Post race-bingle NC30 rebuild - pic thread

[RoninZX-10R]

I'm guessing the engine ran for a little while after you binned it coming out of turn 1? That's the only problem with running an open carb set-up, everything gets sucked straight down into the engine. I got annoyed with having to clean out the carbs after every race weekend so I'm trialling a very expensive filtering system to should stop all dirt/grass/crap going in...a bit of aluminium mesh (bought from Supercheap Auto) bolted to the top of the carbies with a stocking stretched over the top acting as a filter. I haven't trialled it yet, but I'm hoping it doesn't restrict air flow, otherwise the missus will crack it that I've wasted a pair of her stockings for nothing

[StrayAlien]

he heh. Yep. I have considered doing the same. Open carbs are all okay as long as you dont trash it in mud!

[StrayAlien]

Well, guess what arrived yesterday. Hmmm ... mysterious eh ...



russle russle .. unwrap ...



Bingo ... a Rick Oliver HRC replica linkage!



You'll need to sell your grandmother .. again, but I have a feeling it'll be worth it. Maybe.

Now, this kind of screws with my pic chronology but I thought as I'll be doing work on this in the next few days so I'll get some pics in.

So, if you are like me, and just love this stuff, then you'll agree this baby is a work of art.



Comes with bearings installed.

It is clearly very different to the stocker. They have three holes and the widths are the same, but everything else is entirely different:









Having gone over my crash many times, I know, in the end it comes down to me, my throttle hand, and how I ride the bike. It was my mistake. That is a simple fact.

However, lessons learned, the bike tells you things. And you have to be able to listen and even if you do not understand, try to change things, seek advice, and gain experience and knowledge to help you understand better.

Certainly, on that day, the bike was telling me that my suspension was just wrong - plain wrong in almost every way.

I had borrowed a friend's modified-for-nc30 2006 gsxr-750 shock and it was great. It had been built up by the current owner/suspension guy of the Honda Australia superbike team, Paul Free of Motologic, and it was great.

I had to give it back again, put my old stocker on and it was a pogo stick in comparison. Even with almost fully-in rebound.

I didn't even finish qualifying that day - the bike was bouncing around so badly I had to come in and make some adjustments to see if I could settle it down.

It did, a little, but I still went at it and crashed. Lesson learned!

But, there is NO WAY I am getting back out there without getting the suspension sorted. The front was terrible, and I have the feeling that rear shock has had no attention in more than 10 years.

[StrayAlien]

Boring textual rant:

Disclaimer: I am not an expert on suspension, but here is my take:

The thing about the stock NC30/NC35 linkage is that is *very* progressive - meaning that as the rear suspension compresses it gets harder and harder to compress. So, if you want firm (race) suspension, when you are at lean and the suspension is well compressed it can be very hard indeed, taking a lot of force to move it a little, resulting in a loss of traction and a loss of confidence. It means you suspension operates quite differently when compressed.

I had a chance meeting with suspension guru Dave Moss (two times US 450cc champion - on a NC30) and he has his rear spring at a "minimum of a 1200"! (that is a '22'). Now think about that - I think that might be the sort of spring you would use to hold up a goddam truck! .. this guy wins races but must be very good at sliding and holding his teeth in at the same time. It is a compromise.

By comparison, Nitron, for their 'race setup' will ship (circa) an 850 spring (a '16'). Which is still pretty darn stiff.

These spring rates (I guess) might be terrific for stuffing your tyre into the tarmac for heat but they ain't great at lean.

Go and read some threads on this forum about replacing the NC30 OEM shock with another, like a BMW 1000RR - they say the same thing - it'll likely be too soft on the OEM spring and you will likely need to revalve it to get serious proper operation. Why? The very-progressive rear linkage.

So, why the HRC linkage then?

The HRC linkage is much less progressive. The HRC linkages make the rear suspension more linear (equals less progress). It is not linear, just far less progressive.

Is it odd that most modern sportsbikes have *much* less progressive suspension than the NC30? No. It would surprise me if anybody is producing a serious sportsbike these days with mega progressive rear suspension.

But, here is a cool thing, with an HRC linkage, your choice of replacement rear shock is made greater. There are many more OEM rear shocks that are a lot softer than the NC30 OEM that could well do the job with the HRC linkage that simply could not with the OEM linkage (and no, I am not selling HRC linkages).

An no, I have not yet ridden with an HRC linkage, but the theory is pretty sound I think. You can be sure when I get it out there I be reporting back here.

So, what shock then? Nitron? No way. I've not had any good experiences with them. AFAIK, they had never done a shock setup for an HRC linkage and based on an email discussion with a friend of mine took his suggestions as their NC30 HRC setup. Another friend of mine has had his Nitron rear redone twice now... no way.

And there has been a lot of noise about the BMW shock recently, but my starting choice is not that.

..... continued

[Drunkn Munky]

Nice linkage I haven't done any proper testing with mine but i can confirm my bike handles very well with it fitted, what shock are you going to use?

[StrayAlien]

Man oh man you are quick!! Stay tuned for the full story on the shock .. in about 5 mins ...

[StrayAlien]

Here is the candidate:



It is a 2006 CBR1000RR fireblade shock. I got it for free. :-) Quick shameless plug: Thank you Ian Rider of Rider Brothers training VIC - he was happy to get it out of his shed and I was waaaay more happy to get it into mine! If you've not done their 'Knee Down' course - you are missing out. I never had my knee down before the course - simple afterwards. Nice one Ian.

Ahem: back on track. Check it out in comparison to the OEM:



If you look at my OEM you'll see it has had every extra mm of height sucked out of it. See the eccentric at the top? This gave about 4mm extra height over stock. What an effort!

The 2006 CBR shock is 213mm in length. That is the north end of the HRC spec for rear shock length but better than the south end. :-)

All bolts fit and it does go in. So from this:



to this:



Note this is an initial fitment without the HRC linkage. I was just stuffing around with 'would it fit?'.

The first experiment was with my shortened pull-arm ('dog-bone') that had been welded up and moved (I think) 8mm in - to raise the height. This guy:



I undertand this is a common mod to get more rear end height. But .. the shock spring fouled against the swingarm:



Fitting a standard NC30 pull arm got it okay again:



Looks good:



But ... (and there is always a 'but' or two):

Compression adjustment is obscured a little:



and probably more important to most people out there is that you'll need to build yourself a new battery box. I have a RO race subframe but I imagine it is the same for EOM subframes. The gas reservoir sticks into the space where the battery would normally be - so that has to be moved back a bit:



I'll be building that with my 'tinsnip enginering' skills and posting it here. Wish me luck.

The shock also has the older 'ramp' type preload adjustment, which seems pretty out of date, but I'll give that a go. Ideally, I like to pick up a remote preload adjuster for it somewhere. For now, this is 'experimental science'.

So, besides being the right length and actually fitting the damn bike, why specifically the 2006 CBR shock then?

Continued ....

[StrayAlien]

yes, why specifically the 2006 CBR1000 shock? Quite down at the back now.

Well, a bit of science and a bit of a hunch .. and a hint or two from someone who owns the 2006 CBR1000 that came 2nd in the Australian Superbike Championship (ASBK) for that same year, and also owns an NC30 with a HRC linkage.

For the 2006 1000 Fireblade road model Honda changed the rear linkage and softened the rear shock spring to suit. Find an online review and you see they made the rear end less progressive. It already was not-very-progressive but this is a bike made to win races so they made it even more linear.

Here is the thing. As I understand it, the 2006 model road bike linkage is not too different from the 2005 HRC race linkage. Could be hear-say, but I have it on pretty good authority.

And here is the cool thing. That 2006 linkage (or 2005 HRC linkage) is almost exactly the same as the NC30 HRC linkage. Aforementioned owner of CBR1000 (and also a NC30 with HRC linkage) has graphed them and they are pretty darn close.

So, it it highly likely that the 2006 shock will suit the NC30 HRC linkage very well. The shock has come off a bike that has a linkage very similar to the NC30 HRC one. 2006 spring is about 650 ( or '11.5' - compare with Nitron or Dave Moss comments above) which is about where friend has his shock on his HRC linkage NC30 .. and he is *fast*. I mean really fast ....

Could all be complete crap, but I doubt it very much.

So, let's see how we go. I will report back here in full when back on track with suspension dialed in.

[CMSMJ1]

This is a great thread.

Keep your thoughts a rolling into it mate.

[Drunkn Munky]

Yes great reading keep it coming. Before I got my linkage I did a bit of research and pretty much come
to the same conclusions that you have although I have gone for a softer spring. I did try a 600lbs spring first and found it miles to hard, im now running a 500lbs spring which I feel is perfect but I am only around 75kg kitted up.