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Thread: Zrx1100/1200 Faq

  1. #1
    Join Date
    Jun 2005
    Gremlin Towers, Stourbridge

    Zrx1100/1200 Faq

    Autors note: This topic will hopefully be of more interest to our newer members but can be used as a quick reference by our more established Rexers. What follows should hopfully reflect the views of the majority of the membership. Please read the disclaimer at the top of this forum before following any advice given in this Faq.

    Also, much more technical / modding information can be found in the Members Only Area in the Pitstop forum, which you can access after you have written more than 20 posts.


    As with any purchase, you get what you pay for so it's advisable to set a budget for as much as you can reasonably afford allowing a bit of spare cash for modifications repairs and improvements.
    On the whole, the ZRX has proved to be a good solid bike with no consistantly reported faults or failings. The motor itself is a de-tuned ZZR unit and as such is less highly stressed and with regular routine maintainence should give many miles of trouble free service. Service intervals are every 4000 with a major every 8000.

    The ZRX isn't fitted with a centrestand. That braced swingarm on both the 1100 and the 1200 models would make this impoosible/impractical to fit. (At least the ZRX has a valid excuse for no centrestand unlike the majority of sportsbikes around at the moment.)
    If you intend doing your own maintainence then sooner or later you're going to need to get the wheels of the ground, if not off the bike altogether. Most of us here have at least a paddock stand for the rear if not one for the front too. Once the rear is supported on a paddock stand it iis possible (with care) to jack the front up. If doing this, then a suitable means of supporting the front of the bike such as axle stands , blocks of wood or even a pile of books (don't laugh, It's been done) is advisable. The jack alone is not a recommended support as it may either collapse due to instability or if hydraulic, leak slightly and let the bike down.
    Paddock stands can be a little awkward to use single-handedly untill you get used to them. Many members favour the Abba Superbike stand which promises easy one man operation and of course does what it is intended to do. See here for info.
    Even a basic maintainence task such as lubing the chain, although possible on the sidestand is easier with the rear wheel elevated.


    The Standard ZRX is shod with Bridgestone 020 tyres which are perfectly adequate for the job. Many members used to favour the slightly softer 010 compound which offers a little more grip in all conditions but at the expense of mileage. If touring and commuting are your thing then best stick to the 020. The 010 has been superseded though.

    The pressures quoted in the Kawasaki Owners manual are in fact incorrect, according to Bridgestone. The tyre manufacturers quote front/rear at 36/42 psi. Running at these slightly increased pressures many of us have reported improved handling and durability. At least 2/3 of our membership run at these pressures. The other 1/3 have experimented and found a pressure that suits them best. Nobody seems to use the pressures quoted by Kawasaki.

    Some members have reported that on changing from Kawasakis' recommended pressure (incorrect) to Bridgestones 42 that it made the rear of the bike feel too firn and twitchy. Running a tyre at a higher pressure gives the suspension more work to do, there being less compression damping at the tyre itself. Simply lower your compresion damping on the rear suspension to compensate for the harder tyre.

    The Bridgestone 010 was replaced with the improved 014 and that has now been replaced by the 016 although 014s are available "while stocks last". There are of course several other tyre manufacturers who can supply a fitment suitable for the ZRX.

    While on the subject of tyres, althougth it is possible to fit a 180 section rear tyre to the 1100 which was designed to accept a 170, tyre manufacturers universally and the membership here generally frown on the idea. A wider tyre fitted to a rim narrower than it was designed for cannot possibly perform as it was intended to and there may be a safety issue here too.

    The present OEM tyre for the ZRX1200R and S models is the BT-020 with various options. This is an excellent tyre for general use being stable and relatively grippy - indeed did his first Rex trackday on the 020 and the bike was fine - and giving excellent tyre life.

    The 016 is being marketed as a replacement for the sportier 010, 012SS and 014 tyres but it's early days yet in terms of ZRXOC members using them.

    The 010 was a popular choice on the ZRX1100 and being grippier than the 020 has been used on ZRXOC trackdays to great effect.

    The 012SS was recommended as a very sporty choice but has a shorter life-span. It does compare very favourably on track with the 010, the latter tyres bobbling up very quickly whilst the 012SS stayed relatively unmarked for most of the sessions.


    Regular servicing and particularly oil/filter changes are a must. The debate still rages as to whether mineral or synthetic is preferred, the results will be in soon.


    "The Diamond Radiator Destroyer."
    If you still have a standard radiator cover on your ZRX you may find a little diamond shaped rubber pad sitting in the middle of it. If it's still there REMOVE IT IMMEDIATELY. This 50p item has been known to get grit trapped behind it and then rub a hole in the radiator core causing potentially very expensive damage.

    Things that come undone. - Nuts And Bolts.

    With proper servicing all safety critical items should be regularly shecked for tightness. We've had a couple of reported incidents where this has not been the case.
    Check the mounting bolts which secure the removeable section of the lower frame rail on the right hand side.
    Check the swingarm retaining nut/bolt for tightness. Both ends of this may look like frame plugs for decorative purposes but they are in fact the bolt and the retaining nut itself.
    Neither of the above bikes or riders were damaged in the above incidents but...........
    There may be other such incidents which have been omitted. If there is, let us know.

    Things that won't come undone when they should

    Many members have reported problems with the retaining pins for the rear brake caliper. Come time to change the rear pads these have been found to have corroded in place and all sorts of mechanical means have been used to remove them.
    This can easily be avoided;
    From the factory these pins have no lubrication or protection and due to their location (the caliper is below the swingarm and can get plastered in all sorts of muck) can and will corrode easily.
    No harm will come of periodically removing these pins and using a little copper grease or similar to protect them. (don't be tempted to simply spray WD40 in this area due to risk of contamination of discs and pads)

    The front suspension compression adjusters on the lower fork legs can suffer a similar fate and on pre '04 models if these sieze up, replacement of the entire lower fork leg is the only cure. () The adjustment screws are NOT removeable so don't try or you'll break something. ( see above).
    Because of an 'o ring seal in this mechanism, adding extra lubrication is fairly pointless as it's unlikely to penetrate. The best you can do is to keep this area clean and more importantly, keep the screws moving!
    Every once in a while, turn the screws fully in and out a couple of times. It'll pay you to make a note of your start position so that you don't upset your suspension settings for later. Do this by counting the clicks (or turns if no click is heard or felt) from the start position to fully screwed in (clockwise) Reset them to this position afterwards.

    Top hose wearing through.
    I think this applies mainly to the 1200 version; but a few members have had problems with the top radiator hose chafing against the bolt heads on the cyl head.

    Total headlamp failure on the S model.

    There is a fuse holder seperate from the main fuse box fixed to the RH frame rail under the seat, this is the main feed to relays operating the lights, it not unknown for the female part of the holder to become dislodged and not make proper contact with the male part of the fuse, leaving you with no lights.


    Torque settings

    Torque settings for the 1200 can be found here. There is no reason to believe that the 1100 settings should be any different.

    Oil and filter change.

    For the sake of about 3 for the filter and 0.3L of oil it's a false economy not to change the oil filter at the same time as the oil.

    There's little point in listing the whole step by step routine but a few pointers can make the job so much simpler.
    Ideally you need the bike supported upright. A rear paddock stand comes in handy for this. A front stand would also be an advantage as it'll hold the bike near enough level too. This is useful when checking the oil level when the job is complete. Warm the engine to operating temperature and then switch it off.
    The drain plug is at the bottom of that lumpy thing underneath the engine (A).
    The locating bolt for the filter is behind it and to the right. (B)

    This is the clever, time saving bit;

    Hopefully there should be no need to disturb the exhaust mounting near this provided that the locating bolt can be withdrawn while holding the cover in place. If this works then the cover can then be slid sideways away from the exhaust mounting and the filter itself will fall out easily. Sometimes the bolt and cover get corroded together or have been manufactured to such close limits that loosening the exhaust mounting is the only way to gain access to the filter. (If you can sort this out now while you have the parts in your hands, you'll make the next filter change easier for yourself. The bolt and cover should be two seperate parts.)

    Torque settings for both bolts are the same at 20N-m (2.0 kg-m. 14.5 ft-lb)

    (Don't forget to re-fit the drain plug before re-filling with fresh oil and don't ask which Rexer learnt this tip the hard/embarrasing way in his spotty youth. )

    Mineral, semi or fully synthetic oil? Not too important so long as it's the correct grade (10W-40)
    3.0L capacity when filter is removed.


    The possibilities of modding the standard ZRX are seemingly endless and as with any other bike fall into two distinct categories; Mechanical or performance mods and "shiny bits". There is a wealth of aftermaket goodies for the ZRX out there and no shortage of suppliers willing to relieve you of your "hard earned " in exchange for them.

    We'll ignore cosmetic mods for the moment as these are largely down to personal taste.


    Popular mods include replacement full exhaust systems, Akrapovic being the favourite, along with a Dynojet and proper re-jetting. This is generally accepted as being the best way to release a few extra HP from the ZRX (The OE headers and downpipes are quite restrictive). A replacement can on its own will not do a lot performance wise but at least allows the ZRX to sound like a proper motorbike. Popular end cans are available from Akrapovic, Art and Scorpion.

    Increasing the size of the rear sprocket by one or two teeth (i.e. 45 to 47 teeth on the 1100, 42 to 44 teeth on the 1200) won't give you any more power but makes that available more useful.
    Theoreticaly this will lower your top speed but in practice, mainly due to the effects of wind resistance it will be unaffected. Accelleration will however be dramatically improved.
    This mod can be done without having to alter the chain length in any way but, please note that if changing to a larger rear sprocket at the same time as replacing the chain and front sprocket you will be left with very little freeplay and chain adjustment. This in itself is not a problem as, with the eccentric chain adjuster in the forward position like this, the wheelbase will be shortened and the ride height increased. This will help the bike turn in quicker. (two mods for the price of one?)
    On a new machine this could possibly give Kawasaki UK a "get out clause" for any subsequent warranty claims in this area. Both the 1100 and 1200 models specify 110 link chain length. If when increasing the size of the rear sprocket by 2 teeth a longer 112 link chain is fitted this should put the eccentrics back to roughly where they should be.
    Similar results can be achieved by reducing the size of the front sprocket by one tooth. This may appear to be the easier, cheaper option but in the long term your chain will wear faster leading to added expense. There is also an increased risk of the chain fouling with the swingarm.
    For anybody thinking of trying something really radical this Gearing Calculator may help you decide on sprocket sizes.

    Ignition advancer.
    There's no real gains in horsepower to be had (allegedly) but the throttle response will be sharper and smoother.
    The ZRX ignition timing is factory set at 2 degrees BTDC to cater for the inferior Japanese quality fuels .
    European and American fuels are of a higher quality and to make the most of them and therefore be more fuel efficient 4 deg. BTDC is recommended. If fuel is being burned more efficiently then there must be a slight increase in power and fuel economy.

    A lot of people find the stock seat uncomfortable for long journeys, after market seats are available from Corbin and Sargent, or you can have your OE seat base modified by people like P&P seating amongst others.

    Although the sidestand isn't a weak point as such, it's been known to let the ZRX down quickly and expensively.
    The sidestand doesn't really move forwards quite far enough when it's down and it doesn't take much effort/lack of care to have the bike roll forwards slightly and the sidestand retract all by itself. If you happen to be standing on the wrong side of the bike at the time...........
    A quick fix is to remove up to 3mm of metal from the stop which the sidestand butts up against when down, with the result that the stand will be up to 2" (50mm) further forwards, requiring more effort/lack of care to have an accident with it.
    Taking a hacksaw/file/angle grinder to your new ZRX may sound a bit drastic but several people have allowed it to fall over first and then modified the sidestand later.


    Suspension Setup

    The standard suspension settings from the factory, also printed in the owners manual are a compromise designed to suit the majority of riders. Many of us have found these just too firm but have no idea how to start adjusting the bike to suit themselves.
    What follows isn't in any way THE definitive guide (if there is such a thing) but many of us have used these settings with posetive results.
    Origionally borrowed from ZRXOA

    Well being pretty deeply involved in the suspension game for the last year, since I started teaching free motorcycle suspension seminars here in the San Francisco Bay Area, I've had a lot of experience with helping people optimize their own bikes. Much of my experience on suspension setup has come firsthand, during my roadracing efforts that have spanned the last nine years.
    The one issue that should always be noted up front, when passing on suspension settings from one person's bike to another, is that the weight of the rider is a big variable in determining the "ideal" settings. In other words, what works for a 160lb. rider, will not work verbatim for a 200lb. Rider, despite being the same bike. I'll share with you my settings, but again take into consideration that my body weight is about 175lbs., so at least the shock and fork "preload" settings will have to be adjusted up or down, according to your differential of weight from that baseline. I suspect that the "compression" and "rebound" settings I've mentioned will be pretty close to a perfect starting point, regardless of your weight.
    SHOCKS: Compression: "2" setting / Rebound: "IIII" setting/ Preload 2nd softest ramp setting (this Preload was based on achieving 1" of measured "rider sag", with my 175 lbs. aboard. If you weigh more or less, go stiffer or softer accordingly: about 25 lbs. = 1 step position change)
    FORKS: Compression: "MINIMUM" (fully counter-clockwise) / Rebound: 1 click out from "Maximum" (fully clockwise till lightly seated, then one click out) / Preload: 4 lines showing (1.5" of measured "rider sag", again with my 175 lbs. Aboard ... adjust up or down from there, based upon your own weight difference: each 25 lbs difference = 1 additional line up or down)
    These settings, especially reducing the front fork "compression" to minimum, and nearly maxing out the"rebound", really transformed the bike's handling! The "knock the fillings out of the teeth" feeling, that I felt on my first ride with the factory settings, has now disappeared.For two up riding I add another 2 notches of preload on the rear and up the compression damping by 1 mark, and on the front, increase the preload by one ring on each fork leg (two full turns)

    Flipped Eccentrics
    Both the 1100 and 1200 are fitted with eccentric chain adjusters. In standard form the wheel spindle is held at the top of the eccentric with the bike sitting as low as possible. By loosening the clamp bolts, it is possible to raise the rear of the bike by rotating the eccentrics by approximately 180 degrees. Raising the rear of the bike in this manner alters the steering geometry slightly and many members have reported a faster turn in without sacrificing any straight line stability.[hr]

    If you are new to this site, then on behalf of the ZRXOC, welcome. The above is just a very brief insight into the wealth of knowledge gained by the membership of this site. Sign up for membership and complete at least 20 posts and you will be granted access to "Pitstop", our library, where the above subjects and a great many others are outlined in far greater detail.
    Have fun, Stay safe!
    Last edited by RHM; 24th April 2008 at 08:24 AM. Reason: A few bits about tyres
    Admin: ZRX-UK
    ...........You never can tell

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  2. #2
    Join Date
    Sep 2009
    Richmond, VA USA

    Re: Zrx1100/1200 Faq

    Thanks for the tips, going to check out the radiator tomorrow. And change the oil / filter. Plus source some swingarm spools from the race bin, and sliders....and grips...and....and...maybe even go for a Ride ! Heck Yeah !

  3. #3
    Join Date
    Sep 2009
    Worthing Sussex

    Re: Zrx1100/1200 Faq

    This is great really usefull. Thanks

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