Shock Option... Vfr1200 Rear Shock On Vfr800?

Hi,
Just a new way to rear shock option... is the shock of a vfr1200 can fit on a vfr800 6th generation?

Not sure, by looking at pictures it very well may, but looks kinda short too. Either way, I think its probably a bit early to be sourcing those for cheap, which is usually the benefit of swapping to another OE shock. Pick yourself up a cheap CBR shock, proven winner for the budget minded enthusiast.

Well, let me put it this way.

I have a 6 th gen ohlins shock on my 5th gen, fit fine with a bit of shimming.

Miguel is running his old ohlins 5th gen shock on his new 1200.

So I'm gonna say it'll fit, the only question is length and how that effects ride height.

Vfr1200 shock length is 321.5mm

5th gen shock is 326mm

6th gen shock is 317mm

Then there is the spring rate. I ASSume the 1200 has a heavier spring, being a larger/heavier bike but that depends on the linkage leverage ratio.

So putting a 1200 shock on a VTEC should get you about 10mm more rear ride height.

To save from starting a new thread about this; since I have a 2005 VFR, and I weigh about 280 (thank God I am tall) which year/model CBR would be recommended? Also, how do I determine which springs front and rear I should use?

Thanks.

To save from starting a new thread about this; since I have a 2005 VFR, and I weigh about 280 (thank God I am tall) which year/model CBR would be recommended? Also, how do I determine which springs front and rear I should use?

Thanks.

At 280 you'll need at least a 24kg (1350-1400lb) rear and 1.1kg front spring.
I would suggest an CBR F4i shock that has a remote reservoir for 6th gen use. Others have used a CBR 929 shock on a vtec, but you basically have it's fixed reservoir sitting on the head/headers which is a Bad thing.
That big a spring change will no doubt over power the shock stock damping so a re-valve would be required.
I personally would hut down a used Ohlins or Penske before spending hundreds to revalve/rebuild a stock shock. :ph34r:

BR

So putting a 1200 shock on a VTEC should get you about 10mm more rear ride height.

It's actually over 20mm, which is too much from my experience. The 6th Gen shock is 315mm eye-eye, so that's a difference of almost 7mm. A shock length of +3mm is ideal if you have a sstock front end geometry.

OK, earlier, I was guessing on the linkage ratio without looking it up.

So,

If a 7mm longer shock gave you over 20mm more rear ride height, that would mean the linkage ratio is more like 3:1

Which seems wierd, given that the 6th gen shock has a 53.5mm stroke, and 120mm of rear travel, which equates to a linkage ratio of 2.24:1

so 7mm x 2.24 = 15.7mm additional rear ride height.

[image: Posted Image]

It is closer to 4:1, actually. The 6th gen shock does not have anything near 53.5mm of stroke, you must have looked up some Ohlins info. I'm not sure where their travel numbers come from, myself and others think it must be the mechanical travel if the bottom out bumper was not there. That is very much a nonsense travel number, the actual travel of the VFR800 shock is 25mm.

I agree with Jamie lengthing my Ohlins by 1 turn of the eye dropped the rear wheel 4mm.  My uderstanding is that the thread pitch on the Ohlins shock eye is 1mm.

Cheers

Phil