Alfa Romeo Giulia TI, Giulia Super & 105 Berlina Boot Spring [403.17200]

Alfa Romeo Giulia TI; Super; 1750 & 2000 Berlina Boot Spring      P/N 403.17200    Sold singly – discount for 2 purchased together [see order quantity panel]

Spring for the boot [trunk] lid on all 105 Berlina cars

Giulia TI; Giulia Super; 1750 Berlina; 2000 Berlina

Replacing the original 105 14 56 172 00 A R Springs.

These springs have been produced after a long period of investigation into the requirements to ensure they perform exactly as Alfa Romeo intended originally.

“The lid would pop from the initial locked down position and then will raise with minimal effort by hand, and can be stopped, and will remain, at any position from closed to full open as required”.

Unfortunately as most owners are well aware, this situation only lasted for maybe a couple years of operation [if you were lucky] before a prop was required to hold the lid up or extra springs were jury-rigged alongside the originals in an effort to stop the lid coming down on an unsuspecting person’s head.  

Our springs can be fitted to any of the 3 positions provided on the support brackets to enhance the lift if so required by the owner

We recommend the springs be purchased and fitted as a pair. [Discount applies]

Our springs have been computer designed to travel through the functional arc of the hinge without ever reaching the critical stretch position that causes any spring to take and hold a “Set” which is the problem with the design of the original springs fitted to these Alfa Romeo sedans.

As hardly any thought is given to these springs other than to condemn them as useless, no-one has taken the time to ascertain the actual reason for the problem.

Virtually no-one realises that the reason for them failing is that they are in a state of full tension ALL THE TIME THE LID IS CLOSED.

They are only ever, almost – but never quite, in a relaxed state when the lid is fully raised. Consequently, if the spring is at, or very nearly at, its critical stretch or extension position for virtually all the time, this is why they fail. 

Our springs have been designed and manufactured right here in Queensland from Australian spring steel. We studied the reason for the problem and worked through all the computations to compensate for the causes.


 

For those interested, the following are the calculations required to determine the requirments of extension springs

CALCULATIONS

Close coiled spring

R = Mean radius of the spring

N = No. of Coils.

d = diameter of the wire.

N = Shear modulus of the spring materials.

W = Load applied.

= Deflection

Spring Test Standards used to develop our springs

Springs have individual design specifications, derived from materials used, manufacturing method, and finish. These characteristics each have their own industry standard specifications in turn. But the only way to ensure performance to specification is to test in line with standard test methods for springs. Using BS 1726-2: Guide to methods of specifying, tolerances and testing, Extension springs and Cylindrical helical springs made from round wire and bar.