Resources

Tyres

Technical Discussion Page

  OEM tyres shown with green border  

IMPORTANT: the use of H-rated and/or non-OEM tyre sizes is by rider choice so these are displayed for interest only and should not be considered as recommended tyres for the bike.

Legend

¹ – available as a matched pair if you use a 150/60/18 or 160/60/18 rear
² – not really a ‘sports’ tyre but V, Z or even W rated!
³ – tyre sizes listed but potentially un-available in Australia

Overview

Here is Dunlop’s tyre marking explanation page and another very simple summary of tyre specifications – including why wider is not necessarily better.

The greatest tyre challenge with the GPz is the 18″ rear rim and the 16″ front rim of 1st gen bikes.

In 1984 all GP bikes were using the 16″ front so this simply translated across to the sports bikes of the time. Interestingly there are more matched tyre sets for these bikes than the later generation!

I haven’t found any definitive reason for a 18″ rear but this was certainly the standard for earlier bikes and as such there would be no logical reason for Kawasaki to try and change the wheel (pun intended) here.  Also the limitations of bias-construction may be a factor here, radials only arrived in 1987 for motorcycles so perhaps the additional rubber of the larger tyre was a physical benefit (heat?) for the tyres.  17″ rims front & back are the modern norm, so even 2nd gen bikes with a 17″ front have limited tyre choices especially if you wish for matched sets.

Having greater tyre options is an often quoted argument for changing the rear rim.

As mentioned although the rim sizes vary on the two generations of bikes the calculated diameters of tyres for all version is virtually identical.  Given the bikes potential performance I strongly suggest V-rated tyres (150mph) would be the minimum specification for safety & insurance, there is even an unexpected Z-rated (168mph) option for +A7 bikes (curiously an adventure not sports tyre!).  However there are far more tyre choices available if you include H-rated (130mph) tyres that some owners choose to fit, so I’ve also listed these for interest.

Version Front Rear
A1-A6 120/80/16 (∅598mm) 130/80/17 (∅665mm)
A7+ 120/70/17 (∅600mm) 150/70/17 (∅667mm)

Tyre Pressures (cold)

The service manual specification (1990-93 model radial tyres) is to run F: 36psi & R: 41psi.   IMHO you need to take these with a grain of salt, because in 2020 with my Dunlop RoadSmarts I cannot run anywhere near that pressure at the front – it feels like you are riding on a solid piece of rubber.  Might be fine on the race-track but on the road I drop to 29psi, as anything below that the front begins to get ‘squirmy’.  I then set the rear by the same 5psi offset, so 34psi.  And that is still so firm I had to drop the rear shock pre-load!

V vs H-rated tyres

The minimum specification for the GPz900R is a V-rated (149mph) tyre, which is logical for a 150mph bike and of course higher speed rated tyres (Z or W) would be perfectly suitable as well.  However….many riders use tyres that are only H-rated (130mph) such as the 130/80/18 Pirelli sport Demon.  I would personally not use anything rated less than V, however others may choose to do so based on their riding.  So I have included these for interest.

I would also strongly recommend confirming using a H-rated tyre doesn’t negatively affect your insurance!

Smaller diameter tyres

Smaller tyres reduces clearance, shortens the gearing (note speedo runs of front wheel) and changes the geometry of the bike to be even more tail heavy.  If you haven’t done it already you can rotate the rear chain adjusters to raise the rear axle.

Folks who modify to the ‘easy swap’ ZZR600 rear rim may need to consider more significant modifications (such as longer rear shock length) to correct the geometry and gearing effects of the even smaller 160/60/17 tyre (∅623mm).

Note: +A7 bikes have no ability to lower the triple-clamps on the front forks.

Wider tyres

There’s handling arguments against wider & lower profile tyres, the most obvious is that the greater profile radius means the bike won’t naturally turn in as easily.  But that is potentially balanced by the  ‘pinching’ effect you would get putting this onto the smaller rim and the original profile of the tyre itself – which can vary significantly between products.  The greater contact patch also potentially creates ‘push’ especially when cornering – analogous to understeer in a car.

On the positive side a wider tyre typically is softer riding due to more material.

150/60/18 (∅637mm)

Provides a few different matched set options for +A7 owners.

160/60/18 (∅649mm)

Maybe.  For +A7 owners (MT3.5″ rim) if you use this rear size that gives you many more Z-rated (even W) radial tyre options.

The general consensus of public opinion is that a rim can run up & down one standard size – manufacturers might think differently of course.  As there is minor dimensional variances with tyre manufacturers specifying in the middle is the correct choice – or better yet specify a particular product that fits perfectly, which is exactly what Kawasaki did.  One group member mentioned how he used a Dunlop Track Endurance way back in 1985 – the 130 looked as wide as other brands 150’s!  Of course none of the OEM spec tyres are available now, so it’s possible that a ‘slim’ modern 160 tyre might fit better than another ‘fat’ modern 150 – I simply do not know.

The only way to confirm would be to test different 150/70 & 160/60 tyres on different width rims and compare the tyre profiles. Kinda difficult…

Note: to fit even wider tyres/rim usually need an offset front sprocket and many replace the swing-arm, this is discussed in more detail here.

190/55/18 (∅666mm)

FYI the 4.5″ rear rim of the ZX-10 Tomcat (ZXT00B) can run this tyre which is identical in diameter to OEM, however not in the stock swing-arm.  I find it difficult to believe that this rim/tyre combination is lighter but have some feedback is that it actually is.

Bias (cross-ply) vs Radial tyre construction

Although radial construction is a ‘newer’ design, many modern bikes like cruisers still have bias tyres as OEM. I would certainly NOT recommend bias-construction tyres on a modern superbike, however it’s not an apples-vs-apples comparison, as variations of weaves & materials all mean a different result.  Of course each manufacturer considers their design to be the ‘best’, but then again over 50% of drivers think they are better than average.

Link discussing the two types of construction.



Also the early 1980’s were a significant time in tyre development.  Michelin introduced radials into racing in 1984, and released the first road bike tyers in 1987.  Although the A1 had the widest tyres ever fitted to a Kawasaki, from the service manual specifications  it looks like it was only with the 2nd gen bikes (+A7) that radial tyres (Michelins) tyres were specified as OEM.  So the GPz was probably designed to use bias-construction tyres, maybe a factor as to why the geometry is ‘slow’ compared to modern bikes.

The first vehicle to have radial tyres fitted as standard was the Citroen 2CV in 1948 (or 49) – a cool car but hardly ‘sporty’!

It stands to reason that not only have radial tyres developed a lot further since then (so have greater influence on modern bike engineering) but also that the GPz900R engineering would probably still be quite happy with modern bias-construction tyre, which would *hopefully* be much better than what was available in 1984!   This is a ‘score’ of the original rear tyre Dunlop K727 – hardly confidence inspiring numbers!



Although still bias construction the ‘ancient’ Bridgestone BT-45 (only superceded in 2020 with the BT-46) is one of the universally recommended tyres for A1-A6 bikes and I have personally run the 120/70/17 front without any adverse handling issues at all.

As such you can do your own research and decide which tyre construction suits your riding style – IMHO radial gives sharper handling but a much firmer ride.

Lastly it is definitely NOT RECOMMENDED to mix the two tyre constructions, although curiously in the early days  sometimes racers actually did just that.  Just goes to reinforce how the most important factor in motorcycling is the rider.

Need to do homework

One of the complexities when searching manufacturer or retailer sites is that they do not always recognise the different generations of bike or even the bike full stop!

For example when searching (Nov 2020) www.bridgestone.co.uk and choosing the GPz900rR you cannot select a year, and the only tyres returned as suitable are the BT45 with no listings at all for the either the BT46 or the BT016, despite these being available in Australia for both 1st & 2nd gen bikes.  So if a major manufacturer from a major country can’t get be bothered to get their online site right for our bikes – that gives insight into the challenges of hunting down tyres!

Other sites like Pirelli only offer searching by bike make & model, so if there isn’t OEM tyre sizes available you won’t get any matches.

Local online sites

I’ve added the manufacturer marketing ‘blurb’ for interest and for comparative pricing I also have snapshots from an Aussie online supplier motorcycletyrewarehouse.com.au. Personally I purchase tyres directly from my local Adelaide tyre fitter – dcmotorcycles.com.au

84-85 Service Manual Tyres

Note: no idea why tyre pressures are different for US & Canadian models.  Beautiful, but Canada can hardly be described as hot so ambient temperature can’t be relevant., The only performance difference is that bikes for these markets were slightly detuned for 110hp rather than the standard 115hp, however the Swiss model only had 69hp so there is no logical connection with power either.

Front: 120/80/16 V250 Dunlop F-17 Cold Pressures : US/Canada – 32psi elsewhere 36psi

Rear: 130/80/18 V250 Dunlop K727 Cold Pressures: US/Canada – 36psi elsewhere 41psi

86 & 88-89 Service Manual Tyres

The 1986 supplement lists the following additional tyres.  The 1987 supplement doesn’t make any mention of tyres, yet the 88-89 supplement includes these again. A bit inconsistent.

US/Canada specs only specify the Dunlops as per 84/85 models.  Europe has a couple of extra tyre options though.

Front: 120/80/16 V250

Dunlop F-17 Metzeler ME333 Laser Avon Super Venom AM17

Rear: 130/80/18 V250

Dunlop K727 Metzeler Perfect ME99A Avon Super Venom AM18

 

 

 

90-93 Service Manual Tyres

So along with other changes the 2nd generation bikes are the first to be specified with radial tyres.

Front: 120/70V17-V250 or 120/70ZR17  Cold pressure: 36psi

 

Dunlop K25F Metzeler ME333 Laser Metzeler ME1 COMPK Michelin A59X

Amazingly

no

image!

 

Rear: 150/70V18-V250 or 150/70ZR18 Cold pressure: 41psi

 

Dunlop K275 Metzeler ME1 COMPK Michelin M59X

 

 

 

+A7¹ Conti Road Attack 3 (Z)

RA2 Info Link

RA3 Info Link

Oz Importer Link

160/60/18 Rear

The Allround tire with the highest standards in the sport touring segment.

Performance oriented pattern design for better drainage in wet conditions.
More improved wet grip due to an optimized compound.
The EasyHandling technology bestows the tire with linear handling even if stabilizing gyroscopic forces are nominal (e.g. when turning). Simultaneously, accuracy and groundingfeeling are improved at benchmark level – applies to all riding situations in this segment.
Comfortable and easy for all demands, whether on long rides or winding roads.
Balanced characteristics from the first to the last mile.
TractionSkin, a revolutionary new micro-rough tread surface, virtually puts an end to tire break-in. This is possible due to a new mold coating technology which eliminates the need for tire-release agents.
MultiGrip makes it possible to use a homogenous grip grading with a single compound thanks to temperature controlled curing of the tire during the production process.

The Road Attack 2 Classic Race was available in a 150/65/18 – which was a nice alternative option for the rear.  Unfortunately NA unless you buy old stock from eBay, in Feb 2021 some (9) were still available with a manufacturing date of late 2012. Some folks say the max storage life is 6 years, others say 6-10, so either way these are old stock.  Not much cheaper that other newer tyres either.

Feb 2021 Update

According to Continental a matched pair using the 160/60/18 is still available in the new generation RA3 and I have confirmed with the Australian importer Ron Angel Wholesalers that they are bringing the RA3 sizes in, though they didn’t currently have the rear in stock. Note motorcycletyrewarehouse.com.au is only showing the RA2 range.



Reviews

A few years ago I ran Road Attack 2 tyres with a 150/65/18 and really liked using them.  I was getting back into bikes and these were grippy and the smaller rear tyre meant the bike felt very planted & secure whilst I was figuring out how to ride again.  I don’t think they are designed for longevity!  The only gripe was a very fine buzz through the perfectly balanced front tyre – which was kinda odd when you look at the consider the blockier tread pattern of the BT45 that replaced it.  Unfortunately Continental had discontinued importing this size in the RS2 range which was the only reason why I changed.

A1-A6: Conti Go! Allround (V)

Info Link

Oz Importer Link

New developed cross-ply tire for all-round use.

Perfect grip under all weather conditions for all-year-round use.
Excellent mileage due to up-to-date compound technology.
Innovative tread pattern design for even wear and good water dispersement.
Improved carcass construction for easy handling and high stability.

Feb 2021 Update

I have confirmed with the Australian importer Ron Angel Wholesalers that they are bringing these in.



 

+A7² Conti Trail Attack 3 (Z)

Manufacturer Info Link

Oz Importer Link

Our most agile On- / Off Road Tire, 100% trust from start for modern and powerful Adventure Tourers

100% TRUST: super short warm-up time – reaches his optimal temperature range within the first 1.500 meters*
BENCHMARK IN WEAR: the tire has after 3.500 km still more tread depth then a new benchmark tire and gives you better handling abilities**
PERFORMANCE OVER TIME: Built to ensure highest constant level of performance even after thousands of kilometers due to a mix of MultiGrip, carcass construction and pattern design
WET GRIP: Best wet grip achieved by compound & pattern design
AGILITY: Most agile All-rounder for easy, accurate and predictable handling
COMFORT & STABILITY: high level of comfort, absorption and stability even on challenging road conditions

OK – designed for adventure tourers rather than a sports bike BUT they are designed as 80% on-road AND have a speed rating of 168mph!  Just goes to show how much faster all types of bikes are these days, and the tread pattern shows plenty of rubber on the road.  Given their speed rating I’m wondering if these would be similar (or better?) in performance to bias tyres.

Feb 2021 Update

I have confirmed with the Australian importer (Ron Angel Wholesalers) that they are bringing in the 120/70/17 58W as well, even though  motorcycletyrewarehouse.com.au only shows the rear in the older Trail Attack 2.



Review – N.L (UK)

The Conti trail attack 150x 18″ rear, don’t be put off thinking this is a trail bike tyre. Although not used on a gpz i’ve gone through about 10 of these on my KTM 990, all road use and it is a stonkingly good all round tyre that will outperform most riders – gives lots of confidence feedback, i’ve had a few minor – under power slides – typical corner exit and its fun – you get lots of warning and it happens progressively – the confidence side continues when on wet roads – – I suspect a potential advantage for the GPZ could be this tyre may help reduce harshness in the rear suspension – at least you have a range of sidewall stiffness to choose

+A7³ Dunlop RoadSmart (Z)

Oz Manufacturer Info Link (RoadSmart)

Oz (most states) Importer Link

International RS2 Info Link

International RS3 Info Link

International RS4 Info Link

Roadsmart features a new pattern with higher groove concentration in the central tread area to maximise wet performance . The “Triple Tread” rear construction places the traction compound in this area to enhance tyre life, whilst the ‘Flex Steel’ jointless belting system increases high speed stability by better absorbing shocks from road surface imperfections . The “grip” compound is is placed in the shoulder section to give high wet and dry grip performance in turns.New compounds have been developed for this latest sport touring tyre from Dunlop using ultra fine carbon enriched with silica.

So according to the international sites nothing fits – even though I have these on my A8 right now (Feb 2021).  The Aussie Dunlop link lists both the 150/70/18 or 16/60/18 rear rim sizes BUT the Australian importer link shows nothing but 17″ rears.

Feb 2021 Update.

My understanding is that Dunlop were making 18″ rears, even for the RS4, but have either discontinued production or are simply not bringing into Australia.  Great. Last year my local tyre supplier told me there were just FIVE 18″ rears in Oz, 4x RS3 & 1xRS4, so I ordered a spare so at least I can refit these next time.  No problems getting fronts.  So I can’t imagine there are many locally, however ‘old’ stock still appears to be available from www.motorcycletyrewarehouse.com.au 

Owner Review

At my last re-tyre a pleasant surprise with more tyre choices this time, Dunlop making/releasing an 18″ rear letting me use the OEM sizes of 120/70/17″ front and 150/70/18″ rear.  Note I did use the RS2 on the front (rather then the RS3) for a couple of reasons.  My tyre guy (small owner business) had one already there from an earlier cancelled order and offered it at a discount.  So sure, I could have pushed for the newer one, but I like to help support my local small businesses and it saved a bit of coin.

Wow….different.   I’ve read that the reason the GPz ride is hard at lower speeds is because the engineers designed it for +100mph stuff, and to be honest they were also probably thinking of the nice smooth highways of Japan (or the racetrack) rather than a typical Australian country road!  And these tyres are firm and quite sensitive to tyre pressure!

The A8 has no front forks pre-load adjustment and they have just been serviced with new oil and seals, so it’s pretty close to spec.  And yes, I have adjusted my rear shock to give some static sag!

I’ve adjusted the front to be 29psi – noticeably firmer than 28 (wriggly) but noticeably softer than 30.  Yes, this sensitivity surprised me too.  IMHO you can’t go higher – it’s just too much work.  Higher PSI makes the bike more agile, but the front crashes and bashes through bumps so you end up having to work & concentrate hard to counteract road imperfections.  Ultimately it isn’t all that enjoyable, and nd that’s for roads where I already know where the bumps are.

I normally simply set the rear at +4psi from the front, I suspect there is more ‘range’ at the rear-end as well.  But make no mistake the ride is still firm – there’s several known bumps where if I’m not standing up off the seat it’s helium time.  I had read some riders of bigger bikes (GPz is 222kg…) had front-end lift at speed with these tyres.  Well there is nothing of that with my set-up.  At within reason road speeds the bike is incredibly stable and secure – brilliant really.  Grip is also astounding – wet or dry.

Update: had a chance to cruise a racetrack recently – at 220km/h on the straight there was zero front end lift, so I suspect this is more to do with the tyre on a particular bike setup rather than a trait of the tyre itself.  And on the smooth surface of a racetrack, even at cruising speeds, these tyres felt absolutely fabulous and IMHO would be quite fine for a more competitive track day.  You could definitely run higher psi.

Summary

IMHO these tyres match the design intent of the bike.  Agile, grippy – it’s biased to performance and they significantly improve agility over the BT45/Avon combo.  The best way to describe then is that they give you more range – ie you can be less precise with entry lines and speed because it’s really no drama to make mid-corner corrections if required.  They really do make the bike feel lighter and increased agility improves city riding dynamics as well.

Are they better than the Contis?

Too long between drinks to really compare, but my memory (fading) says these are more precise – but definitely firmer.

Are they better than the BT45/Avon combo?

If I were mainly touring then I probably wouldn’t keep these – a softer ride, especially at the front, is simply more relaxing for long journeys.  So it all depends on how you like to ride your GPz900r!

I’ve stuck with these because I do like the twisty stuff and these tyres are more fun to play with, but I would have been just as happy with the BT45/Avon combo as well.  But the next set will be the Dunlops…if I can still get them

+A7: Dunlop GT601 (H)

International Manufacturer Info Link

Oz (most states) Importer Link

The Arrowmax GT601 line-up complements the StreetSmart range, to form a formidable line-up in highly performing sport-touring bias tyres.
Silica blend compound for stable grip in all conditions, with high abrasion resistance and great wet performance
Combining our popular Wide Parallel Grooves with the latest simulation technologies for tuning pattern rigidity
Responsive and smooth handling, with ample feedback even at high lean angles

Details on this H-rated tyre aren’t listed at the Australian Dunlop site.  The international link doesn’t list the 120/70/17 front BUT it is listed on the OZ importer catalogue AND available at motorcycletyrewarehouse.com.au.  Although only H-rated I suspect it’s a close thing, as several sizes are V-rated including a 130/80/18 rear – unfortunately no 16″ sizes though.

Feb 2021



A1-A6³ +A7³ Dunlop GT501 (H)

Manufacturer Info Link

Australian (most states) Importer Link

Tasmanian Importer Link

  • The Tasmanian importer is a link to the 2016/17 Dunlop Catalogue PDF – 99% sure many sizes are no longer available in Australia.
  • Tread looks identical to Dunlop Streetsmart but the listed available sizes slightly vary and they come up as different products below.

The fourth generation of the famous Arrowmax line incorporates all the lessons learned over 15 years of Arrowmax development . State of the art Aramid fibreglass belted designs give precise steering and handling as well as greater mileage by bracing and stiffening the tread area . Large range of ‘V’ &’H’ speed rated sizes to suit bikes from 250cc upwards. All sizes tubeless.More value and mileage than previous Arrowmax models by increased tread depth.

According to Dunlop all sizes are available for both generations of bikes, however this particular tyre IS NOT listed AT ALL at the Australian (most states) Importer Link – the closest they have is the 150/70/18 rear GT502, a V-rated tyre for Harleys. So although there are sizes to suit +A7 bikes listed as available at motorcycletyrewarehouse.com.au  it’s likely that this is old stock.

Feb 2021



A1-A6 Pirelli Sport Demon (V+H)

Int Manufacturer Info Link

AN X-PLY TYRE FOR MOTORCYCLES DESTINED FOR TOURING

Uniform and progressive performance in all riding conditions thanks to the rear multi-radius profile
High grip on wet and dry surfaces with excellent mileage
A safe and reliable tyre in all riding situations, with a particularly favourable cost/quality ratio suitable for Sport Touring motorcycles

The Pirelli site is pretty good matching the available tyres to the bike however being so specific and only being able to search by bikes means you can’t easily search for any ‘close’ matches with the 160/60/18.  Note that the front is V-rated, the rear H-rated, though again I suspect it is a close call.

Feb 2021

It is  available online at motorcycletyrewarehouse.com.au

A1-A6 Dunlop Arrowmax StreetSmart (V)

Int Manufacturer Info Link

Oz (most states) Importer Link

Sport touring bias tyre with modern technology for classic bikes.
Ideal for lightweight and classic bikes
Stylish design
State of the art performance
Innovative compounds with tailor-made silica optimise the balance between wet grip and mileage

Note: Tread looks identical to Dunlop GT501 however sizes cary slightly and they come up as different products below.

Although the international site lists size to suit 1st gen bikes the official Australian importer for Dunlop tyres, ficeda.com.au, do not actually list this tyre at all!  It is however available online at motorcycletyrewarehouse.com.au

Feb 2021



 

+A7¹³ Michelin Pilot Road 2/3 (W)

Oz R3 Info Link

Oz R2 Info Link

A combination of technologies for better grip on wet surfaces, for longer periods of time. Ride with total peace of mind in all types of weather!

160/60/18 Rear

Note this size is not available in the 4 or 5 range .

Feb 2021

Although theoretically available only some sizes from the Pilot 2 & 4 range are available online at motorcycletyrewarehouse.com.au with no 18″ rears.  I’ve just included a 17″ rear to show an indicative price.

160/60/18 availability unconfirmed.



+A7¹ Pirelli Angel GT (Z)

Int Manufacturer Info Link

160/60/18 Rear

THE HIGHEST MILEAGE SPORT TOURING TIRE: 100% ITALIAN GRAN TURISMO

  • The ideal tyre for travellers using the bike for long road trips, with side bags and passenger, looking for safety on wet, stability and mileage
  • The evolution of the Angel™ ST, stretching the concept of Sport Touring into Gran Turismo, bringing the sporty attitude to a wider range of usage conditions and for longer distances
  • The new reference for mileage in Sport Touring tyres
  • Excellency in wet performance and grip
  • Top handling capabilities, typical of the Pirelli DNA
  • Performance consistency until the end of the tyre’s life
  • Bi-compound
  • Personalisable through sidewall rubber labels

Another sports tyre you can use as a matched pair when using the 160/60/18 rear.

Apr 2021: An owner who purchased these reported that these are very stiff tyres and very difficult to get onto the rim, the front being the hardest.  He runs 36/41psi.

Feb 2021

Superceded bythe GT II which of course drops the 18″ rear.  The ‘old’ GT is still available online at motorcycletyrewarehouse.com.au



+A7¹³ Metzeler Roadtec Z8 Interact (V)

Oz Manufacturer Info Link

160/60/18 Rear

ROADTEC™ Z8 INTERACT™ ensures peace of mind in the hardest situations, in the cold or wet, providing ideal handling for true riding pleasure.

Riding easiness, comfort, predictability, easy turn in, progressivity in lean, are provided by the interaction of sport touring profiles with the Greek π tread pattern and the patented Interact™ technology.Interact™ is the multi tension technology allowing Metzeler tyres to offer the best performance in all conditions; the differentiated tensioning of the steel belt underneath the tread compound gives a tailored performance.High steel belts winding tension in the center reduces compound movement and increases stability of the footprint area which reduces wear and ensures high speed stability
Low steel belts winding tension creates more flexibility and energy absorption, the compound increases the temperature and becomes softer, offering more grip while leaning
The variable winding process of the 0° steel belt guarantees a progressive behavior at different lean angles without discontinuity of performance

 

Feb 2021

Another sports tyre you can use as a matched pair when using the 160/60/18 rear, however only the front is available online at motorcycletyrewarehouse.com.au, I’ve used a 17″ rear for a price comparison.

160/60/18 availability unconfirmed.



+A7² Metzeler ME888 Marathon (V/H)

Oz  Info Link

Metzeler ME 888 MARATHON™ ULTRA is the best partner for long and safe travelling on cruiser, tourers and their custom versions.
To achieve this targets, Metzeler designers finely combined the specifications which determine the characteristics of tyres: profile, structure, tread pattern and compound.
The structure shape features a flat and wide geometry that conveys and dissipates toward the sidewall the stress generated under the footprint, reducing the fatigue and the wear process.
To increase wear regularity, the transversal grooves of the tread pattern are discontinued by ‘compound bridges’, resulting in a more solid and stiffer tread design that reduces the stress transmitted to the belts and carcass plies.
Also the edges of grooves are critical areas for wear regularity. ME 888 groove walls have different inclination to ensure the best operating angle in every position.
The polymers of the compound are abrasion resistant, providing higher resistance to wear and hence high mileage.

A ultra-high milage cruiser tyre and although the official Metzeler site doesn’t included sizes (duh!) other international online stores suggest the OEM +A7 tyre sizes are available, V-rated front & H-rated rear.

Feb 2021

Both tyres available at motorcycletyrewarehouse.com.au.



A1-A6 +A7³ Bridgestone BT-46 (V or H)

Int Info Link

Oz Importer Link

The Battlax BT46 is set to replace the iconic Battlax BT-45. Since its introduction 22 years ago, the Battlax BT-45 has been the go-to tire for touring. Now, Bridgestone has upgraded this design with modern technology.Wet performance has been upgraded from the BT-45,with no impact on the predecessor’s well known dry handling performance and wear resistance.

From Bridgestone is the replacement for the ancient BT-45V (though not as old as the GPz!) with matched V-rated tyres for the A1-A6 versions.

I suspect this tyre will follow on from the BT-45V reputation as a reliable touring tyre (I found it very ‘comfortable’) and it uses exactly the same tread pattern, so it remains to be seen if the tyres suffer the same side-wall scuffing/scolloping that afflicted the BT45’s if they are ridden with spirit through the twisties.

Feb 2021

There are tyres listed as available for the later +A7 bikes but curiously the 120/70/17 front is only H-rated (210km/h). Also the rear is not currently available on motorcycletyrewarehouse.com.au

+A7 availability unconfirmed.



+A7 Bridgestone BT-016 (V)

Info Link

Oz Importer Link

Sports radial for 80’s custom motorcycle! Maintains performance level throughout the life of the tire

As it stands at Feb 2021 these are the only sports tyres for the +A7 that come in OEM sizes.  Definitely used and recommended by other forum members.

Feb 2021



A1-A6³ Bridgestone BT-45V (V)

International Info Link

Oz Importer Link

The definitive touring bias tire. A proud best seller with total high performance to meet the needs of the user

A staple for the bike, although it is still listed in the 2020 importer catalogue it has been superceded by Bridgestone with the BT46 so is no longer listed on the official information sites nor are any suitable sizes available from www.motorcycletyrewarehouse.com.au.

+A7¹ Bridgestone Battlax T31 (Z)

Int Info Link

Oz Importer Link

160/60/18 Rear

A significant improvements in wet performance leads to a feeling of safety. The ideal sports touring radial, able to cope with a wide variety of riding conditions.

Feb 2021 Update


+A7¹²³ Bridgestone Adventure A41 (Z)

Int Info Link

Oz Importer Link

160/60/18

An Adventure Type tire that has evolved in all aspects to offer outstanding straight-line stability and performance in the wet, in addition to satisfactory wear life.

Feb 2021

The 2020 importer catalogue lists all the sizes including the 160/60/18 – however as it is not currently available on motorcycletyrewarehouse.com.au I have added a 17″ rear for a price comparison.

160/60/18 availability unconfirmed.



+A7²³ Metzeler Tourance Next (V)

Oz  Info Link

The Enduro Street tyre that dares you to challenge any weather condition and any road

Feb 2021

Although listed on the Oz Metzeler site the 18″ rear is not available at motorcycletyrewarehouse.com.au, I’ve just included a 17″ rear to show an indicative price.

150/70/18 availability unconfirmed.



A1-A6 & +A7: Avon AM26 RoadRider MkII (V)

Int Info Link

Designed for motorcycles of all ages, the Roadrider MKII provides a step forward in performance and reliability over its predecessor.

The only tyre that I have found that comes in sizes to suit all versions of the bike.

Note: despite the international site reporting that this tyre isn’t available in Australia you can buy it online at motorcycletyrewarehouse.com.au.

Feb 2021



+A7¹ Avon Spirit ST (Z)

Int Info Link

160/60/18 Rear

Avon’s latest hypersport touring tyre with exceptional wet grip performance and mileage. Manufactured in the UK.

Note: despite the international site reporting that this tyre isn’t available in Australia you can buy it online!

Feb 2021



A1-A6 Metzeler Lasertec (V)

Oz  Info Link

Heritage tread pattern and modern technological solutions to enhance style and performance of the motorcycle

Feb 2021



150/70/18²³ Avon Cobra AV72

Int Cobra Chrome Info Link

The Avon Cobra Chrome is our newest offering aimed at the power cruiser/touring/custom market featuring premium performance, a stylish Cobra themed design and a wide range of sizes.

Note that the AV72 has been superceded with the Cobra Chrome.

This tyre was run in combination with a BT45 front, as neither tyre comes in a matched pair.  The tyre choice (suggestedby my fitter) followed on from Conti Road Attack 2’s which were no longer available in the 150/65/18 rear.  The intent at this change was for a longer-lasting tyre rather than performance, I had recently made the pilgrimage to Philip Island and the Contis wear horribly in a straight line.

Review

Firstly I really liked the design, much more than the new Cobra Chromes actually.

Of course these are not performance tyres, and they handle at least two levels below the Dunlop Road Smarts that replaced them.  But they weren’t bad at normal road speeds and were still very secure & predictable when cornering.  It is only when really riding with spirit that you notice a difference, faster more precise tipping in and much quicker & easier changes of direction.

Ultimately the most the greatest difference was comfort – the bias-tyres are much, much friendlier.  I had to drop the rear shock pre-load by two complete turns with the Dunlop otherwise hitting road bumps was like riding a bucking bronco.

IMHO the GPz ride can never be described as comfortable, so if touring or highway riding is your riding priority I would take this Avon over the Dunlop every day.

Never had any dramas in the dry or wet, however the only really quirky  issue I had with the Avon was that it would ‘shimmy’ (as opposed to slide) over surface transitions. Initially very disconcerting but ultimately it also very predictable, so just became something that you got used to.

 

+A7³ IRC Road Winner RX-01 (H)

Int Info Link

A sport-bias tire with well-balanced abrasion resistance and grip.

A mix of narrow and wide grooves provide a flexible tread surface for superior road grip and traction on wet roads.

Stronger casing construction provides improved straight-line stability.

Feb 2021

The manufacturer site lists 120/70/17 & 150/70/18, curiously they specify a MT4.0 rim for the rear tyre.  However apart from some used sizes available on eBay.com.au I haven’t found a local Aussie supplier.  Looks like readily available in the US (inc Amazon) & also available online at japan.webike.net

Availability unconfirmed.

+A7³ IRC Road Winner RX-02 (H)

Int Info Link

The RX-02 is an updated, all-around, sport, bias-ply tire based on the rider-favorite RX-01. We made a number of technical upgrades that boost performance on wet roads by 10 percent and reducing tire wear by 20 percent when compared to the RX-01, yet maintain the “easy handling” of the tire.

We added the latest compound technology to many of our new tires to improve grip on wet roads and reduce tire wear on advanced sport and touring bikes.
A new tread pattern is arranged linearly from center to shoulder, making neutral handling possible and improving grip performance in dry and wet conditions while maintaining balanced wear performance.
Front tire design was focused on neutral handling while design of the rear was focused on stability.

Feb 2021

The manufacturer site lists 120/70/17 & 150/70/18, curiously they specify a MT4.0 rim for the rear tyre.  However the only local supplier I have found is at wrp.net.au however they only list a single rear size 150/70/70 for $159.94.  Looks like readily available in the US (inc Amazon) & also available online at japan.webike.net

Availability unconfirmed.

+A7¹ Dunlop Alpha 14 (H)

Oz Importer Info Link

brm.co.nz review

150/60/18 Rear

Designed for small (ie 250!) track bikes it is road legal and definitely looks the most track oriented tread design – of anything here.  Only H-rated and there doesn’t seem to be any official manufacturer link – which is odd. Would need to confirm load rating. 

Feb 2021



+A7¹ Shinko 006 Podium (W & V)

Oz Info Link

150/60/18

006 Podium offers streamlined tread pattern reducing rotating resistance while improving water drainage. The 006 Podium offers a wide range of fitments and across 16″, 17″ and 18″ for custom bikes and original fitment on some imported motorcycles.

Features include;

  • Smoother shoulder profile insures superior grip and exceptional stability at all lean angles
  • W(168 mph) or V(149 mph) rated
  • Aramid belted
  • DOT approved
  • 16″, 17″, and 18″ sizes available
  • Intermediate rubber compound

Feb 2021

The local site site lists 120/70/17 W-rated & 150/60/18 V-rated  with prices, however the tyres are not listed on motorcycletyrewarehouse.com.au despite Shinko being listed as a brand here.



+A7² Pirelli Night Dragon (Z /H)

Int Manufacturer Info Link

THE CUSTOM CRUISING TYRE WITH THE PIRELLI SPORTY FEELING
 
  1. Better adherence, road holding and look than standard tyres for Custom/Cruiser motorcycles
  2. Designed for Custom motorcyclists that need tyres with high performance on the straight and inclining
  3. Excellent grip and a higher mileage
  4. Great fun to ride with a good balance between reliability and life of the tyre
  5. Optimised for the new V-Twin engines with more power and higher torque
  6. EPT technology of sporting derivation to optimise the area of contact in order to ensure great stability at high speeds and lightning acceleration

 

Feb 2021

Although available online at motorcycletyrewarehouse.com.au the front is not listed at the official Pirelli link.



3 + 2 =

GPz900R (ZX900) Database

Number of owner contacted & confirmed bikes.

A1

A2

A3

A4

A5

A5A

A6

A7

A8

A9

A10

A11

A12

A13

A14

A15

A16

Top Gun

About the Site

My family loves older vehicles, the newest one we own is 2003!  But I am acutely aware of the ownership complexities especially:

  1. they often need more 'hands-on' mechanical work &;
  2. there often isn't any local expertise from the service centres;
  3. there is often no new parts available from the manufacturer;
  4. parts often have to be sourced 2nd-hand or from overseas.

So we often end up doing a lot of the research & work ourselves and this information gets stored either locally with the bike or online forums - although finding the useful parts in these forums isn't always simple.

The original goal of the site was simply somewhere for me to record service work & contacts on my GPz900r so that my kids (the one that likes bikes anyway!) could easily access it - it doesn't concern me if it was publicly available.

I then realised that with this online structure in place I could also offer it to other owners, and the site could potentially expand to record other owners experiences and expertise , meaning we can learn from others but also pass on this knowledge to subsequent owners of these wonderful motorcycles.

At least Covid-19 has given me plenty of spare time to pursue my passion for the motorcycle!

Location

Adelaide
South Australia

Email

gpz900r@motoshoot.com.au

Timeline

1983 - Honda XR200
1984 - wanted a GPz
1985-2013 - cars+family
2014 - finally got one!

Disclaimer

The information provided on this site (or links) is personal experiences from non-professional home-mechanics, so neither it's accuracy nor it's validity can be confirmed.  If you need professional advise please visit your local Kawasaki dealership or a qualified industry professional.

Like riding any motorcycle, at the end of the day the only opinion that really counts is your own!

The site is 99% free to use & your participation is most welcome. 

In Apr 2021 I started a GoFundMe campaign to purchase unusual but relevant resources such as microfiche.  As it is often not economical nor logical for individuals to purchase these items (eg. why purchase A1 info when I have an A8?), this campaign shares the purchasing & processing cost amongst many owners and over time potentially benefits everyone.

For their support only campaign contributors will have access to purchased resources, however this will only be a very small part of the site and all other information will remain completely free.

So if you enjoy the site and share my passion for the GPz900R, please consider donating to the campaign.

 

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