Reasons for "spare"

[G.R.]

Having been looking in various books etc., and seeing several tv programs of early Lemans and Daytona racing cars, I've noticed some of them especially , coupe styles, like the Triumphs(v-8 powered especially), MG's, a couple of Porches, Corvette, and of course the Shelby Daytona Coupe all have a spare tire mounted in the rear deck.
Was this a racing/class rule, for weight distribution, or What?
Somehow I can't picture a driver changing a tire off the side of a track but rather limping into the pits.

Thanks, curious about this

[petek]

I believe they were required to carry a spare and to have enough space for two suit cases (the latter using just being a couple of aluminum boxes rivetted to the back of the car right next to the exhaust pipes and transaxle ... on the 917).

[Bill Wells]

a spare was required. that is why there is a strange 'bump' in the back of decklid near license plate area on the 289 fia cars, so the spare would fit under it in the trunk and the decklid could then be closed. b

[Cal Metal]

Bill:

The reason for the dimples in the trunk of the FIA was for the fitting of the square suitcase, not the spare tire.

[Bill Wells]

Cal..thx, OOPS, makes more sense for it being 'squared' off... . bill.

[Excaliber]

Now THERES some good trivia! I to had wondered about that! I didn't know about the "suit case" rule, how interesting!

Ernie