Metric vs Imperial Chassis

[GPBox]

Hi all, can someone clarify the difference between the two ?...are they totally different, which will my 2001 Supersport be ?? ...if I bought a full cage would it have to match ?

 

cheers Graham

[DJ.]

Imperial chassis is phosphor bronze welded and has imperial threads made by Arch.

Metric chassis has Mig (?) welding and metric threads/dimensions I suppose.

 

When advertising roll bars everyone specifies Imperial or Metric, so I'm pretty sure they are different.

 

I'm pretty sure it will be Imperial as I think the metric chassis came in around the time the sigma engine was introduced.

 

However, I'm sure to be corrected when the experts arrive

 

Duncan

 

Edited by - DJ. on 28 May 2011 21:12:30

[The Pikey]

Your 2001 is an imperial chassis and IMO is far better made than a metric one. The metric is mig welded yours is brazed, the imperial one uses imperial fasteners, the metric one uses mostly metric ones. CC reckon the metric one is stiffer but some people are not so sure..

 

Jason

[CharlesElliott]

2001 is an Arch made imperial chassis. The jig used is stamped on the rear bulkhead turret.

[Grubbster]

The metric is different - some of the chassis rails are quite different to the imperial chassis - easier to get the engine in as there are not the same diagonals, but also no washer bottle mount (so it has to be rivetted on to the drivers footwell).

[weeman]

(so it has to be rivetted on to the drivers footwell).

Passenger side I think Steve? as the primaries are on the drivers side on a majority of of metric chassied 7's .

A very quick way to tell an Imperial from a metric chassis is the headlamp bracket mount;

Metric = flimsy tube with a tiny grubbscrew

Imperial= robust clamp with two bolts

 

Be lucky!!

 

Martin

[Archie Procter]

Yes it's an imperial and yes the cage needs to match. The good news is you can use any of the Dedion Roadsport cages (including the Caged ones) up to 2006 model year, which gives you a lot of options. Including the Safety Devices tall cage.

 

The bad news is you're unlikely to have a lowered floor so you've got to watch your head/helmet clearance with a standard height cage.

 

If you're looking at a SLR cage the chassis may well require modifying in a minor way at the front mounting points - I believe it's a simple enough job at Arch Motors though.

[Archie Procter]

PS. I should have said that I shall be gone from here as from tonight (not renewing membership), so if you want chapter and verse on cage history then do a search in "for sale" and "techtalk" and you'll find my various witterings about what cage variants are out there HTH

[GPBox]

thanks for all the replies, very helpful...G

[Grubbster]

Ah yes Weeman it would be passenger side with a Ford engine, the one I saw was one of the few k series engined metric chassis cars