Minor reengineering of Jim G’s 2017 ZX-14R for Weight, Ergos, Acceleration, & Handling
Summary:
Kawasaki did a lot of things generally well in designing and building the ZX-14R, including making lots of power across a very wide powerband, providing great aerodynamics, packaging a lot into a relatively (not literally) small and dense 3D space, focusing on mass centralization, and moving as much weight forward as they could (essential for 190 mph speeds).
But, there were also some design decisions, compromises, or missteps that created issues for at least some owners.
This posting describes the issues that affect ME personally, and the steps I have taken, or plan to take, to address them. And, in the process, it illustrates et again how a large enough number of small changes can make an overall big change.
I've included a number of photos at the end of the thread.
Inherent issues within the ZX-14R as designed & built by Kawasaki:
The bike is too heavy to be as “sporty” as I like: 592 lb with a full fuel tank is a notable handicap for a sporty bike.
The extra weight beyond that of a “normal supersport” bike also hurts acceleration, although that is a bit academic since the bike is already the quickest off-the-showroom-floor motorcycle missile you can buy in terms of quarter mile statistics.
There are heavy components that are located in a way that hurts on-the-road handling (adverse center of gravity effects). For example:
- The mufflers are very heavy and are located both high and wide
- The engine is very smooth, and yet Kawasaki chose to put 2 heavy bar ends weighing a total of 1.4 lb, and they are located 15 inches outboard of the bikes’ centerline and at close to the highest elevation on the bike.
- The bike wheelies too easily under high throttle, restricting the usability of the power, and putting 32 lb of OEM mufflers right above the rear axle causes wheelies to be quicker and higher.
There are heavy components that are located in a way that makes low speed maneuvering and walking of the bike more difficult (again, adverse center of gravity effects): Those high and wide mufflers are a prime example. When you try to walk the bike in a driveway, parking lot, or garage, they are like outriggers just WAITING for the opportunity to help tip the bike over.
The above weight and center of gravity issues are partially caused by the unique needs of componentry needed to cool, brake, and handle the drive forces of an over 200hp motorcycle, but they are also unintentionally made bigger by some of the choices that Kawasaki made:
- Example: If you need BIG and HEAVY mufflers to meet new European sound standards, at least mount them LOW versus high! By running them lower (like a Harley), Kawasaki could have not only reduced the “top heavy” feel of the bike, they could also have tucked them in closer, since all the moving suspension parts would then be ABOVE the mufflers versus below them. Plus, a lower mounting would also reduce the wheelie problem.
The seat is wide enough and high enough to create stability issues for a rider with a short inseam: The seat is very comfortable – more like a touring seat than a sportbike seat. It achieves the comfort by being both wide and thick. However, being wide and thick creates issues too:
- The thickness of the seat raises the distance from pavement to top of seat, making it 30.5”, which creates challenges for people (like me) who have a 29” inseam
- The generous width of the seat makes it even harder for a short inseam person to get his/her feet reliably on the pavement at a stop, especially if the surface is side-sloped at all (which most streets and roads are), or not a solid surface (e.g. gravel, mud, grass).
The combination of long reach to the non-adjustable bars and the positioning of the non-adjustable OEM footpegs notably accentuates the above short inseam issue because:
- The long reach (even for me with 34” shirt sleeve size!) forces the rider forward on the seat – no “choices” of sitting position on the seat
- But, that puts the rider’s legs right where the footpegs are, so he/she is forced to tilt his/her legs forward to get past the footpegs. This makes the reach to the ground even longer than it already was.
The bike is physically large enough to make a center stand very desirable, because:
- Access to the chain for routine lubrication and cleaning is very adversely affected by the size and positioning of those huge OEM mufflers
- “Rolling” the bike to gain access (past the humongous mufflers) to about 6” of chain at a time gets old very quickly, especially when you would need to do it daily when touring
- I can’t imagine how you could safely get the rear wheel off the bike on a highway or parking lot if you get a flat tire and a flatbed tow truck isn’t readily available.
Cleaning the bike is difficult because of the size and positioning of the mufflers, and the mufflers themselves are VERY difficult to properly clean and preserve, because of the very rough “asphalt-like” finish Kawasaki used on them (probably in an effort to keep them externally cooler)
Objectives:
With all the above in mind, my objectives on my minor re-design were easy to list:
1. Given the sheer number of times that the bazooka mufflers made an appearance above, it was obvious that objective number 1 had to be to replace them with mufflers that are either mounted a lot lower (some help) or a lot lighter, smaller, narrower, and able to be mounted more inboard. (more help than lower, if we need to choose from limited options).
2. Reduce the overall weight of the bike to the extent practical without spending way too much money or hurting the value of the bike.
3. Correct some of the Kawasaki decisions or compromises on mass centralization – get anything that is relatively heavy and significantly off the center of gravity either off the bike entirely or lighten and reposition it.
4. Make the bike safer and easier to handle at low speeds and when stopped by making it easier to get both feet flat on the ground.
5. For the reasons stated easier, get a center stand on the bike – a permanent one, not a shop one, so that it is there “all the time”.
6. Make the bike easier to clean by improving access to individual areas and components.
What I have done so far:
NOTE: If some of the following changes seem “small” in magnitude or effect, don’t dismiss them as being not worthwhile. You’ll see they add up to a notable total impact. The impact is nowhere near what “Rook” on this forum has achieved (80 lb weight reduction!), but I have reasons for being less aggressive than Rook has been!
Toolkit:
I removed the OEM toolkit, because it is unlikely to be needed on my brand new bike, it has limited usefulness anyway, it weighs 1.3 lb, and it is located WAY high and WAY back of the center of gravity (“COG” hereafter).
Center Stand:
I installed the center stand available from Kawasaki as an accessory. Yes, the center stand ADDS weight (5.06 lb), but you have to remove the lower rear undercowl to mount it which takes off 1.54 lb, leaving a “net” weight increase of only 3.5. lb. In addition, this 3.5 lb is (a) very close to the COG, and (b) mounted very low.
Seat Fairing:
I removed the passenger seat fairing, which weighs 1.17 lb, whose removal does not adversely affect the appearance of the bike, and which was located high and far back from the COG – exactly what you do not want.
Rear Fender:
I did a rear fender eliminator / tidy tail conversion. I removed the 1.62 lb rear fender / lic plate mount / Lic plate light assembly, and replaced it with a lighter (0.95 lb) and much shorter “Barbaren” (Chinese) kit from Amazon. This not only dropped 0.67 lb, but it also shortened the distance of that weight from the COG. It also gave me an LED versus incandescent lightbulb as the license plate light.
Footpegs:
I replaced the OEM footpegs (0.7 lb) with a set of adjustable Chinese billet footpegs (0.6 lb). The tiny weight saving (0.1 lb) is of course welcome, but the objective here was to enable me to move the footpegs rearward so that I don’t have to tilt my legs forward to clear them when the bike is at a stop. Later in this listing you’ll see that a change of exhaust system also enabled me to optimize the footpeg location MUCH better than with the OEM exhaust. In addition, these offset footpegs are (a) billet aluminum and (b) gorgeous, while also being remarkably inexpensive.
Seat:
I had a local custom car upholstery shop scoop out 1.5 inches of the foam from the driver portion (only) of the seat. This dropped its weight by 6.90 – 6.61 = 0.29 lb, but much more importantly made it notably easier for me to get both feet flat onto the ground, and yet did not make the seat at all uncomfortable, because it was SO thick to begin with.
Note also that lowering the seat lowers the actual COG of the COMBINATION of rider plus motorcycle. This improves handling and also raises the amount of power that can be applied before the bike wheelies. (This is why dragracers have seats that are as low as possible).
Finally, the lowering job was done subtly enough that you would have to see my ZX-14R right beside another one with an unmodified seat to “know” that mine has been lowered. It does not “look” lowered. (See the profile bike photos below)
Battery:
The OEM Battery was a 12V 12AH Furukawa FTX14-BS (=Yuasa YTX14-BS) with a CCA (cold cranking amps) rating of 200. Its reported weight per Furukawa was 10.1 lb. But my actual battery was a Yuasa YTX14-BS because the dealership replaced the Furukawa after we discovered that it had been permanently weakened by sitting at the dealership, charged, after prep had been done on the bike, for about a year (I bought a brand new 2017 in January of 2019). The Yuasa weighed an actual 10.27 lb.
I replaced the 10.27 lb / 200CCA Yuasa battery with a Shorai (Lithium) LFX19A4-BS12
With a CCA = 285 (43% better) and weight = 2.5 lb, for a weight saving = 7.77 lb!
The Shorai is the same length and width, and has the same terminal orientation as the OEM battery, but is considerably shorter in height. I COULD have altered the battery tray “tiedown strap” setup on the bike to take advantage of this to lower the COG, but that would have made it impossible to safely secure an OEM size battery in the future, if I ever needed an emergency on the road battery replacement where no Lithium battery was available locally. So I instead built up the height of the Shorai via the self-sticking foam pieces that Shorai provides for that purpose.
As you will later see, the Shorai battery is the 2nd largest individual weight reduction, after the slip-on exhaust. Note though that this weight reduction has less effect on this bike than it would on many others because of its location.
On most sportbikes, the battery is located high and rearward, which means that when you get a lighter battery, you improve acceleration, handling, and center of gravity. However, the battery on the ZX-14R is located right near the center of gravity, just behind the engine and halfway down the monocoque backbone frame. So, you get the handling and acceleration benefits, but don’t really enhance the COG. Rook on this forum discovered this himself earlier.
Exhaust:
I finally found a British slip-on exhaust system that weighs far less than the OEM, has WAY better size and location for COG purposes, gives a few more horsepower, is remarkably quiet, looks MUCH better, is fully compatible with the center stand (even comes with a rubber bumper for the center stand), and was a bargain thanks to Brexit.
The entire OEM exhaust weighs just over 41 lb, making it a tempting weight reduction target, i.e. replace it with a “full” aftermarket exhaust system. But I did not want to do that much work, spend that much money, and have to get either an ECU tune or a Power Commander to keep the AFR safe. Besides, if you examine the ZX-14R header system, you will see that there is really not much potential for lighter weight there unless you go Titanium.
But the ZX-14R OEM mufflers alone (Mufflers with welded on 54mm piping, heat shields and cosmetic cover parts, and hardware) actually weigh 31.9 lb on my digital scale.
Graves makes a really nice Kawasaki ZX-14R Carbon Fiber Catback Slip-on exhaust that weighs just 8.6lbs, for a weight saving of 23.3 lb. And, I have had great results with 3 other Graves systems in terms of performance, quality, durability, and power. But, Graves did not address center stand compatibility when they designed the ZX-14R system, are unable to assure me that it will fit with the center stand, and are so busy that they cannot even determine compatibility until at least some time in April.
Delkevic is a British company that makes relatively moderately priced exhaust systems that most buyers rate very highly. Plus, the current Brexit crisis in The United Kingdom has depressed the value of the British pound, making Delkevic systems an even better buy.
Delkevic offers a number of ZX-14R kits, but I like KIT 0869, which includes Twin 18" Carbon Fiber oval mufflers (their longest available mufflers), stainless steel 54mm piping, and all required clamps, in a VERY easy to install kit.
The Delkevik website weight information is incomplete – it provides the muffler weights (including clamps), but it does not give the weights of the left and right muffler pipes and forward clamps that join the mufflers to the OEM exhaust. After receiving the system, I weighed all the pieces and got a total of 12.16 lb.
This means that the Delkevic system provides a 19.74 lb weight saving.
This is not quite as good a weight saving as the graves system provides, but given the circumstance noted above with the graves system, and given the immediate availability and bargain price of the Delkevic system, and the very nice quality of it, It made sense for me to go that way.
Look at the photos I have attached below, and especially the mix-and-match photo that shows one OEM muffler still on one side of the bike, and a Delkevic muffler installed on the other side. I think you will see why this system is so advantageous given my specific objectives:
- It’s fully compatible with the center stand
- It saves 19.74 lb
- It makes 5.4 more peak rwhp, and as much as 8 more rwhp at mid-rpm
- It requires no ECU retune or Power Commander to do it
- It dramatically narrows the bike
- It dramatically improves the COG via BOTH weight reduction and narrowness
- It’s relatively quiet: 96 to 98db with easy in & out baffles, and 98-100 without
- It sounds good to my ears
- It makes chain maintenance a LOT easier
- It makes cleaning the bike a lot easier because the mufflers are smaller allowing better and far easier access to other components needing cleaning
- The carbon fiber canisters themselves are way easier to clean than the OEM “asphalt coat”
- It reduces the bike’s urge to wheelie by taking that 29.74 b off of its high and rearward location above and behind the rear axle
- It looks WAY better than the bazooka OEM mufflers
- The carbon fiber mufflers are cool to the touch immediately after a ride, enabling me to place the dust cover on the bike right away.
Sidestand:
I also replaced the OEM sidestand. The OEM sidestand is steel, looks spindly, can easily corrode because its base rests on the ground most of the time, and weighs 1.15 lb. The aftermarket Chinese CNC machined billet aluminum sidestand I found supports the side stand safety switch functionality, won’t corrode, looks tough, and was very reasonably priced. It has a threaded hole into which you thread an M5 – 1.0 x 30mm bolt (you supply the bolt) to act as the “pin” that activates the safety switch fork. This sidestand weighs just 0.70 lb, including the added bolt. So, I dropped 0.45 lb of weight.
Bar Ends / Sliders:
Replacement bar ends are on the way to me. The OEM bar ends weigh 0.70lb each x 2 bar ends = 1.40 lb. I have conflicting weight claims on the Shogun UHMW (slippery durable plastic)bar ends / sliders that I have on order. They apparently weigh either 0.15 lb or 0.25 lb. So, the weight saving is either 1.15 lb or 1.25 lb.
This weight saving is small but since the bar ends are 30” apart, with each being 15” off the centerline of the bike, they have a measurable effect on COG . (This is why Olympic ice skaters always pull their arms in as tightly as possible to their bodies to execute a spin). The OEM bar grips don’t weigh that much in the overall picture, but every little bit helps.
Rear Sprocket:
I have a replacement rear sprocket in hand ready to install. The OEM 42 tooth rear sprocket is steel and weighs 984 grams = 2.17 lb. A number of Vortex, Renthal, and Driven sprockets weigh between 1.0 and 1.17 lb. But I went with a Driven 7075 hardened aluminum because of past good experience with a Driven lightweight sprocket on a different bike. This will give me a weight saving = 1.0 lb when I get it installed. That will only happen though when I am ready to also replace the tires or do some other rear wheel work, as I don’t have the facilities to do a wheel removal and replacement (I live in a condo) and must pay the local shop to do that. At that point, the sprocket swap becomes just a relatively quick add-on job for the shop.
The 1.0 lb reduction contributes to overall weight reduction and COG improvement, but more significantly it is a rotating component in the driveline, and the 1.0 lb reduction will greatly reduce its rotational moment of inertia (MOI). The effect of reduced MOI is well documented as having several times the impact of static weight reductions.
Tires:
When the OEM tires are worn out, I will be replacing them with lightweight tires. The total weight of both OEM tires = 24 lb. The replacement tires will be Pirelli Diablo Rosso Corsa tires, with the rear tire weight = 12.85 lb and the front tire weight = 9.00 lb, for a total of 21.85 lb. This makes a weight saving = 2.15 lb.
Like the rear sprocket the bigger deal here, beyond the individual contribution to static weight reduction, is the reduced rotational moment of inertia. And of course the Pirelli Diablo Rossi Corsa tires are very high performance tires.
Helibars Risers:
I’m going to ADD weight, but improve ergonomics and pavement footing by installing a pair of Helibars Risers that are enroute to me from one of our other forum members. I have been unable to get the weight of these, even from the sellers who sell them, but the weight of the entire packaged shipment to me shows as 0.34kg = 0.75 lb.
The reason for installing these is to further stabilize my feet when the bike is standing still on pavement. You might wonder how they do that, so here’s the explanation: Right now, the combination of lean angle and reach to the bars is causing me to “ride the back of the fuel tank”, which is fine when actually moving down the road, but makes it harder for me to place my legs and feet ideally for best stability on the ground when stopped – I’m pulled upward just a bit in order to reach the bars.
The Helibars will move the clip-on bars upward about ¾” and rearward about 1/2", which will, based on past experience, have a pretty notable favourable effect on my ability to get my feet down on the ground. It is not possible to go even higher or more rearward with the bars without issues due to bar interference with fairing and fuel tank cover, and wiring and hydraulic line length and routing issues. But on most motorcycles, fractions of an inch get the job done.
Adjustable Gearshift Lever (If needed):
I am going to try the new footpeg positions for a while to see how well they work. If I find that I want even more rearward pegs, I’ll likely then need a longer gearshift pedal so that I can maintain ideal peg-to-pedal distance. If so, I have found an aftermarket adjustable, lightweight shifter pedal that should work. The OEM non-adjustable shifter pedal weight = 0.14lb. The Yana Shiki A4209 Polished Adjustable Shifter Pedal for the ZX-14R = 91g = 0.2 lb, so the weight penalty would be only 0.06 lb.
Tabular summary of the overall plan:
The table below shows my progress to-date on the overall plan as it currently exists (It gets updated as I find more or better solutions!). Note that already I have taken 27.8 lb off the bike, and have planned for at least 4.4 more lb. of weight reduction. So, a current goal of at least 32.2 lb net reduction. This is the “net”after taking the adverse hit of the 3.5 lb for the center stand, so it’s a pretty good effort.
How well does this all work together?
VERY well! My first test ride with only the changes already actually made (ending with the sidestand) was very satisfying.
First of all, I was preoccupied with getting through my normal pre-ride checklist and so never even thought of bracing myself for a louder exhaust. Turns out there was no need. I know that realistically the Delkevic exhaust is surely louder than the OEM exhaust, but if there’s a difference, I was “unaware of it”.
During the ride, the exhaust was audible but barely more so than the OEM exhaust. Given how quiet it was on this test ride, I will likely try removing the easily removed and replaced baffles to hear how the sound changes in volume and characteristics.
I cannot sensibly comment on power curve changes, as the bike has only about 200 miles on it, so the engine is still in break-in.
The changes made to improve my ability to reach the ground more easily and confidently really, really worked. That 1.5” drop in seat height coupled with the rearward movement of the footpegs made all the difference. I am more comfortable, more confident, and safer at stops now.
The bike’s handling is notably better. It’s amazing what taking just 28 b. off a bike does for its agility at all speeds, and its stability at low speeds and in tight low speed turns.180 degree turns at the local motorcycle shop’s tight parking area were no issue.
Dismounted handling of the bike at walking speeds in the garage is better, but still no piece of cake, due to the sheer height of the COG. The only way to easily lower it further now is to not keep the fuel tank full, but that introduces other issues I want to avoid. So, I guess this is as good as dismounted handling of this bike is realistically going to get. (It’s no Harley. My 735 lb, but LOW Harley Breakout was notably easier to push around)
First ride impressions on the length of the gear shift lever are that it works with the footpeg moved 30mm rearward, but it’s not ideal. So, I think I will probably order that adjustable gearshift lever.
The center stand is indeed a real blessing. It makes chain maintenance and bike cleaning, at home or anywhere else it might be needed, MUCH easier and faster too. The 3.5 lb weight penalty seems worth it to me, especially since the center stand is located so low on the bike and thus reduces, not makes worse, the COG location.
Cleaning the bike is very notably easier now due to the combination of smaller mufflers, center stand, and easier-to-maintain muffler finish.
Finally, the first thing any of my friends, and my dealer, have said on seeing the bike with the changes, is “Wow, that looks MUCH better”.
But if you are detail oriented, you might have noticed in the tabular summary that of the 28 lb taken off, almost 20 lb came off the REAR end of the bike. This is a bonus that I had not picked up in my planning. It is a very nice outcome as it further moves the COG forward, enhancing stability at speed. It should also somewhat reduce the bike's eagerness to wheelie. This is now the very first motorcycle I have ever encountered where the weight on the front wheel is actually higher than the weight on the rear wheel, before rider (THis is why the recommended tire pressures are 42 psi at BOTH front and rear). The rider of course moves the weight distribution rearward when he or she gets on the bike. A stock 2017 ZX-14R has 3 more lb. on the front wheel than the rear, and mine now has 23 more lb on the front than the rear.
Summary:
This all works! All my objectives have been addressed, and the only further changes that I see as short-term goals are to get the adjustable gearshift lever, and to continue to seek improvements that would make the bike less top heavy.
This has been a good first project on this bike.
Jim G
Photos:
Before the exhaust change:
After the exhaust change:
The OEM "widebody" look:
OEM width versus Delkevic width:
Width after Delkevic installation:
Billet sidestand and offset pegs:
* Last updated by: JimGnitecki on 3/7/2019 @ 4:05 PM *