Traxxion Dynamics' Linear Rate Springs - GSXR1000

Curing the K6 thou's bumpy bits.
Previous posts dealt with the suspension upgrades on the trusty '06 Gixer. The shock was re-shimmed, serviced and fitted with a linear rate spring. No problems there (with my limited ability at least). The 43mm Kayabas were re-shimmed and filled with fresh oil but, due to funding, came back with the standard 0.95kg progressive springs.
As the months progressed, they started to leak oil and preload adjusters were screwed right in to try and prevent bottoming out. The front was getting very harsh to say the least. Put up against modern bikes and she was beginning to show her age. Smooth roads were fine, but the bumpy stuff was iffy, sometimes scary.

SO...
A couple of emails to Traxxion Dynamics and they sorted me out with their straight-rate springs with an overall rating of 0.975kg. I just had to choose the fitting method for the type of spring - either cut the spacer, or alter the top-out springs within the cartridge. I decided to leave the cartridges alone and just cut the spacer.

Forks were stripped as per, leaving cartridges in place, then the old seals were taken out and plenty of brake cleaner inside the outer fork tubes to remove the dirty residue. Photos are limited unfortunately - I got carried away with the job and forgot to take enough of them!

Spring compressed ready for the fork top to be removed from the damper rod assembly.

New springs, note the extra length.

Traxxion provide all the instructions on how to measure the amount to be cut away, but they'd already given me the nod that 40mm was the way forward for the Gixer. The picture below shows the 40mm cut off the spacer (left), and new holes drilled in what's left for the spring compressor.

With new oil seals fitted, it was time to refill with oil and put them both back together. I'm running with the Suzuki standard air gap of 101mm. 
(Both forks were leaking, and when I stripped them they had an air gap of 140mm - no wonder they were getting harsh!)
I slipped the forks back into the clamps and refitted the mudguard, wheel and calipers. I only tighten the lower triple clamp bolts once the wheel is in and the suspension bounced up and down a few times. This relieves any tension/twist when fitting the wheel etc. 

Road test time.
I think we're onto something here. I basically just set my compression damping at ten clicks out, rebound at seven clicks and the preload to the first line on the adjusters. 

A blast along some of my favourite roads and I've still got an inch of travel in reserve! What a difference. It feels so much more stable in the bends now which could be as much do with oil level as well as the different geometry. I'll experiment with less compression damping to see if I can get a softer/more plush ride next.

Overall, I'm happy as. No leaks (for now), and the bike's actually easier to ride. A highly recommended mod. If you're not using a zip tie on your stanchions, go get one now. That little plastic tie is a mine of information!

Suspension Upgrades: Does A Six-Year Old Bike Still Cut It?

Can your bike's suspension be upgraded to match the latest technology?


This isn't about using professional racers to test on a short circuit track because that would mean nothing to the average road rider - like me. I want to hear in layman's terms if spending $500 - $1000 on your standard bike's suspension is a waste of money, or the best thing you could've done to improve it. We're the ones out there buying and riding the bikes, and most of us on the public roads only; so, can a basic upgrade to your favourite toy make it a match for the latest kit?


Let's find out.

• The bike: 2006 GSXR1000K6 
• The roads: A mix of fast, bumpy sweepers and the tightest of hairpins.
• The question: Can the oldie hold its own against a newbie?

2006 GSXR1000 K6

Pointless?

Not for the majority of riders who have to battle on with their existing bikes because a new bike is out of their price range. And maybe the riders who think that the suspension must be effective just because it's fitted with Up Side Down forks and a monoshock.

I wanted to know for sure if what I'd heard is true. That spending money on suspension is the best use of readies that a person can throw at their bike. 
Or should you just get a race can? At least it'll sound fast when everyone's on your ass trying to overtake you!

150BHP? That's about 100 more than you need for the road!
That's what I was told by Peter Clements of ProMechA. And I know he's right, strictly speaking, but when did that ever matter?
But to be fair, this guy is very switched on and tells it like it is. When you can get hold of him on the phone, you're in for a great conversation. I had an idea on what the GSXR needed - I just needed to relay it to Peter. It's simple, I wanted the bike to be plush on bumpy roads (after all, it's quite stiff as standard), but have the ability to handle high speeds too but, on top of all that, be capable of destroying anyone else on a track day (should I partake in one)!
Should be easy, just a bit of spring manipulation - or so I thought.


"You can't have it all," says Peter. "What are you going to be using it for? Track days, or the road?"


"Hmm, road work I guess."


"OK, well I can't give you a sports-tourer and a race bike all in one. You need to choose what sort of bike you want." 


And that's when it hit home. There is no best of both worlds, no adaptive suspension that works for every road or track. And that's the first thing you need to understand. 
I've watched videos, read everything i can find on the internet and bought books on the subject of tuning suspension, but until you realise there isn't a perfect fix for every road surface or track, you're bollocksed. 

20km/h? You can do better than that!

And don't forget, your suspension needs to be serviced too. 
Oil deteriorates with use, gets contaminated with metal (from the springs/sliding surfaces) and needs to be flushed out and renewed at regular intervals. 
If, like my GSXR, your bike is well overdue for fresh oil, have the shock and forks serviced before adjusting any of the preloads or clickers. Any adjustments made before this will just not be as effective and will probably put you off the learning process.
It may be daunting to start playing around with the settings initially, but once you get into the spirit of adjusting things, it starts to become clearer and, the more you play, the more you learn. Just remember to write down your original settings so you can always go back to your start point if need be.


OK, forks and shock serviced, correct weight springs fitted. What now?
Peter has a stack of information on his website covering a good variety of bikes. For me he advised a complete service and re-valve (compression/rebound pistons and shims), a linear rate spring and an anti-squat valve for the shock, and a service and re-valve on the forks retaining original springs (standard being near enough for my weight).
Although you can strip the forks yourself at home, would you know how much porting or changes in shim arrangement are required? A suspension pro will have a fair idea on what works for the chosen conditions which is going to save you time and money in the long run. These are the guys that have put in the hard hours already.


Anyway, let's get on with it. First run out, and I had a play with the rear shock. Leaving the forks at Peter's recommended starting point, I adjusted the sag on the rear and then played with the compression and rebound adjusters. This also involved a quick run with them fully unscrewed, which was against Peter's advice I might add, just to feel the difference.

This caused the Gixer to tie itself in knots coming out of bends hard! 

It wallowed and weaved its way all over the shop so probably not the best testing method, but then it's good to feel the difference:) I'm now at a base/standard setting and it's working quite well.

With only a few weeks on it, the "ripping" effect I had on the rear tyre is starting to clear up with the shock working correctly, but there is evidence of a rebound issue (uneven tread wear pattern). Hopefully fine tuning will cure this, but my idea of fast road work probably isn't the same as a genuine fast rider's - which is what it's valved for. Oops.
The forks are still harsh on most of the low-speed local roads, but then it always was. However, the faster you're prepared to push, the better it gets - is this a good thing? Probably. If the bike is safer and more capable at speed, when there's more chance of mistakes, less time to react and the unknown is lurking around every bend, this can only be a good thing.

Smooth roads, happy days.

This is a learning curve.
What I thought I wanted, and asked for, probably isn't what I actually needed. Having ridden a mate's 2006 CBR600RR, I knew how plush a sportbike's suspension could be on slow, bumpy roads. But until I actually tried pushing down on the front end of the CBR at standstill, I'd never have realised how soft they were as standard! It's like a trail bike, due to its progressive springs, where the GSXR is rock solid all the way through. 
No wonder you meet the nicest people on a Honda.
I wanted something to soak up the slow, bumpy roads and then perform well at high speed, but it's impossible - you have to decide where your trade-off is. 


Forget the bragging rights, ask yourself this question:
How often do you exploit the top speed of your bike? 
Honestly? Not very often.
As a quick comparison, I took the DRZ out for a quick spin in some notoriously tight, uneven bends. The supermoto flies round bumpy, 60-80km/h corners without a flinch whereas the Gixer, although holding its own while you bounce out of the seat, makes you work harder for it. 


Conclusion
I can see why the softer, streetfighter-styled factory bikes are so popular nowadays. Easily as fast in the real world, but with the added comfort to protect you from all the jarring and hits you take from the average, poor road surface.


I guess I ended up with a fast road bike that spends most of its life at slow speeds. In respect of whether this bike can hold its own against a new one, no problem at all, but is that due to the rider, the components, or the fact that superbikes haven't really moved that far forward in the last six years? 
A smidgen of all those I guess, but I will say this for the GSXR, now when you crack it open to make rapid progress, the world underneath it just smoothes right on out. 


ProMechA
If you're looking to upgrade the bouncy bits on your bike, give Peter a call on 03 9574 1164 and let him explain what does what, and why. He'll tell you exactly what's needed to turn your bike into the bike you actually want - and that's far more important than turning it into something you don't need!

GSXR1000 K5/K6 Suspension - The Forks

This is where the fun started.

All I wanted to do was chuck another couple of seals in (not that they were leaking), and change the oil. A cartridge revalve, and maybe even a spring change would have been nice, but costs needed to be kept down so I decided to keep it basic.

Some form of spring compressor is needed to disassemble them properly so it was out with the welder to knock up a quick tool. It ain't pretty, but it works. The bolts, filed down to 8mm on the ends, screw into locating holes on the plastic tube above the fork spring allowing you to push down and compress the spring to allow access to the locking nut below the fork top. 

At least that's the idea. It's useful if you're generously proportioned too because those springs take some compressing! In the end I reverted to two ratchet straps around the tool and then around the wheel spindle reinserted in the bottom of the fork leg. This works a treat, but it's still a two man job.

The following picture will give you an idea of the assembled unit within the fork leg itself. This is what you'll get if you just remove the 8mm Allen bolt from the bottom of the fork leg instead of removing spring first. You can see the cartridge, the spring, the plastic tube and the fork top nut complete with rebound and preload adjuster.

Unfortunately, once engrossed in the forks, the pics stopped, but here's a brief description of reassembly. 

I'd already bought new fork seals off eBay (43x55x9.5/10.5), but as Davey always says "The poor man pays twice" and, sure enough, they were useless... but I was yet to find that out. 

So, cartridge refitted (spring must be removed beforehand), fork tubes together and now we just needed to fill with oil and bleed the damper assembly. This involves filling the fork with the correct grade of oil - don't just risk a "5W" hydraulic oil, this was also my undoing... but I was yet to find this out too. Buy a well known, or recommended, fork oil from a motorcycle dealer because every make of oil and grade has a different viscosity even if it says 5W on the bottle. Another lesson learned.

Around 600ml of oil is poured in, and then you can bleed the damper. The damper rod must be pulled up and pushed back down several times steadily until the resistance is the same all the way through the stroke. There are fork bleed tools you can buy to make this easy. My advice is to leave the fork for ten minutes at this point and then retry to allow any bubbles/cavitation to disperse. 

Now you can set your fork oil height. Check manufacturers recommended heights and ensure the outer leg is as far down as possible. Hold the fork upright and check how far down the oil is. A plastic tube zip tied to a piece of welding rod and a syringe is the ideal way to remove the right amount of oil. Just mark the welding rod at the right height, insert it into the fork leg and suck out excess oil. All good? Cool, time for the spring.

Refit spring, washer and plastic tube. Compress spring, pull damper rod back up through (another piece of welding wire) and fit the special plate (in the pic) above the spring and under the locking nut to hold down the spring while you refit the fork top nut (don't forget to refit the rebound adjusting rod). 

On the GSXR, the lock nut must be exactly 11mm from the top of the damper rod before tightening the fork top nut assembly; this allows for the correct amount of rebound adjustment.

Now the plate can be taken out, the spring compressor removed and finally the top nut can be screwed back into the fork leg. Reset your preload, compression and rebound screws to standard positions, or to your own preferred settings if you'd already experimented previously, and refit in the bike.

So what went wrong???

Where do I start? Well the bike was sat on the stand for about a week while I was carrying out work to the rear suspension when the right fork began to leak! DOH! 
By now the bike was almost back together so I decided to give it a shakedown run first before stripping the fork again. By the time I got back, the leg leg had started leaking - not impressed.

Forks back out, seals obtained from a dealer (not genuine, but Japanese made and a better feeling material), filled with oil, bled again - back in bike. No leaks, but not impressed with feel from front end. Doesn't appear to be any rebound or compression adjustment, bike reacts like a pogo stick. You can still make progress, but the front feels likes it's losing grip when leant over at high speed.

Forks back out to check lock nut adjustment (11mm remember?). All good, and oil height ok. Refit into bike, but no matter what I do to the adjustment, I can't improve the comfort and the bars are hammering my hands on every ride! So at this point I'm considering a different grade of oil, but the more I read about the K5/K6 Gixer, the more I understand that the forks are a weak point unless revalved... interesting. 

Time to give ProMechA a ring.