2025 Kawasaki KX450SR
First Impression
Story by Scott Hoffman and Trevor Hunter, Photos by Scott Hoffman, Mark Kariya
Is the new Kawasaki KX450SR the bike all green machine enthusiasts have been chomping at the bit for? First off, if you waited or have been riding a fairly stock 2024 or 2025 standard KX450, you will be fully impressed with the SR. All of the weaknesses some of the media have pointed out regarding a stocker are in the rearview mirror, the SR is a pure ripper from the bottom end to the “WOW” mid and top-end pull.
From the standard 2025 KX450, Kawasaki really leaned on the right parts while crafting the new SR. Yes, its $13,599 sticker price might sting a little but you really do get a fairly hefty bang for your buck, especially if comparing the list price of a stock KX ($10,499, even though few pay this price) and what it would run to build a ride with similar SR upgrades. We estimated retail value of the upgrades is over $5,500 depending on how you calculate prices and if labor is considered. So, what is the SR (Special Racer) all about?
-Showa special coatings on the fork (Kashima upper and super-hard titanium on the lower legs)
-Upgraded valving settings, slightly firmer over a standard KX
-Outer shock body is Kashima coated
-SR spec X-Trig ROCS-TECH triple clamp and handlebar mounts
-Special SR spec Pro Circuit Titanium exhaust
-Polished Intake Ports
-Fine-Tuned ECU settings (SR and SR Aggressive)
-Metallic Magnesium Gold valve cover
-DID Dirt Start ST-X rims
-Renthal Sprocket
-DID Gold Chain
-Hinson Clutch Cover
-SR Factory-inspired graphics
And we did discover if you did want to try to build an exact SR replica, the PC exhaust is not standard but is an SR spec and only available through a Kawasaki dealer. Same goes for the X-Trig clamps, the two have different mounting systems (SR has a standard KX-style castle nut for the bearing tension and a top bolt, while aftermarket (adjustable offset) X-Trig has the race team style with a main nut and a pinch bolt that clamps onto the steering stem). This clamp is fixed at 23mm offset, same as the standard KX. The ECU is unique to the Kawasaki SR, yet still tunable via the Rideology App.
Something to note – you can buy the XTRIG Triple Clamps that come standard on the SR as a Kawasaki part number for a fair amount cheaper than what they’d cost normally. On Rocky Mountain ATV/MC under OEM parts, the clamps sell for $527.06 (Part # 99969-3880) and the PHDS Bar Mounts sell for $170.25 (Part # 99969-3881). You can support DBT by clicking through HERE to purchase at RMATVMC.
Unlike a standard KX450, there is the base SR map (light off) and there is map two (light on) which is a more aggressive map. On a standard KX, map two (light on) is a more mellow map. Traction control still has two settings and there is also launch control setting for starts.
Right from the showroom, the SR looks trick—it better since it costs more. Yet is the juice worth the squeeze? After a few laps at Glen Helen for a one-day impression on a day that did not offer the best track conditions, both our younger and faster rider, as well as our washed-up vet, both commended the KX and wanted more time on the SR. First and foremost, the power is there, and there is a lot of it. Our younger lad uttered “the SR is Yamaha YZ450F fast.” The delivery is ultra broad with really good bottom and a monster mid and top-end pull compared to the standard KX450. Also be aware, there were no airbox mods like many riders have made to help their KX breathe better on their 2024-2025 KX450. Kawasaki did update the air filter for 2025 to a rounder filter with slightly more surface area, but that is about it.
We did not have time to use the Rideology App to make any changes but we don’t think we needed to, yet it would have been nice to see what power character we could alter with the App. It’s pretty amazing that polished intake ports, tuned PC exhaust, and optimized ECU settings alone could transform this engine to the SR. We have seen similar gains with aftermarket ECU, exhaust, and airbox mods but not as refined of a delivery across the board. It’s an SR for a reason but similar gains to the standard KX could have earned Kawasaki a few shootout wins.
We really like the changes to the map switch as well. The base SR map is standard and then light on is even more aggressive. Our vet rider liked the standard setting with mild traction control on but our faster rider really liked the more aggressive map with full traction control on.
No matter how you slice up the options, the SR out of the box is much improved in a really good way over bone-stock KX. This is the bike everyone with a standard 24-25 KX wants to achieve. The SR just comes alive and the delivery is exciting but still very fun and manageable. Want more, twist your wrist further. Want less, less twist and traction control or jump into the App and make changes. The SR delivers if you are looking for more oomph.
As for the chassis, the ergos are the same, the handling is full KX450. The suspension has a similar feel but the fork does have improved action over a non-SR. It just holds up in the stroke a little better, improved bottoming control but might be still a little under-sprung for faster or heavier riders heading into that 200lb range. Both our test riders felt more comfortable as the track got rougher by going in on the standard compression settings. As for the shock, minor clicker changes were done depending on rider preference. Standard rider sag is still at 104mm but we did notice that the standard SR fork height is flush with the X-Trig clamps over 5mm exposed on the standard KX450.
Our faster rider was struggling with some front end stability early in the day under heavy loads coming down the hills and in the pockets between jump faces. The fork was simply getting too low in the stroke, so clicking in the compression 2-3 clicks worked wonders in remedying that issue. Likewise, the rear shock was a little too active and busy around the track, which led to us slowing down the rebound 2 clicks out back and helping settle the whole bike overall. With these two changes, we felt the bike was more balanced and
The SR feels a little more agile or easy to change direction over a standard KX, part in due to the X-Trig clamps and the updated fork settings, but also due to the more lively engine character. No big changes, but slight difference. The X-Trig bar mounts are a nicety and do add comfort for most riders who have tested them.
There is for sure a value in the updated items like the DID chain and Renthal sprocket. The SR setup will probably last twice as long as a standard KX. On our personal KX450, it did not take long for the stock chain to stretch and flap around before we swapped it out. And as for rims, it all depends on the rider. One of our test riders is known for making flat spots in rims after a short period, so the stronger ST-X rims are a nice upgrade if you are hard on wheels. The big ticket items offer the lion’s share of the value and items like the polished ports and suspension valving are not simple bolt-on items.
As good as the SR was, there are a few simple things we would want to try that could improve it even further. Small things like using the soft elastomers in the XTRIG PHDS bar mounts and a longer chain to get the axle further back in the swingarm could improve comfort and stability even more so and put the icing on the cake. Also, Dunlop’s MX34 tires aren’t our preferred tire of choice, especially up front, and swapping to Dunlop’s AT82’s or another tire could bring round out a more familar and comfortable package. We could get really greedy and try throwing an 18-in rear wheel and IMS tank on to see how it’d work off-road?!
Impression:
After just over three hours on the SR with a fast rider and let’s just say a seasoned vet (slower), both were delighted with what the SR offered and were impressed with how rideable the added boost the engine package now delivers. We just wonder if it would be even faster with airbox mods and some race fuel. If so, hold on even harder! We did ride our version of an SR we built to compare; they are similar, but our SR would cost way more than $13k to build if we priced everything out at retail prices. The 2025 KX450SR almost seemed a little more refined or dialed in over our ever-evolving ride, even though we just rode the real SR bone stock. Kawasaki for sure now offers a bike everyone with a standard KX wants to aspire to be. The SR is more of a limited-edition model so don’t expect dealers to be flooded with “Special Racers.” At the end of the day, we were bummed the SR was not going home in our truck. If you are a KX kind of rider, the SR will not disappoint, if you can find one available.
