[alfa] Re: Duetto Wheel Offset

[Stefano.Iachella@xxxxxxxxxxxxxxxxxxx]

>My Duetto has aftermarket alloys fitted.  14X6J wheels with 195/65-R14
tyres.

>When laid on a flat surface, tyres fitted, the mating face measures 140mm
to
>the inside and 60mm to the outside.  I assume this gives an offset of 70% ?
>How does this compare to the correct offset for a 1600 Duetto ?

>There is also a 6mm wheel spacer fitted to both front hubs.

>If the wheel offset is close to correct, I'll have the centres machined for
>grease cap clearance.  If not, I'll offload the wheels, which I suspect are
>meant to fit a modern FWD Ford (?)

Wheel offset is measured in mm, not %. It is the distance from the mating
surface of the wheel to the centerline of the wheel. Some people use a 
measure called backspace which is mating surface to inside of the wheel, not
the tire. Your 140mm measurement is the backspace, but measure it again,
this
time go to the rim, not the tire. Then you must subtract 1/2 the wheel 
width from this measurement to get the offset. So 6" = 6*25.4mm = 152.4mm. 
1/2 of that is about 76mm. Wheel spacers subtract directly from the offset.

If your inside/outside relationship with tires is about 70%, the wheels
alone
are probably close to that percent, so the backspace is probably about 106mm
without the tires. 106mm - 76mm = 30mm. With the spacers = 24mm. (Approx).

Offsets for 14x6 wheels on Alfas of this era are about 22mm. 14x5.5 old
steel
wheels usually come with an offset of 38mm. The spacers were probably put in
to bring them closer to 22mm. 

Stefano
Walnut Creek, CA
--
to be removed from alfa, see /bin/digest-subs.cgi
or email "unsubscribe alfa" to majordomo@domain.elided