Shock replacement

[zeke]

Hi all, have just aquired and fitted a 2007 CBR1000rr Showa to the NC30. Both ends bolt straight in, with a 70mm hole saw dealing to the battery box to accomodate the gas canister. Has any one else tried this? First impressions look good, with the length being about 10mm over standard. On max preload (seemed a bit soft at lower settings) This has lifted the rear 20mm static, and about 10mm with a 95kg lump on top. Feels very compliant in first part of travel, and have set compression damping 3 clicks off hard. Any advice appreciated, and will let you know how it goes after next meeting.Cheers

[StrayAlien]

Hi zeke,

Warning: I am no expert ..... but I am learning ... so here is what I know so far ...

Is it a race bike?

Spring conversion chart for imperial: http://www.hraefn.net/projects/spring_rates.php

I have a 2006 CBR1000 to try the same thing with but using a VFR400 HRC linkage. At 313mm these shocks long they are in the ballpark for the right length, and yes, they bolt on - with a change in battery box.

It seems the 2006-2007 CBR1000s came with a softer spring 11.5 down from 12.0 and with a slightly less progressive rear linkage.

The 11.5 thing is sort of in the ballpark for 400 HRC linkage, but, as I understand it, would be somewhat compromised with a standard linkage (VFR & RVF).

For example. If you go an buy a Nitron *race* shock for the standard linkage it'll come with a 16.

I bumped into Dave Moss recently (two times US 450cc champion - on a VFR400) at the track and he was *amazed* they were giving me a spring "so soft". On his race bike he runs (wait for it ... ) 25!!! .. and says the minimum starting point was a 21. Whaaaaat!!!! And this is a guy that makes his living from suspension and bike setup and is a champion. Merciful mother ...

So, it might work, I guess your backside is the real judge, but from the info I get, on a race bike with the standard linkage it might not be that great.

But, I'll likely end up using a modified 2005 GSXR 750 shock - no so much cutting and hacking and you get hi/low speed compression plus the preload adj is a collar, not a stepped jobby and it is also at the top so it is nice and easy to get at. :-)

But ... like I said, I am no expert and I am going to try it also, but on the HRC linkage.

[Drunkn Munky]

As above really, as it is the CBR1000rr shock will be way too soft if using the stock NC linkage so you have 2 options,

1, revalve and respring to suit the NC linkage
2, fit the HRC linkage and maybe the spring to suit your weight but not as drastic spring change as above so no revalving needed.

[zeke]

Thanks for the feedback, yes it is a race bike only, and the seat of the pants say it will be a bit soft. We have the origonal Showa with remote resevoir, which has been revalved and works ok, but the higher ride height was what we hoped for. Just a dumb question on the HRC link, was it just the link bar that was shorter, or is the triangular progressive set up different as well? We have a couple of rough modified links at shorter lengths which will have to be braced before I would trust them: does this effect the spring rate much? One is 110mm and another at 102. Cheers

[Drunkn Munky]

The HRC pull arm is actually longer than the NC arm not shorter and yes the triangular link is also different.

See here for my comparison to the NC35 linkage
viewtopic.php?f=62&t=37454&start=30

[krisztian_andre]

How does the HRC link affect the ride height?

[Drunkn Munky]

It doesnt, the length of your shock will.