Question about rear shock swap.

Can I use a CBR600F4 rear shock? I see a lot of talk about the F4i rear shock but I can't find any suitably stiff springs so I want to use an F4 shock and put a 17kg/mm spring on it. Apart from shimming to get the right height this is a no mod required swap right?

I did search but wanted to be absolutely sure before I buy.

 

Daugherty Motorsports offers a modified F4 shock so I would have to say yes it will work. From Jamie's web site here's what he has to say about the F4 shock.

"Another DMr exclusive is the CBR600F4 shock for the 6th Generation VFR. The standard CBR600F4 shock has a new spring installed and fully revalved with the same high-performing DMr valving system. A modified upper mount is included which allows the CBR shock to work on the VFR. The price includes the donor CBR shock so nothing would need to be provided by the customer."

Personally I would also change the damping along with any spring rate change as these two forces work hand in hand. I actually bought an OEM ABS VFR shock and sent it in to Jamie to have it modified to work with my weight and riding type I would be doing, so far it's been one of the best investments I made.

Cheers.

 

I know I should, you know I should, but I just want to avoid spending $400 on a rear shock. My old SV650 spoiled me, I swapped the rear shock with a used zx10r shock that cost $70 and it was instantly trackable and I am trying to achieve the same level of budget amazingness here. If it is absolutely a waste of money to buy a used F4 shock and a new spring do tell me now but if it will be pretty good I am just gonna go with it.

 

I think the benefit of using a zx10 shock on a SV650 is that the zx weighs more than a sv and therefore the damping would be different and more suited for track riding as well, where as the F4 weighs less than a VFR and would be under "damped", I could be off on this but that is my take. Of course it may work well enough for you. That being said, I think the total cost for my shock upgrade was $295 (Jamie's work) + $40 for the shock (off eBay). Worse case scenario, it doesn't work for you and you can always put the stock shock back on until funding becomes more available for updating the F4 shock. Good luck.

EDIT: Correction, the shock was $65, I forgot I was outbid!

 

Well the ole tax return was nicer than I expected so just going straight DMr but I had another question.

How much can I safely raise the rear without making the bike unstable?

I was thinking 1 inch would be fine since the geometry of the bike is fairly relaxed to begin with but I may be completely wrong. I really want to wake this bike up but I can't find much info on this here, either no one does it or I just can't find it...

 

It's actually more common with the 5 Gen, but I don't recall the actual raise in height most do. You can ask Jamie and maybe he can add a spacer to the top shock mount to get you what you need. He should also know how much is too much.

 

I did ask him but I always get multiple sources before deciding.