Giubos Hookes and Cardan

[C M Smith <cmsmith@xxxxxxxxxxxxxxx>]

It is obvious why English speakers commonly misspell the Italian Giubo, or 
Giulietta for that matter. There are no English words that are spelled 
giu...and there are many English words spelled gui... For an Italian the i 
after the g gives the soft sound to the g. In English there is no 
particular rule for soft or hard g, but a u after the g universally gives a 
hard g.

Another design using Giubo's was the 68-70 Triumph GT6 for it's halfshafts. 
Curiously, I recall they used a Hooke's joint at one end of each half shaft 
and the Giubo at the other, the non constant velocity aspect would seem not 
to bother the boys at Standard Triumph as I think they were looking for a 
cheap way to accommodate the plunge of their cobbled up lower wishbone 
upper transverse leaf spring irs (makes you shudder just to think of it.) 
The Giubo's were made by Dunlop, presumably under license. This was a less 
than successful adaptation of the Spitfire derived swing axle, and curious 
because they already had a perfectly acceptable double Hooke's joint 
halfshaft suspension on their 2000 saloon series, with the same engine and 
transmission which also found its way into the TR4A, TR5, TR6 and 2500 
saloons. I say less than successful because the GT6 reverted to swing axles 
for 1970 and later cars, rather than true irs the car actually needed to be 
successful. Then the TR7 went to a live axle for gawsh sakes, superior in 
handling to the TR6 but a step backwards nonetheless. No wonder they went 
broke when you consider what a horrible mish mash they had for sale.

I always thought the Giubos used on the rear of the GTV6 and presumably the 
Milano were a bad idea given the ready availability of Birfield/Rzeppa CV 
joints, now pretty much universal these days for constant velocity 
applications such as driveshafts (pardon the pun).

As for the estimable Mr Hertzman's presumably rhetorical question about 
Cardan and Hooke's joints it is true that those names are treated as 
interchangeable in English for the standard cruciform universal joint. If 
Cardan's design predated Hooke's then possibly Hooke reinvented it 
independently, or more likely given the times, the English Hooke would 
simply have claimed he invented it as there was no recognition of foreign 
patent or similar intellectual property rights. Indeed, it was an 
Englishman's patriotic duty to steal foreign designs whenever possible, as 
was true of foreigners.

A Giubo's most technically interesting characteristic would be it's ability 
to act as a constant velocity joint in that the rubber membrane would allow 
the automatic bisection of included angle required for CV operation. It 
took another Italian (and a German, and an Englishman) Rzeppa quite a while 
to devise a metal device that would give true CV operation and make fwd a 
cheap and practical design.

Does anybody still use the cruciform universal joint anymore and why???

Cheers


Michael Smith
White 1991 164L
Original owner
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