American vs Australian chassis differences

Wheels, Suspension, Brakes & Tyres questions and answers

Moderators: timk, Stu, zombie, Andrew, -alex, miata

User avatar
dmad_dood
Fast Driver
Posts: 275
Joined: Wed Dec 19, 2012 8:16 pm
Vehicle: NA8

American vs Australian chassis differences

Postby dmad_dood » Sat May 03, 2014 10:37 am

Hi guys. Just a quick question is there any difference in the American NA8 chassis vs the Australian. More specifically the rear half. I want to buy a tow bar from the states but am wondering if its going to fit my na8 here?

Thanks,

Jono.
Red NA8..

User avatar
zossy1
Racing Driver
Posts: 1979
Joined: Wed Aug 18, 2010 8:48 am
Vehicle: NA8
Location: Southern Highlands, NSW
Contact:

Re: American vs Australian chassis differences

Postby zossy1 » Sat May 03, 2014 11:16 am

Tow bar will fit fine.

User avatar
rossburns
Fast Driver
Posts: 281
Joined: Sun Jun 30, 2013 9:58 pm
Vehicle: NA6
Location: toowoomba

Re: American vs Australian chassis differences

Postby rossburns » Sat May 03, 2014 3:21 pm

no-------don't do it
a tow bar on a MX5---------AAAAAAAAAAAAHHHHHHHHHHH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

User avatar
dmad_dood
Fast Driver
Posts: 275
Joined: Wed Dec 19, 2012 8:16 pm
Vehicle: NA8

Re: American vs Australian chassis differences

Postby dmad_dood » Sat May 03, 2014 5:55 pm

rossburns wrote:no-------don't do it
a tow bar on a MX5---------AAAAAAAAAAAAHHHHHHHHHHH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


maaate. its for a bike rack! Ive got no choice :)

When not in use thou it will be completely hidden and invisible to the eye so no harm.

Tow bar will fit fine.


And cheers, thats what i wanted to hear
Red NA8..

User avatar
davekmoore
Speed Racer
Posts: 4681
Joined: Thu Apr 30, 2009 1:53 am
Vehicle: NC
Location: Esprick, UK

Re: American vs Australian chassis differences

Postby davekmoore » Sat May 03, 2014 10:41 pm

Not true to say towbars don't cause harm. Imagine how carefully the manufacturer designs the front and rear crumple zones to minimise G forces on the occupants in front or rear enders. Then imagine what the designer would say if some random pieces of steel angle bars were added, thus making the rear a non-crumple zone for both cars involved in the bump.
UK since return: Standard NC2 (horrid), C200K, ND2 BBR, NC2 BBR200 (loved it), NC BBR300 (better than BARMY), V-Special, turbo NB8B (my 84th car)

User avatar
dmad_dood
Fast Driver
Posts: 275
Joined: Wed Dec 19, 2012 8:16 pm
Vehicle: NA8

Re: American vs Australian chassis differences

Postby dmad_dood » Sat May 03, 2014 11:12 pm

davekmoore wrote:Not true to say towbars don't cause harm. Imagine how carefully the manufacturer designs the front and rear crumple zones to minimise G forces on the occupants in front or rear enders. Then imagine what the designer would say if some random pieces of steel angle bars were added, thus making the rear a non-crumple zone for both cars involved in the bump.


I fail to see the distinction between adding a tow bar and a strut brace? Albiet the tow bar is bigger and more solid but the same principal would apply to both.

I could argue that the weight penalty of a tow bar is offset by the chassis rigidity increase :P
Red NA8..

User avatar
davekmoore
Speed Racer
Posts: 4681
Joined: Thu Apr 30, 2009 1:53 am
Vehicle: NC
Location: Esprick, UK

Re: American vs Australian chassis differences

Postby davekmoore » Sat May 03, 2014 11:31 pm

dmad_dood wrote:I fail to see the distinction between adding a tow bar and a strut brace?

Agreed
UK since return: Standard NC2 (horrid), C200K, ND2 BBR, NC2 BBR200 (loved it), NC BBR300 (better than BARMY), V-Special, turbo NB8B (my 84th car)

Nevyn72
Speed Racer
Posts: 2189
Joined: Fri Nov 29, 2013 8:51 am
Vehicle: ND - RF
Location: Sydney

Re: American vs Australian chassis differences

Postby Nevyn72 » Sun May 04, 2014 8:36 am

dmad_dood wrote:
davekmoore wrote:Not true to say towbars don't cause harm. Imagine how carefully the manufacturer designs the front and rear crumple zones to minimise G forces on the occupants in front or rear enders. Then imagine what the designer would say if some random pieces of steel angle bars were added, thus making the rear a non-crumple zone for both cars involved in the bump.


I fail to see the distinction between adding a tow bar and a strut brace? Albiet the tow bar is bigger and more solid but the same principal would apply to both.

I could argue that the weight penalty of a tow bar is offset by the chassis rigidity increase :P

Well to play Devil's advocate here for a minute..... :twisted:

Strut tower braces were fitted by the factory in later models (on basically the same chassis) and being a fair way back into the engine bay are not likely to affect the front crumple zone significantly.
Towbars on the other hand are all the way at the back of the car and you would expect they would alter the way the rear bumper crumple zone would behave, especially in the case of a point impact.

Probably the most concerning factor is that the owners manual specifically states the car is not designed to tow and a towbar should not be fitted. This has obvious insurance consequences in the case of an accident......

While I appreciate the frustration with the difficulties of carrying a bicycle, you need to be wary of the potential ramifications of fitting a non-approved structure like a towbar or fixed bicycle rack (like what exocet was designing in another thread) in a worst case scenario.
That being said there's no limit to just what you can carry with an MX5 as this picture demonstrates! :mrgreen:

Image
You do not have the required permissions to view the files attached to this post.
"A Convertible has a top you can put down when the weather's nice...... A Roadster has a top you can put up when the weather's bad."

project.r.racing
Speed Racer
Posts: 3722
Joined: Sun Jan 18, 2009 10:16 pm
Vehicle: Non MX-5
Location: Glasshouse Mountains, QLD

Re: American vs Australian chassis differences

Postby project.r.racing » Sun May 04, 2014 8:42 am

If you want to tow and carry heavy items. Then dont use a sports car. Use a better suited vehicle. You do have a choice.

User avatar
dmad_dood
Fast Driver
Posts: 275
Joined: Wed Dec 19, 2012 8:16 pm
Vehicle: NA8

Re: American vs Australian chassis differences

Postby dmad_dood » Sun May 04, 2014 11:36 am

As far as im aware the na chassis was rated for towing in Australia, only from the nb onwards was there no rating.

If you want to tow and carry heavy items. Then don't use a sports car. Use a better suited vehicle. You do have a choice.


If i was going to be towing a 2 tonne boat or even a box trailer with my 5, then i would agree with you but its a 12kg bicycle which i wouldn't exactly classify as "heavy".
Red NA8..

project.r.racing
Speed Racer
Posts: 3722
Joined: Sun Jan 18, 2009 10:16 pm
Vehicle: Non MX-5
Location: Glasshouse Mountains, QLD

Re: American vs Australian chassis differences

Postby project.r.racing » Sun May 04, 2014 11:49 am

And how much does the rack itself weigh? Plus the weight of the brackets, bar and tounge of the whole tow bar unit? Any of those heavy. I think you'll be heading towards 80kg by the time you have an end result. (Which is really only the weight of a passenger anyway).

User avatar
davekmoore
Speed Racer
Posts: 4681
Joined: Thu Apr 30, 2009 1:53 am
Vehicle: NC
Location: Esprick, UK

Re: American vs Australian chassis differences

Postby davekmoore » Sun May 04, 2014 11:52 am

http://www.usa.dahon.com/mainnav/bikes/ ... lk_s1.html

Fits in MX5 boot with the spare wheel removed, leaving plenty of room for a puncture repair kit. Only weighs 12.5kg. Deduct the weight of the spare and there'll be hardly any weight gain. One of these might be better for the effectiveness of the rear crumple zone than having the spare there.

And I have a hardly used one for sale!
UK since return: Standard NC2 (horrid), C200K, ND2 BBR, NC2 BBR200 (loved it), NC BBR300 (better than BARMY), V-Special, turbo NB8B (my 84th car)

User avatar
dmad_dood
Fast Driver
Posts: 275
Joined: Wed Dec 19, 2012 8:16 pm
Vehicle: NA8

Re: American vs Australian chassis differences

Postby dmad_dood » Sun May 04, 2014 12:51 pm

project.r.racing wrote:And how much does the rack itself weigh? Plus the weight of the brackets, bar and tounge of the whole tow bar unit? Any of those heavy. I think you'll be heading towards 80kg by the time you have an end result. (Which is really only the weight of a passenger anyway).


towbar, hitch, tounge, ball weighs up at 9kg + a bike rack 5k + bike 12.5kg all up 26.5kg. Stuff all. Ive had more weight in the boot several times.

As for the bike..

That thing just looks like an absolute wheelie machine :D
Red NA8..

User avatar
aka_juffa
Racing Driver
Posts: 1005
Joined: Wed Dec 14, 2011 2:40 pm
Vehicle: NA8
Location: SE Melbourne.

Re: American vs Australian chassis differences

Postby aka_juffa » Sun May 04, 2014 6:06 pm

I have rack similar to this one.

http://www.anaconda.com.au/Product/Bike ... k#90026840

Yours for the cost of shipping/postage

J.
Motor Neurone Disease chose me, I choose Voluntary Assisted Dying.

User avatar
Caffeine
Racing Driver
Posts: 1806
Joined: Wed Apr 23, 2003 11:00 am
Vehicle: NB8B
Location: Sydney

Re: American vs Australian chassis differences

Postby Caffeine » Mon May 05, 2014 3:29 pm

My car was the test mule for the Towbars of Woden towbar. I took the tongue off a few years ago when we got our new car (with roof mounted bike racks)

There was a thread on here somewhere. I really should find the pictures and put them online again.

Cost at the time was around $240.
Image
Supreme Blue NB8B, 1:16.98 at Wakefield when stock, but it's not stock any more...


Return to “MX5 Wheels, Suspension, Brakes & Tyres”

Who is online

Users browsing this forum: No registered users and 347 guests