Road spring compatibility

I'm at it again. Sorry. Not sorry. 

I'm struggling to find out what the dimensions are on the gen4 standard road springs front and rear side by each. I'm specifically looking at the HR negative 45mm and if they are compatible with the gen3. As it stands HR don't even recognize that they do springs for.any Suzuki on their website so I can't find measurements there and none of the other manufacturers like monroe list a standard spring dimension. Can someone shed some light please on at least the factory springs. Cheers.

I still have my standard springs in the garage. I can take some measurements if you want?

Please. I would like free length. Wire diameter. Internal coil diameter. Total number of coils. Many thanks for your time.

Front and rear obviously too.

No problem, I'll get on it this evening.

The results are in:

FRONT SPRING
Length = 350mm
Inside Dia = 87mm
Outside Dia = 115mm
Coil Wire Dia = 11mm
No of Coils = 7.5

REAR SPRING
Length = 315mm / 300mm
Inside Dia = 87mm
Outside Dia = 109mm
Coil Wire Dia = 11mmNo of Coils = 7

I wasn't sure on what the international standard of Coil measuring is. So I've added picture's to avoid any confusion 

Apologies if you have already done this, but it's worth checking all 4 springs because, as well as front to rear, there may be differences side to side as on the gen 3.

Yes, I meant to mention I had measured all 4 springs. The fronts were the same, just the rears with a difference in length.

Ok so basically and without having done the actual maths a set of gen4 springs on a gen3 will roughly give you a lift of approximately 15 to 20 mm give or take as the basic dimensions are close enough but you gain thicker wire diameter and more free length. Useful for those looking at something like that. Now in the absence of published details one has to make assumptions about the negative 45mm from HR. Firstly it's safe to say that they will be shorter than the factory springs and probably quite a bit stiffer too. Given that the gen3 is already on shorter and softer springs it might not be a reach to think that the lowering will therefore potentially be closer to 25 to 30mm rather than the negative 45. I'm going to keep looking for some dimensions for the HR springs though because they are not cheap enough for trial and error. Thanks.

Just thrown some numbers into a calculator and the front is 22.2N/mm on the 3 and 27.1N/mm on the 4 so that would confirm a mild lift using gen4 springs on the gen3.

Mathematically the lift is around 33mm with the gen4 springs, so logically the negative 45s should be around negative 15ish?

Morning Lambert,

the TUV certificate looks to have dimensions for those springs
www.h-r.com/bin/28678.pdf

II.1 Technische Beschreibung (Federn) Achse 1 / Axle 1 Achse 2 / Axle 2

Technical description (coil springs) Drahtdurchmesser in mm : 10,5 10,5
Wire diameter in mm

Anzahl der Windungen : 11,0 9,4
Total number of coils

Länge in mm (ungespannt) : 329 285
Untensioned length in mm

Außendurchmesser in mm : 114,5 112
External diameter in mm