Kawasaki Z750S (ZR750K1 apparently)

**James Deuce** · 3rd April 2006, 18:00

What a difference! But then, you were all EXPECTING me to say that.

Derek MacAdam from Motorad did the installation and as usual did a superb job. I can't tell that the front has been dismantled and the rear Ohlins looks like a factory installation.

I have a couple of corners that give me a good idea of (relatively) high speed suspension behaviour and one slow speed corner that really tests front and rear suspension at the same time. The first couple of faster corners revealed that the steering is now massively faster than it was, and you can dial in your desired lean angle and the bike tracks true through that particular radius with no need to correct for small bumps or a slight change in camber. Fast steering and stable with it. Excellent.

The low speed, off-camber, rippled-then-bumpy test corner revealed a great deal more composure than the stock suspension could ever manage - what was that noise? Oops, footpeg touched down. No drama and way more feel when right over.

The front setup was a total gamble. Shaun Harris suggested 0.95kg Traxxion constant rate springs, and they have immediately tamed the initial brake dive I used to get on the stock Kawasaki progressives. The new springs still have that slightly stiff feel that goes away in about 500kms, but in combination with the lighter fork oil than standard, the stock valving works a whole heap better. Previously a big, sharp-edged bump would leave the front wheel hanging in space while the rebound damping caught up. No more. I can feel everything without it being a jolting distraction, like the stock springs used to be. There's no adjustment available on stock Z750 forks, so thank goodness that worked out, though I suspect that has a great deal to do with Shaun's expertise and judgement.

The rear shock is a revelation. Derek has given it a rough setup to match my weight and riding style, but I'm buggered if I can think of a single change I'd make yet.

I need to go for a decent ride now and test the suspension out a bit more. I guess many people would be a bit bemused by the wad of cash I just dropped on a "cheap" commuter, but this bike impressed me from the outset. Good handling, good power, average brakes (but then they just slow you down, right?), and good comfort until your butt gives in to the plank Kawasaki make you sit on. It tours, scratches, and commutes with no drama, and I like it.

I just wish Kawasaki would place as much emphasis on rider comfort (suspension and seat combined) as they do versatility and performance. Then it would be perfect from the word go.

Big thumbs up to Shaun Harris for the advice and patience, and the excellent pricing, and to Derek and Motorad for their usual professionalism.

**Hitcher** · 3rd April 2006, 19:47

All you need now is a hugger...

**pzkpfw** · 4th April 2006, 21:14

Originally Posted by Bob

...make sure you get to sit on one and make sure you are comfortable.
...
I've also perched on an ER-6f and we fit each other like a glove ...

Absolutely, but applies to any bike-and-rider really.

Yesterday I sat on an ER-6N, and really really hated it. The seat - narrow hard thing between my legs I do not want. The bike also just felt too short or something.

Sat on Jims' bike today; and while the seat still felt too hard, everything seemed to fit, including the tank to my legs and all that. With the seat and handlebars allowing some adjustment, I reckon it'll be just fine (for me).

I'm expecting Motorad to owe Jim a beer or two, when I buy a Z750S...

[Added later:] Orange '05 model (like Jims; but not my original choice) is now on it's way...

Can also highly recommend Motorad so far.

**James Deuce** · 11th April 2006, 07:10

Anyone able to tell me why braided brakes lines aren't a standard fitment at the factory for every bike with hydraulically actuated brake calipers?

Got the lines installed yesterday and it only took one mini-stoppie 20 metres back from the lights outside Motorad to get used to them. The Z750's brakes are characterised as "adequate" in most of the trade rags, but $120 worth of braided brake lines have turned it into a stopping demon. I had one car pull into my lane on the motorway in high density traffic trvelling at about 80km/hr.

Boy was my face red when I stopped dead, with a mere two fingers of gentle pressure applied to the front brake lever.

The best thing is the "feel" at the lever. More force equals a direct link to the amount of braking power achieved with all that rubber brake line sponginess gone.

I can stroke the brakes to adjust entry speed now. No more ham fisted squeezes to get it just about right. Makes everything much smoother.

All you blokes on 15-18 year old 250s - go get your suspension and brake lines replaced. You'll go faster, I promise.

**James Deuce** · 11th April 2006, 07:43

Oh yeah - 7000kms now.

**stevedee** · 11th April 2006, 08:07

Hey Jim did you buy the lines from Motorad or just get them to do the fitting?

**James Deuce** · 11th April 2006, 08:10

Motorad sourced and fitted the lines. They get them made up specifically for your bike.

It's really cleaned up all the lines that went over the rear of the front mudguard.

Looks great, but works waaaay better than the original lines.

**James Deuce** · 16th April 2006, 18:48

7500kms

Finally got to go for a "real" ride today. Over the Rimutakas, around the lake to Martinborough, and through the Gladstone Rd and back to Carterton.

The major improvement in handling and cornering is now evident. The old shock used to get "choppy" in bumpy corners past about 20 degrees of lean, and then the front end would get out of sync with the rear adding a pitching moment and pushing you wide just before the apex. That whole scenario had really affected my riding, and limited the amount of commitment up to the apex, and made me late on the throttle on the way out, plus I "fiddled" with the brakes a lot, cocking up entry speed, just because I wasn't sure what the heck was going on the the front-end traction department.

The Ohlins is eerily smooth at boot scraping angles of lean, and I can get on the gas a lot earlier. You can "feel" just how much traction you have thanks to a compliant spring and superb damping that actually works better the harder you go.

The front end gets better the harder you push. It can feel choppy when riding like a Nana, but up it to 6/10ths or more, and it does everything it should. Less abrupt dive means better feel on the brakes hard, both for front end traction and feel at the lever and the brake throttle transition is much smoother.

I've said it before and I'll say it again. If you are going to spend up on bling, make the first $1.5k suspension and brake improvements. It's the surest path to feeling more confident, and faster if that is your thing.

Spend the next $1.5k on healthy food and exercise. Lose 20kg and find more acceleration, top speed, and larger lean angles.

Phase 2 of the performance enhancement is starting..........

Then I could change my handle to NotSoFatJim

**airplane** · 16th April 2006, 19:14

Jim2, was that you I was talking with at the top of the Rimutakas about midday? I was on the red z1000.

I'm interested to read about your brake changes; the z1000 also has Ok brakes and some more responsive performance would be great. I think I'll ask Motorad what they can do for me.

Cheers

**James Deuce** · 16th April 2006, 19:21

No, wasn't me - I think I saw you and another Z1000 on the motorway when I was heading North and you were going South. It may have been pzkpfw, who just picked up his Orange Z750S last week. Tall skinny guy with a beard? I'm a short fat guy with a beard.

Braided lines make a massive difference and apparently Carbone Lorraine scintered pads are the go too. Removing the crossfeed pipe meant that one of the clips was removed on top of the mudguard and it left a hole showing in the guard, but a cut down panel pin from Repco blanked it off perfectly and looks almost professional.

**stevedee** · 17th April 2006, 09:38

Twas me at the top of the Rimutakas I think. Looks like the Zeds are getting more popular eh? Jim has convinced me about the braided lines, next service I'm going to organise some , but that's still a few months away.

spd:-)

**Hitcher** · 17th April 2006, 15:19

Originally Posted by Jim2

Carbone Lorraine.

Quiche's big brother?

**Gazzar** · 17th April 2006, 18:07

I am thinking of getting more sponge fitted into the seat but that is all for know the bike has done 4000ks now and i am likeing it.

Its a good balance of power and weight for me by myself or with the missers on the back. Had a good run down to Rotorua on friday and back yesterday.

**James Deuce** · 1st May 2006, 08:47

Front and rear wore out in perfect harmony, though the front was somewhat more worn than the rear. The trailing edge of each tread block on the the front Bridgestone BT019 was right down to the tyre carcass. The rear BT012R (not S as previously reported) was down to the tread wear blocks and had worn evenly across the width of the tyre.

These would be the best OEM tyres I've had on any bike but it was turning into a mission to get a replacement set.

Then I saw bugjuice's advert in Kiwirider.

Orange bike - check

Kawasaki - check

Faintly gay rider sitting side-saddle with trouser snake photoshopped onto tyre - check - I'm not buying those!

Luckily for Avon's NZ distributor, Kerry from Motorad talked me into a pair of Avon Viper Sport. Mitch then got involved and gave me shit for not getting, of all things, a pair of Bridgestone's touring knobblies, BT020s. I hate them. They're noisy and generate a small, but perceptible weave at high lean angles as the knobs, errr tread blocks dance around under whatever sport tourer/jimthefatbastard combo I'm riding

I just put it down to Mitch having one of those months, and remained committed to the Avons, despite having invective heaped upon me when I dropped the bike off (all in jest of course) for the new tyres.

Low speed handling is markedly improved, with almost no tendency to rapidly tip the bike onto it's side when using large steering inputs at low speed, unlike the Bridgestone's. The Bridgestone's steered around the front, if that makes any sense, where the Avon's feel like they are working together. I didn't get to scrub them in until last night, thanks to the weather overr the weekend, and even then the Paekak hill was damp in places, but I was really pleased with how the the bike steers, brakes, and hooks up on the exit.

Hopefully we'll get a weekend where I can get rid of the chicken strips altogether, and concurrently those silly vipers stamped into the tyres near the edge.

**erik** · 5th May 2006, 17:02

Originally Posted by Jim2

The front setup was a total gamble. Shaun Harris suggested 0.95kg Traxxion constant rate springs, and they have immediately tamed the initial brake dive I used to get on the stock Kawasaki progressives. The new springs still have that slightly stiff feel that goes away in about 500kms, but in combination with the lighter fork oil than standard, the stock valving works a whole heap better. Previously a big, sharp-edged bump would leave the front wheel hanging in space while the rebound damping caught up. No more.

Well, I've just finished measuring, measuring again, checking the calibration of my home-made spring rate measuring device, and then measuring the other spring and have come to the conclusion that the stock Z750S springs are 1.08-1.09kg/mm constant rate springs (not progressive. You can tell progressive springs by the progressively increasing spacing of the coils, the spring rate increases as the close-together coils bind).

It makes me wonder if the preload wasn't set properly for you with the stock springs?

It's going to be interesting trying them in my bandit 400.

(in the pic, the red is the measured z750s springs, the bluey-magenta colour (don't ask me, I'm partially colourblind) is what 0.75kg/mm springs would look like and the white is the stock dual-rate bandit 400 springs)