Prognosis . . . Depression

A sequence of events :

. Visit to the Isuzu Truck Distributor : (conversation goes a bit like this)
"Can I put Super Single Tyres/Wheels on this truck?"
"No Worries Mate! We do it all the time!"
"Could you sell me a new truck with these tyres?"
"Sure Mate. We did 5 of them last week!"

. Visit to the tyre dealer :
"I want to order 5 new Super singles and rims to go on that truck."
"No Worries Mate! We do it all the time!"
"They cost HOW much?? Oh OK. Do it anyway."

. Fit the tyres - I love those tyres - the truck is SO much nicer!

. Engineer arrives - explain the torsion free frame :
"No Worries Mate! It'll work great. So - how did you get compliance for the tyres?"
"I haven't yet. I was going to do it all at once with the Motorhome inspection."
"OK. What size were the originals - what size are these? WHAT size are these??? No chance mate - can't be done!"

. Ring the Isuzu Distributor
"About these Super Singles - where to I get them inspected?"
"Bring it in here Mate. We are certified to do our own inspections."
"and you'll give me a compliance certificate???"
"DUH! You'll have to get that from an engineer"
"So what do you guys do?"
"We make sure it complies with the compliance plate he issues."
"So do you get compliance plates for all these type of tyres you fit?"
" Nah Mate. We don't bother for them. Everybody does it'"
"Do you know that everyone of those vehicles does not comply, can be put off the road with a red sticker and that ALL insurance is null and void?"

CLICK . . . BUZZZZZ ......

Hmmmm....

OK Find "the" engineer certified for Heavy Truck Modifications. Somehow I know what's coming! Really nice guy - tried to break it as gently as possible..

Somebody (!!) has to analyze
. Braking with larger moment arm due to increased rolling radius,
. Suspension dynamics with increased unsprung weight,
. Steering geometry affected by lack of convergence of "king pin inclination", castor angle etc.
. Increased forces within the steering elements (especially with uneven braking),
. Changes in stability due to changes in chassis height, track width, overall width,
. etc., etc., etc..

Isuzu has in all previous cases declined to participate - and no-one around really has the equipment etc.

"Hello. Is that the truck wrecker? Can I please buy my old wheels and tyres back?"