchild
Club Retro Rides Member 71
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Thanks Richard for that link - might be contacting them if I can't sort my GSE out
I bought a set of lowering springs for the GSE - uprated and should have lowered by 35mm from std....... (GSE springs are already 30mm lower than std Monzas)
The front springs fitted into the strut assembly without the need for spring compressors so I thought - dang thats gonna be low there
The back springs also were a lot shorter but still are clamped when the wheels are jacked off the ground so no worries there then.
What I didn't take into consideration (rather foolishly) is the amount of weight I have removed from the car
It is way too stiff spring rate wise for the new weight of the car!!!
It now sits way up at the front and way down at the rear the exact opposite of how I wanted it.
I'm toying with cutting a coil off the fronts and fitting the std rears back again to see if that improves the stance
I do not want to much about with mixing and matching cos I've had a few bad experiences with dodgy handling when different spring strengths are used front and rear so discounted the option of putting just the std rears back in to level up the ride height
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jabbo
Posted a lot
soy un perdedor
Posts: 1,151
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I'm sure it's perfectly legal, providing they still sit right as mentioned above. My mate cut the springs on my previous car, and he's an MOT man by trade. He's not one of these 'fly by night' types either, he does everything by the book
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it depends whether you're doing it for looks or performance. chopped springs will never enhance the handling of your car, as you've just ruined the spring rate and all the geometry etc that the manufacturer spent millions perfecting. the best you can hope for is to make your car look a lot better, without ruining the handling too much.
i personally would chop springs, but only on daily driver and never on anything that might end up on a trackday.
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Never trust a man Who names himself Trevor. Or one day you might find He's not a real drug dealer.
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Cut springs are not the enemy! A spring with coils removed is stiffer than the same spring before the cut - the 'bar' which the spring is wound from is carrying the same rate, but over less coils and therefore a higher rate per coil. The effective rate can vary once re-fitted, but that's due to geometry not the spring itself and would be the same with an aftermarket spring (aftermarket is where someone else cuts it and then powdercoats it ). I'm not talking about spring seats, geometry changes, spring length or dampers here - all of those aren't about how the spring was created, but about how it's used. Don't confuse production methods with actual application - they are different things.
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coil springs made my 3 inch lowered ones for the 230. i still had to cut some coils off cos it wasnt low enough. my cars been dropped 5 inches and the handling has remained pretty much the same. its going for its first mot, on wednesday, since the chopping, il let you know what he says about them.
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bstardchild
Club Retro Rides Member
Posts: 14,948
Club RR Member Number: 71
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Hitting with the stick?bstardchild
@bstardchild
Club Retro Rides Member 71
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Cut springs are not the enemy! A spring with coils removed is stiffer than the same spring before the cut - the 'bar' which the spring is wound from is carrying the same rate, but over less coils and therefore a higher rate per coil. The effective rate can vary once re-fitted, but that's due to geometry not the spring itself and would be the same with an aftermarket spring (aftermarket is where someone else cuts it and then powdercoats it ). I am soooo struggling with that...... sorry can you explain it in a way a 5 yr old can cope with!!! Please?
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slater
Club Retro Rides Member
Posts: 6,390
Club RR Member Number: 78
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Hitting with the stick?slater
@slater
Club Retro Rides Member 78
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I had to chop my rear springs on the fiesta because even the supposed 'lowered' springs were too high! They go loose in the cups when you jack it up but cant attualy fall out completly. Even stock height springs go loose when you jack it up so that cant be a MOT failure as all mk1/2 fiestas would fail!
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OK, let's work with wood.
A standard 'plank' is about 2" thick and it's a bit bendy - cut a bit off the end and it's less bendy - it's stiffer. That's because it's still 2" thick but over a shorter length. It's probably completely wrong from a physics point of view, but you get the idea?
I'm no engineer, and my background in spring chopping is from a looks and not handling point of view, but the theory was explained to me by an engineer and it makes sense to me.
I'm going to find the old SM article that explains it and gives formulae for working out desired spring rates and lengths to counter-act geometry on different types of suspension.
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slater
Club Retro Rides Member
Posts: 6,390
Club RR Member Number: 78
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Hitting with the stick?slater
@slater
Club Retro Rides Member 78
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My thinking goes like this Imagine the spring like a torsion spring. You cut a torsion spring in half and you get half the 'twist' for a given load right? Coil springs are just torsion springs coiled up so the same principle applys. Half the length of spring and it compresses half the length under the same load as it did before. I think! (i did an essay on it for my physics a-level but don't relly remeber a thing as usal! got a B tho so cant have been far wrong )
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chopped springs will never enhance the handling of your car.... You never rode in my Volvo before the chopping took place then! OK, so a rough road and it's a bit bouncy, but give me a roundabout or sweeping curve and it sticks to the road without the bucket loads of body roll previously experienced. I've been running 4" chopped springs for 15 months and one MOT. I asked the MOT tester prior to doing the job (http://uk.geocities.com/kellysands@btinternet.com/springs.html) and he was OK with it provided the cut ends showed no sign of digging into the spring seats. Rmad and I did the deed 5 months before the MOT and no wear had occured. Still, it's not the best way to get a car low, but hey, it's quick and looks cool. Oh, and if you over do it, your panels will eventually crease, or your 2CV car may snap in half. ;D
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Peugeot 307sw - Suzuki SV650S - MX5.
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slater, that is how i understand it.
Paul
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Thanks Richard for that link - might be contacting them if I can't sort my GSE out I bought a set of lowering springs for the GSE - uprated and should have lowered by 35mm from std....... (GSE springs are already 30mm lower than std Monzas) The front springs fitted into the strut assembly without the need for spring compressors so I thought - dang thats gonna be low there The back springs also were a lot shorter but still are clamped when the wheels are jacked off the ground so no worries there then. What I didn't take into consideration (rather foolishly) is the amount of weight I have removed from the car It is way too stiff spring rate wise for the new weight of the car!!! It now sits way up at the front and way down at the rear the exact opposite of how I wanted it. I'm toying with cutting a coil off the fronts and fitting the std rears back again to see if that improves the stance I do not want to much about with mixing and matching cos I've had a few bad experiences with dodgy handling when different spring strengths are used front and rear so discounted the option of putting just the std rears back in to level up the ride height They quoted me. £150 for a set of springs to whatever height and spec I required for a monza. I now have a pair of lowered/ uprated rear springs but as most of the interior has now gone it is sitting pretty level.
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paul4be
Part of things
'86 Capri Laser, Frontera 4x4
Posts: 395
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If the spring is a linear rate spring and not one of the wierd and wonderful rising rate springs, then the spring rate does indead increase with the amount you chop off. 2 coils of a 10 coil linear rate spring (20% length reduction) will see an effective rate increase of 20% over the original rate.
Wagoneer, when you cut the fronts on the 240, did you heat and reshape the cut ends, or just grind smooth at the cut?
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