Post race-bingle NC30 rebuild - pic thread

[StrayAlien]

Was the GSXR 1000 shock the same spec as the 600/750?

I am not an expert, but I am pretty sure they are different.

For example, the racetech site says 05-06 1000 shock stock spring rate is 8.1:

http://racetech.com/ProductSearch/2/Suz ... 00/2005-06

whereas the 06-07 750/600 is 9.5:

http://racetech.com/ProductSearch/2/Suz ... 50/2006-07

[StrayAlien]

Sag check time.

Bike off the bench now - it has been a while since it touched the ground!



Recall, this is a K6/7 GSXR600 shock we're looking at. I have made an offering to the old gods in hoping this shock plus HRC linkage will be the business (slurp).

Just to note the starting point setup on the shock (I think these guys have never been touched their whole life) the preload was pretty much in the middle of its range:



With the help of the pit crew (wifey) and some ballast to make up the weight difference ("honey, would you mind coming into the garage to sit on this bike that has no seat and hug a 10kg battery jump box while learning forward like you are racing"... "sure thing" - what a gal).

Here are the numbers (using terms from http://www.gostar-racing.com/club/motor ... set-up.htm):

Rider weight with race gear: circa 85kg.
Static sag: 5mm. (bike sag under own weight)
Rider sag: 31mm. (bike sag from 'unloaded' to having rider on board)

Pretty good actually. I am not an expert on these things but that is in the ballpark I was looking for.

So, I thought I'd see what I had to do to get rider sag to 25mm. The answer is this amount (about 2 turns) of additional preload:



So with 25mm rider sag, the preload is still in the center third of its adjustability range. I think that is good as well.

But unfortunately, it is not all rosey in gixxercity (say that 5 times quickly). The spring fouls the swingarm by a small amount (refer bits of yellow on swimarm):



When I am on the bike and look down I can see that the weight of my lardy arse on the spring gives it a few mm clearance and it does not foul, so that is good.

If the pull-arm (dog bone) was just slightly longer then all would be okay. So, I have a choice - figure out how to make the pull arm slightly longer (with rose joint turn buckles or some such) ... or get a thinner spring.

The adjustable pull arms would certainly be handy as the shock is not adjustable for length and an adjustable pull arm would mean you could play with ride height.

But, for now, I'll start with the thinner spring route. I'll be making phone calls on Monday.

Oh, and my shock preload adjuster is this little beauty I got from Online Racing Spares (ebay store - http://www.ebay.com.au/itm/SHOCK-PRELOA ... 485c6f3b02) for like $15. It is absolutely perfect (I also got a fork seal driver and flywheel puller bolt from them as well):

[RoninZX-10R]

Did you have any luck sourcing a thinner spring?

Was it only touching the swingarm when at fully extention without any weight on the bike? If so I don't think I'd worry all that much (but that's the tight-arse coming out in me!!!)

[StrayAlien]

he heh. Tight arses of the world unite!

It does not foul a great deal, and only really when the shock is topped out. But, I'd prefer it not to - sort of a safety thing as well.

I am picking the shock up today with a 'test' spring on it. Not the real thing (or rate .. or length!), but just a thinner spring that the suspension guys had and have put on the shock with finger-tight preload to see if it solves the fouling. I'll likely do a test fit tonight and get some pics up.

[RoninZX-10R]

When do you think you'll be at a stage where you can test the rebuilt beast? I'm hoping to get in a coupe of trackdays at Broadford before the Hartwell MCC season starts in Feb and I've been keeping my eyes peeled for a GSXR shock. How long did it take for the HRC linkage to arrive from Rick Oliver?

Which suspension mob are you using?

[StrayAlien]

Hopefully, I'll have it all going mid-December for a some shakedowns somewhere (likely Broadford). I'll be trying to get some track time in January as well. Might see you!

Rick had no stock of the linkages so I had two wait a fortnight while they were being made. After he had them made it was straight in the post. All up, it was three weeks I think.

Re suspension guys, Dave out of Krooztune is the man. He *makes* the suspension for the Honda and BMW Australia superbike teams, so he knows his onions.

[mattUKNC]

Well that was a good read for a Thursday morning at work!
Not far to go now...

[StrayAlien]

Thanks matt, some more distractions for you ..

Here is the patient back with the thinner spring on it. It is an ohlins spring from a Ducati Multistrada (they are sprung pretty soft and many ditch the stock 85 for a 100). Anyways, it is not the right length or rate, but it is for a test only. The thing it does have going for it is that it is very thin .. and just, sort of fits on the GSXR shock:



If I were to use a spring like this, some new preload collars would be needed as the spring is too thin for the stock ones. Note how it doesn't fit the spring inner diameter :



Ok. In, and guess what:



.. still some clearance issues. Not as bad though. Some good advice from a friend was to only tighten the shock mounts when the bike was resting on its weight with the shock installed. Guess what .. it 'shortens' the shock:



That is cool. Looks like it fits by a whisker. And as before, with the bike under its own weight there is no clearance issue:



Unfortunately, the original spring didn't come back with the shock so I couldn't put it back back in for some a/b comparisons.

However, to actually use this spring will cost in the order of $300. New spring, machined preload collars, blah de blah. And that is on a punt that the shock will not need re-valving, which would be another $230. Hmmm ....

So, tommy tight-arse here might just get the original spring back on, and despite some small clearance issues on shock top out, "give it a go".

Yes, the shock will top out when it waving in the air under braking, but it is not actually having too much of an effect on handling at that point. Flip-flopping may also top it out, but I'm not that fast presently.

So, I'll stuff the stocker GSXR spring back on and if it causes issues, then maybe I'll solve it with turnbuckle pull arms. That'll likely be cheaper than $300. Let's see.

[StrayAlien]

Oh! Looked what I found on a 100klm "lunch time" trip today?



Me? Compulsive? ... never ....

(not actually fitted yet, but here is the first sniff at it)

Note it is a 2010. Got to be careful, they changed the length for 2012 (I think). 2012 onwards are not the right length for NC30 (I think):



So, I had to go to get the stock spring put back on the GSXR shock (which the guys at Kroozetune didn't charge me for. Thanks lads) and "on the way" I knew where a BMW shock was for sale. It was the same people that sold me NC30 carbs with mismatching float valves and nasty corrosion in the vacuum chambers. He gave me good deal on the shock because of that and they don't normally do BMW .. and they had just this one bike in parts hanging about. Thanks. :-)

I saw it when I was choosing between GSXR shocks and, on advice that the Showa shock would be a better shock than a Sachs unit, I grudgingly passed it over. It is in very good condition. Beautiful in fact. Not a stone chip or mark on it anywhere. Faultless. A bargain.

I have already modified the frame to hold the GSXR shock, so a quick measurement to see if any more hacking was required:



And the BMW ..



Nice, both are 30mm across top mount, so no more metalwork required up there (I understand there will be some grinding off the battery box mount or something, but I can live with that).

Not shown, but both shocks are 315mm in length.

What about outer spring widths? Here is the GSXR at 82.5mm:



And with those set calipers over the BMW unit:



we get some room. The BMW spring outer diameter is 79mm.

High and low speed compression. Cool:



But it is not all great. What gibbon thought this was a good idea for the preload collar:



One ring with a bolt to secure it. So, how do you secure it when the bolt it facing the engine?? .. and what is more .. the screw is not even a normal allen bolt, it is a tiny 'star' headed bolt. Nice one gibbons.

These ribs on the collar are also pretty meagre:



I thought it might difficult to get ahold of them, but luckily, the preload adjustment spanner can get a grip. Excellent:



I'll do a first fitment later tonight or tomorrow.

Continued ...

[mattUKNC]

Cool, I have one of those shocks on route too, but it's the 2013 version...so fingers crossed.