unsprung weight

[Eaton Dave <dave.eaton@minedu.govt.nz>]

in response to the thread i started questioning the wisdom of simply
upsizing wheels and tyres without any consideration for the effects on the
handling of the increase in upsprung weight, someone asked about the actual
increase in weight of larger wheels.

i've forgotten to send this reply (it pays to check your "drafts" folder
from time to time)...

it is extremely difficult to find this information about wheels.  the
manufacturer's don't seem to publish this information (wonder why not?).  in
the end, and using the tsw "hockenheim r" as a guide, i got the tsw importer
to hand weigh a couple of wheels..  these are actual weights:

the 15x8 et35 weights 8.4kg,
the 17x8 et35 weights 10.8kg

thus an increase of 2.4kgs (5.3 pounds) per wheel.  to put it another way,
by going +2, you have increased your unsprung weight from the wheel alone by
30%.

of course, the tyre weight would be on top of that.

dave
'95 rs2
'90 ur-q