R6 or CBR600 shock with RGV swingarm conversion? Options?

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Stink_wheels
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R6 or CBR600 shock with RGV swingarm conversion? Options?

#1 Post by Stink_wheels » Tue Mar 17, 2015 7:54 pm

Hey guys, I've been reading up different threads on the forums about the R6 snd CBR600 rear shocks being used in RZ350's. From what I can gather when the standard RZ swingarm and wheel are used the R6 shock seems to be a bit too soft when trying to adjust the static sag vs the CBR600 shock being too firm?

I've got the RGV swinger and wheel in my RZ, and currently have the standard RGV shock installed as the kit I used provided the spacers for this shock to bolt straight in. With this set up I have waay too much static sag and the ride height at the back is a little too low for my liking as well so ideally I need a shock a little firmer and a little longer. Has anyone used the CBR shock with the RGV swinger etc? Is it an easy bolt in? How did you go with the static sag?

Any better options? Besides the Nitron which is astronomically expensive, especially once the aussie dollar is converted to GBP
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Re: R6 or CBR600 shock with RGV swingarm conversion? Options

#2 Post by JonW » Tue Mar 17, 2015 8:20 pm

Really good question! I also would like to know about this... the other option is to get a spring for the RGV that will work I guess? Ive got my RGV converted RZ stood next to my R6 shocked RZ, and you can really see that the R6 bike is taller and the RGV bike is lower at the rear. If only i had a standard bike to stand next to them to compare LOL!
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Re: R6 or CBR600 shock with RGV swingarm conversion? Options

#3 Post by Stink_wheels » Tue Mar 17, 2015 8:51 pm

True! I did a bit of research regarding a stiffer spring for the RGV shock and all I turned up was a progressive spring available as an upgrade for the standard shock. Unfortunately being progressive they sell it as a "one size fits all" solution which is not available in various spring rates so theres no guarentee it would be any better in the application. Also that won't address the low ride height like a longer shock would.
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Re: R6 or CBR600 shock with RGV swingarm conversion? Options

#4 Post by JonW » Tue Mar 17, 2015 10:39 pm

Thing is... a spring is just a spring... it doesnt know its an RGV or a BMW spring etc. So long as its fits the RGV shock parts and you know what the OEM sizes and rating are then you just work out what you need from that... or at least i think thats how its done, Ive never talked suspension with a pro shop or even with someone who makes springs, worth a few emails tho perhaps?
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Re: R6 or CBR600 shock with RGV swingarm conversion? Options

#5 Post by Stink_wheels » Tue Mar 17, 2015 11:45 pm

Yep, would still prefer a longer (or height adjustable) shock though
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Re: R6 or CBR600 shock with RGV swingarm conversion? Options

#6 Post by RuZty » Wed Mar 18, 2015 7:41 am

Reservoir on R6 shock will hit the RGV arm. CBR600 standard spring is way too stiff for the RZ unless you ride on very good roads all the time.

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Re: R6 or CBR600 shock with RGV swingarm conversion? Options

#7 Post by seahorse » Wed Mar 18, 2015 7:45 am

Did you get new dogbones with the kit ?
As kits I have used for the 2 conversions I have done have dogbones provided and are different length to standard.
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Re: R6 or CBR600 shock with RGV swingarm conversion? Options

#8 Post by JonW » Wed Mar 18, 2015 8:34 am

Thinking about it... the theory with the RGV conversion if you follow the plans or buy a kit is that the geometry should be the same as the RGV, this should mean that the shock would be in the same orientation and use the same inputs as it does on the RGV. So apart from the extra weight of the RZ (not that much) really these shocks should cope... so maybe this is a shock issue Stinky?
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Re: R6 or CBR600 shock with RGV swingarm conversion? Options

#9 Post by RuZty » Thu Mar 19, 2015 7:29 am

I bought a Penske on Ebay that had a leak but was the right length and end configuration. It was from a VFR400 and had a 1000# spring and cost me around $200. I sent it to Penske to be rebuilt, revalved and resprung for an RGV250 with my weight plus the difference between the RZ and RGV, which cost another $200. I found the rear sat too low with the links made as recommended and had to shorten them about 10mm.

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Re: R6 or CBR600 shock with RGV swingarm conversion? Options

#10 Post by mike YPVS » Fri Mar 20, 2015 6:49 pm

Hi, a lot of you guys know I had "soft spring" problems a while ago!

The suspension expert I went to told me that you can change springs for any shock BUT you have to keep within limits and not to stray too far from the standard spring supplied with the shock.

He explained that "IF" you could get a much stronger spring to fit it would "overpower" the shock internals. He explained that this is the reason that spring suppliers only usually go a little harder or a little softer than standard.

He told me that "IF" I could get the spring weight that I had worked out that I needed to fit my R6 shock the whole shock would need to be rebuilt and reset internally or the stiff spring would overpower the internal damping and it would react too quickly and bugger up the damping altogether.

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Re: R6 or CBR600 shock with RGV swingarm conversion? Options

#11 Post by Stink_wheels » Wed Mar 25, 2015 4:59 am

mike YPVS wrote:Hi, a lot of you guys know I had "soft spring" problems a while ago!

The suspension expert I went to told me that you can change springs for any shock BUT you have to keep within limits and not to stray too far from the standard spring supplied with the shock.

He explained that "IF" you could get a much stronger spring to fit it would "overpower" the shock internals. He explained that this is the reason that spring suppliers only usually go a little harder or a little softer than standard.

He told me that "IF" I could get the spring weight that I had worked out that I needed to fit my R6 shock the whole shock would need to be rebuilt and reset internally or the stiff spring would overpower the internal damping and it would react too quickly and bugger up the damping altogether.
Yep, you are spot on!! Aside from the spring issues I don't want to persist with the RGV shock regardless as it is too short for my preference.

JonW, I used the NK Racing kit so the geometry is "spot on" to an RGV but what works on one bike doesn't necessarily work on another, also what works for one rider also doesn't necessarily work for another! I'm leaning towards grabbing a CBR shock to try seeing as not much else has come up (other than a custom spec heavier Nitron shock). I'm curious to see how it will go with the RGV swinger etc, compared to the common complaint of being too firm for the standard RZ. I've got a Daytona 675 that I ride on the road and track so firm suspension is something I'm quite used to haha...
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Re: R6 or CBR600 shock with RGV swingarm conversion? Options

#12 Post by MK » Thu Mar 26, 2015 3:26 pm

I heard the RGV guys often use GSXR 600 shocks as a cheap improvement, but don't ask me what year.
What I saw is that some of them have an external reservoir that would need a bit of frame rework / that may hit the swingarm.

I have 2 RZ's with RGV swingers and use Technoflex shocks in both.
They're a bit pricy, but excellent pieces of hardware.
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~2q1

#13 Post by subxero » Sat Apr 04, 2015 10:22 pm

since the rgv conversion uses the rgv linkage knuckle which requires the shock to have the U bracket at the bottom of the shock for it to bolt up to the linkage as the U goes around the knuckle pivot which contains the bearings and race there are a few modern bikes that have shocks with such a bracket but the trick is finding one with a remote reservoir.

Some of the 90's error gsxr's have such a shock that will be close to the correct length. Remote reservoir with compression i believe and rebound on the shock. Modern GSXR shocks would work. 04 - 09 600 or 750's have a good length and the right brackets but have piggy back reservoir that would interfere with the RZ shock frame mounting bracket. The springs are stiff but you can find a spring off something else to swap on to lighten it up. I think the 03 gsxr 1000 has the same size spring but in the 8.... kg/mm range as opposed to the 9.5kg/mm range of the 600/750's mentioned earlier. I would have to look up years to be 100% certain on that. 08 Ninja250 through modern ninja 300 shocks would swap on with out much trouble but they have no adjustment other than preload. That being said they would probably be a step up over stock rz shock. The ninja shocks will be slightly longer than stock but you can make that up in the bones most likely with out changing the linkage geometry to much. You can always look at aftermarket options for the ninja 250's as well, elka, penski Ohlins have various shocks with various ranges of adjustment some at decent prices that have remote reservoir that might swap onto rz350. I plan on looking into this a bit as used aftermarket shocks for these little ninjas pop up on ebay from time to time for decent prices + the spring rate for these shocks should be close to what is needed for the light rz350.

I figure i will snag a stock ninja 250 shock for next to free just to check mounting and changes to ride height clearance issues with the swing arm ect... and then go from there

time will tell.

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Re: ~2q1

#14 Post by Stink_wheels » Sun Apr 05, 2015 3:47 am

subxero wrote:since the rgv conversion uses the rgv linkage knuckle which requires the shock to have the U bracket at the bottom of the shock for it to bolt up to the linkage as the U goes around the knuckle pivot which contains the bearings and race there are a few modern bikes that have shocks with such a bracket but the trick is finding one with a remote reservoir.

Some of the 90's error gsxr's have such a shock that will be close to the correct length. Remote reservoir with compression i believe and rebound on the shock. Modern GSXR shocks would work. 04 - 09 600 or 750's have a good length and the right brackets but have piggy back reservoir that would interfere with the RZ shock frame mounting bracket. The springs are stiff but you can find a spring off something else to swap on to lighten it up. I think the 03 gsxr 1000 has the same size spring but in the 8.... kg/mm range as opposed to the 9.5kg/mm range of the 600/750's mentioned earlier. I would have to look up years to be 100% certain on that. 08 Ninja250 through modern ninja 300 shocks would swap on with out much trouble but they have no adjustment other than preload. That being said they would probably be a step up over stock rz shock. The ninja shocks will be slightly longer than stock but you can make that up in the bones most likely with out changing the linkage geometry to much. You can always look at aftermarket options for the ninja 250's as well, elka, penski Ohlins have various shocks with various ranges of adjustment some at decent prices that have remote reservoir that might swap onto rz350. I plan on looking into this a bit as used aftermarket shocks for these little ninjas pop up on ebay from time to time for decent prices + the spring rate for these shocks should be close to what is needed for the light rz350.

I figure i will snag a stock ninja 250 shock for next to free just to check mounting and changes to ride height clearance issues with the swing arm ect... and then go from there

time will tell.
Great post, cheers
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Re: R6 or CBR600 shock with RGV swingarm conversion? Options

#15 Post by subxero » Sun Apr 05, 2015 9:36 am

forgot to mention 2 things, 1, the valving for these aftermarket small displacement ninja bikes is probably pretty close to correct for the RZ as well. And 2, i think the small ninjas 08 - current use 12mm bolts for the shock joints. Not sure what the rgv calls for, probably 10mm i can do a quick look later today.

minor hiccup at best if they are not the same

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