| Author | Message | ||
     richard george yeaman Prolific User Username: richyrich Post Number: 207 Registered: 4-2012 |
A few Months ago I fitted a pair of New rear springs to a friends 1970 Silver Shadow when I had removed the old ones I was surprised to see that the New ones were 30mm shorter than the old ones so if you are about to fit New springs just give them a measure might save you some time. Richard. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 479 Registered: 5-2012 |
Hi Richard This may be a silly question, but did the shorter new springs cause the ride height to be too low. I ask this as it is conceivable that although the springs were shorter, they may also have been stiffer which would compensate. Also, can you remember how long the replacement springs were? Regards Geoff | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 3089 Registered: 4-2003 |
Indeed, there is a big difference between spring specifications for these cars from new. The Australian-spec Colonal ones are nowadays preferred for all replacements. They have a shorter free-length but are much stiffer. The ride height remains unchanged. If you fit those, either fit a 34mm Turbo R front antiroll bar or remove the rear antiroll bar or preferably both actions unless you are prepared for some spectacularly rude handling especially on wet roads. With the stiff rear springs, handling would be very scary if the rear antiroll bar were not deleted (as was done from new for all cars with Colonial springs). Even with a Turbo R front antiroll bar (34mm) the cars are skittish unless the rear antiroll bar is removed. My 1972 T-series is very well balanced with Colonial springs, never a rear antirollbar, and 34mm front antiroll bar. BTW, with the stiffer rear springs, the height control system is only called upon in extreme load conditions. RT. | ||
| richard george yeaman Prolific User Username: richyrich Post Number: 208 Registered: 4-2012 |
Hi Geoff yes the ride height was noticeably lower than what was expected they were bought from Flying Spares and would have benefitted from fitting some shims or spring assisters this particular car has now been sold. Perhaps someone might know of some other way maybe Richards Australian spec or some company that would make them to order. Richard. | ||
| Bob uk Unregistered guest Posted From: 94.197.122.87 |
Were the coils and dia and dia of the wire the same. I thought that there are three spring choice soft, mushy and mushy soft. Or colonial, UK spec and USA boulevard cruising. My springs are a bit limp and scabby. I have rubber coil separators which actually works better than I thought they would they cost about £20. Ultimately I will have to fit new springs and think colonial springs would be about right for Dorset UK. Colonial how quaint. Maybe the standard spec for Wales is colonial. Australia has two extra choices crikey and struth. And if one sees the size of some of the pot holes in Dorset struth is tame and it's more like ringing bell. A company near me called Hawkings Springs makes springs to order and two car spring jobs are the norm, where as others want an order of a hundred. I know a little bit about spring rates and basically the weight each corner and how much the suspension and thus the spring should compress is about 90 % of the calculations for spring rate then it's get complicated working out wire diameters number of coils helix angles free length fortunately the spring guys at the factory work that bit out for you. I saw some big coils wound for a railway locomotive and they wound the wire on a machine cold and then heat treated the coil. The winding bit took about 1 minute. The heat bit takes longer because the steel has to be stress relieved by heating and holding the temperature and cooling slowly. Then the spring is hardened and tempered. The steel used is sometimes called music wire because in the early days the steel used was the same for springs and pianos. The locomotive spring was inch dia wire so it would have been a funny piano with strings that thick. Nowadays the steel is a bit more sophisticated than that. Rolls Royce developed and patented a lot of special steels for springs and other stuff. Rolls Royce is and has been a global leader in materials science. The cars were a sideline. Horologists still use piano wire for springs. (Message approved by david_gore) | ||
| richard george yeaman Prolific User Username: richyrich Post Number: 209 Registered: 4-2012 |
Bob I checked on Flying spares on line parts list and they are listed as aftermarket. So therefore they could be as different as day and night, My own rear springs are original good second hand ones fitted with coil rubbers also I am quite satisfied with this arrangement, when I bought the car the springs were shot and the car was sitting high Via the use of the self levelling rams that I at that time didn't know anything about Bill Coburn used the term Praying Manta to describe this position. If anyone has any helpful information regarding sourcing suitable Springs I am sure readers this forum would be in that. Richard. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 483 Registered: 5-2012 |
Richard Thanks for that information. I am currently in the process of ordering rear springs from Coil Spring Specialties here in the US. FS was going to be my fallback position but not now. The whole point of replacing the rear springs is to get the correct ride height. Thanks for the heads up. Geoff | ||
| richard george yeaman Prolific User Username: richyrich Post Number: 210 Registered: 4-2012 |
Geoff I had three old used springs in my scrap pile I measured them the steel wire diameter is 18mm the lengths were 516mm 525mm and 530mm the last two were from the same car a 1970 car the other from my own car 1974 apparently the spring on the drivers side and same side as the fuel tank has to be stronger or longer to allow for the weight of the fuel and the driver when without passengers find out as much as you can before ordering new ones hope this helps. Richard. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1060 Registered: 6-2009 |
Geoff, What Mr. Yeaman says makes perfect sense as I think about my two cars. SRH33576 was a home market car with the gas tank under the boot and mounted on the right hand side of the car. You'd end up with significantly more weight there when the tank was full than when empty. Still, though, I don't know how, exactly one would be able to compensate for this strictly via the use of a different spring. It would be problematic at one extreme or the other of fuel tank capacity without something else at play (the height control on the right, I'd think, as the two rams operate independently of each other if necessary). The fuel tank in LRK37110 is centrally located behind the rear passenger seat and does not present the same sort of weight balancing issues. I can't recall whether your car is a home market vehicle with an underboot fuel tank or a US delivery vehicle with a behind-rear-seat fuel tank. If you want or need for me to remeasure anything on my spring set, which was never installed, I'll be happy to do so. Brian | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 484 Registered: 5-2012 |
Brian and Richard - thanks for your really helpful replies. I am fast realizing that these springs cannot be just bought "off the shelf". Another factor, pointed out by Kevin at Coil Spring Specialties is that sometimes the isolator is missing and they will manufacture the spring 2" longer to compensate for this. This weekend I will remove one (and possibly both) springs and carry out some detailed checking and measuring. Hopefully I will be able to order the correct springs on Monday. The fuel tank is an interesting issue. My car, SRX18501, was initially exported to Germany and then found it's way to California, so it is not a US spec car however it is a genuine LHD model. The fuel tank is mounted at the rear, right hand side i.e. the opposite side to the driver. I suspect the replacement springs will be identical however I don't expect the weight distribution to be a big problem on my car. It would be more of an issue on a RHD UK car where the tank is on the same side. Geoff | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1061 Registered: 6-2009 |
Geoff, All I can say is that you would be doing the RR/Bentley SY collector community a big service by publishing the findings of your research with regard to how one goes about determining at least the basic things to look for prior to ordering springs. Somewhere out there must exist a Crewe document that outlines this but, if it does, I have yet to see it or have someone point me to it. Brian | ||
| Bob uk Unregistered guest Posted From: 94.197.122.82 |
A 30 mm packing piece at the bottom of the spring would work but may cause problems with the spring saying put and jumping to one side. Some cars have clamps at the spring ends. A spring that is more than 4 times long than the dia of the spring will be prone to buckling to one side or the other plus as the spring changes length the ends turn relative to each other. The buckling does not damage anything the spring won't take on a curious shape. I have seen on McPherson struts the bottom of the spring bounce over and stab the tyre. Nasty. (Message approved by david_gore) | ||
| richard george yeaman Prolific User Username: richyrich Post Number: 211 Registered: 4-2012 |
I had a look on introcar on line parts list and they have OE rear springs listed at £264.60 each add the Vat @ 20% plus shipping that is a lot of Money for one spring maybe getting them made is the way to go. | ||
| Bob uk Unregistered guest Posted From: 94.197.122.78 |
18mm dia is a metric size. RR are more imperial than metric. Could the spring corrode 1mm away and the spring is really 19mm which is 3/4"? (Message approved by david_gore) | ||
| Bob uk Unregistered guest Posted From: 94.197.122.78 |
Bloody Nora, a pair of springs is the same price as a cheap Nissan micra for your daughter's first car. A hypothetical spring specification. Corner weight is 500 kg. The gap for the spring is 500mm with the suspension fully extended. The preload is 50mm. So free length is 550mm. The gap for the spring at ride height is 400mm The spring compresses 100mm at 500kg. Which is about 300 lbs per inch, in this example ignoring the lever ratio of the suspension trailing arm. Armed with the wire dia and number of coils and a photo of the actual spring plus the above with the SY dimensions instead then the spring engineer will be able to design the spring in minutes. Leaf springs can be reset and reheat treated to as new. I have never heard of a coil spring being reset. Maybe it is possible. Stretch the spring using two tractors. It's so daft it would probably work. It works on pens. (Message approved by david_gore) | ||
| richard george yeaman Prolific User Username: richyrich Post Number: 212 Registered: 4-2012 |
Bob When I measured the springs I used a 5 metre tape not the most accurate for measuring springs it could have been 19mm if you made them today 18mm would be too light, Worn springs do not diminish in length they just loose resistance probably a Blacksmith could fix them if you could find one. Richard. | ||
| Jan Forrest Grand Master Username: got_one Post Number: 660 Registered: 1-2008 |
Thanks, Bob. That's just the specifications the impecunious owner (me) needs to source springs at a more reasonable price! Edit for Ps. I think I will need slightly stiffer springs on the back to take into account the 100 litre LPG tank situated in the boot. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 487 Registered: 5-2012 |
I once asked after the price of rear springs at a local RR dealership here in the US. The quote was $650 per spring, about 400 ukp. If the Introcar springs are genuine OE then 264 ukp sounds quite good. I will be replacing my springs in a about a weeks time with springs sourced from Coil Spring Specialties, which retail at $300 per pair. It will be interesting to see how they compare with what I presume are the original springs on my car and whether I can achieve the ride height I'm hoping for. I will start a new thread on this project when I receive the springs for anyone interested in the results. Geoff | ||
| Hubert Kelly Prolific User Username: h_kelly Post Number: 132 Registered: 3-2012 |
Hi , has anyone ever bought rear springs from brabocars.com they retail for 135 euro each plus vat and transportation. Hk | ||
| Bob uk Unregistered guest Posted From: 94.197.122.82 |
I have noticed with valve springs that tired one's are a small amount shorter barely noticeable often. When there are compressed end to end with a new spring and compressed then the difference really shows. Unfortunately suspension springs are to big and dangerous for compressing in a bench vice. I was estimating £70 per spring so $300 a pair sounds fine. For a 100 litres of lpg and tank I would add 100 kg, 50 kg per side. But the lpg gets used so call it 25 kg per side. If the stiffer colonial setting is used then no extra stiffness may be needed. A few years ago I saw these rubber rings about an inch thick but I can't remember where. The lever ratio looks about 4:1 so an inch will lift 1 and 1/4". That maybe is enough for most shadows with dropsy. If I draw an imaginary line though the sill trim to the rear wheel centre, the wheel centre on my car is 3/4 above the notional line. When the rams correct it the appearance of the car looks much better. It really does make the car look better. The 300 lb I made up for the example I think may close to the colonial spring rate for the shadow. (Message approved by david_gore) | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 488 Registered: 5-2012 |
Hi Hubert I had not come across that website before. Very interesting. I like companies that publish their prices on the website. They must be aftermarket, not OEM, given the price reductions. Geoff | ||
| Bob uk Unregistered guest Posted From: 94.197.122.87 |
When I looked at springs all I found was modern stuff via make and model no rates or spring lengths to get a Clue. However one company www.coilsprings.co.uk. of Sheffield lists classic cars and RR. They export globally. And may all ready have the specifications. They use cnc machinery and have spring software. I thought earlier after looking at pram wheels that the solid tyres would make spring packing. If the trye is cut then it could be made to fit exactly and threaded around the damper rod and under the spring foot of the coil spring is compressed with spring compressor tool. The cup that the spring sits in at the bottom looks quite deep so the spring probably won't jump out unless one is airborne and driving like a mad thing. (Message approved by david_gore) |
