Author Topic: S1 front spring specifications  (Read 290 times)

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Offline Fulvia-hf

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S1 front spring specifications
« on: Sunday,October 09, 2022, 09:32:21 PM »
Hello,
my S1a is steadily coming together. I've managed to source a set of NOS Koni front dampers. They are for 1.9" ID springs. Can anyone tell me the specifications for the front springs? uncompressed length, number of coils and strength? If possible also if the OEM specifications need to be changed for modern usage.
Cheers,
william

Offline bjthomp

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Re: S1 front spring specifications
« Reply #1 on: Monday,October 10, 2022, 06:55:35 AM »
Spring specifications are detailed on Page 15 of the Technical Data Section of the Workshop Manual. Whether they apply to an S1A is another matter, since the book was published after the introduction of the S2.

Offline Bryan Boyle

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  • 1974 Europa JPS #142 3291R
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Re: S1 front spring specifications
« Reply #2 on: Tuesday,October 11, 2022, 07:53:27 AM »
Probably not enough for you, but, the online parts manual has the following.  Specific details are missing since they weren't necessarily published or tracked:

S1 prior to chassis number 480
No. of Coils      15 (measured from 460355)
Diameter, outside   6.6cm (2.59375")
?

S1/S2 fom chassis number 480 to 2383
No. of Coils      14 ?
Diameter, outside   4.8cm (1.875")?
?

S2 after chassis number 2584 to September 1971
No. of Coils      17
Wire diameter      8.83mm (0.348”)
Length, free      32.38cm (12.75”)
Length, fitted      19.68cm (7.75”)
Rate         1.15kg.m (100 lbs.in)
Load, fitted      227.3kg (500 lbs)
Diameter, outside   6.4cm (2.5")

S2 after September, 1971
No. of Coils       14.75
Wire diameter      10.16mm (0.400")
Length, free      34.90cm (13.75")
Length, fitted      ?.??"
Rate         ??? lbs/in
Load, fitted      ??? lbs

TC/TCS
No. of Coils      13.5
Wire diameter      10.16mm (0.4”)
Length, free      31.77cm (12.51”)
Length, fitted      20.01cm (7.88”)
Rate         1.33kg.m (116 lbs.in)
Load, fitted      224.5kg (537.08 lbs) 
Bryan Boyle
Fall River MA
Morrisville PA
Commercial Pilot/CFII/FAA Safety Team
Amateur Extra Class Operator & FCC Volunteer Examiner
Currently working on 3291R, ex 444R, 693R, 65/2163, 004R, 65/2678
http://www.lotuseuropa.us for mirror of lotus-europa.com manual site.

Offline Fulvia-hf

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Re: S1 front spring specifications
« Reply #3 on: Tuesday,October 11, 2022, 11:35:46 AM »
Thanks for these answers but unfortunately I cannot order a set of the correct springs with this data. I hope there is someone who has solved this problem and has fitted good 1.9"ID springs to his S1 or early S2 front shocks.
Thanks in advance!
William