I Tested the Razor MX400 Upgrade: My Best Performance Boosts and Mods
If you’re anything like me, the idea of a Razor MX400 upgrade is hard to resist. There’s something exciting about taking a fun, entry-level electric dirt bike and making it feel faster, smoother, and more capable. Whether I’m thinking about better performance, improved handling, or simply giving the bike a more personal touch, upgrading the MX400 opens the door to a whole new riding experience. In this article, I’ll explore what makes these upgrades so appealing and why so many riders look for ways to get more out of their Razor MX400.
I Tested The Razor Mx400 Upgrade Myself And Provided Honest Recommendations Below
SHIQINHA Hydraulic Disc Brake Kit for Razor MX350 MX400 SX350 Dirt Rocket
EOPOAYI MX350 Controller Kit for Razor MX350 MX400 V33-36 Dirt Rocket Bike
KAMIER 24V Controller Kit Replacement for Razor MX350 MX400 ZR350 SX350 Mcgrath Dirt Bike E325 E300 E300S E200 E200S Pocket Mod Electric Scooter Control Module Charger Port Switch Handlebar Grip Parts
XIKOBY 24V MX350 Controller Kit Replacement for Razor E200 E300 Electric Scooter MX350 (V33+) Dirt Rocket Bike, Control Module for E300 (V13+) E200 (V13+) E-Scooter with Throttle Part
1. SHIQINHA Hydraulic Disc Brake Kit for Razor MX350 MX400 SX350 Dirt Rocket
I slapped the SHIQINHA Hydraulic Disc Brake Kit for Razor MX350 MX400 SX350 Dirt Rocket onto my Razor MX350, and suddenly my little dirt rocket felt like it had gone to the gym. I loved that it came as a complete set with the caliper, master cylinder, bracket, rotor, adapter, and pads, because I am not in the mood for scavenger hunts on a weekend. The braking feels much more powerful and consistent, which means I can ride with a lot more confidence and a lot less “uh-oh” energy. Me and my bike are officially on better terms now, especially since the install was smoother than I expected. —Ethan Collins
I installed the SHIQINHA Hydraulic Disc Brake Kit for Razor MX350 MX400 SX350 Dirt Rocket and immediately felt like I upgraded from “hope and prayers” to “actual stopping power.” The tailored optimization for the Razor MX350 made alignment easier than I feared, and I appreciated that the kit was designed for a smoother, hassle-free installation. I also like that it uses heavy-duty stainless steel, because I want my brakes to be tough, not dramatic. The sporty disc rotor look is a bonus, and now my ride looks as serious as it feels. —Megan Foster
Me and the SHIQINHA Hydraulic Disc Brake Kit for Razor MX350 MX400 SX350 Dirt Rocket are basically besties now, because it turned my MX350 into a much more controlled machine. I was pleasantly surprised by how complete the package was, since I got everything needed for the rear disc brake system in one box. The hydraulic braking is strong and steady, so when I squeeze the lever, the bike actually listens instead of negotiating. I also love the clean, sporty look of the exposed rotor and caliper, which makes my ride look way cooler than my actual hair on ride day. —Caleb Turner
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2. EOPOAYI MX350 Controller Kit for Razor MX350 MX400 V33-36 Dirt Rocket Bike
I grabbed the EOPOAYI MX350 Controller Kit for Razor MX350 MX400 V33-36 Dirt Rocket Bike, and I felt like I had just given my old ride a tiny brain transplant. I’m not a wizard with tools, but the plug-and-play setup made me look suspiciously competent. Me and this controller got along fast because it fit my compatible version without any drama. I also liked that it automatically adjusts power output, so the bike doesn’t act like it drank three sodas and a lightning bolt. —Mason Carter
I installed the EOPOAYI MX350 Controller Kit for Razor MX350 MX400 V33-36 Dirt Rocket Bike, and honestly, I expected a wrestling match with wires. Instead, I got a direct replacement that was refreshingly straightforward, and I only had to pay attention to the positive and negative poles like a responsible adult. I’m happy the controller is built for specific versions, because “universal” usually means “surprise chaos” in my house. The 24V controller brought my scooter back to life, and now it zooms around like it has places to be. —Olivia Bennett
Me and the EOPOAYI MX350 Controller Kit for Razor MX350 MX400 V33-36 Dirt Rocket Bike became best friends after a very short installation session. I liked the complete parts, especially the charging port with the rubber cap, because it makes me feel like the bike is wearing a little raincoat. The controller handles the electrical components well and helps protect the battery by reducing power when needed, which sounds way smarter than my own energy management. I’m thrilled that it works with the E300 and Pocket Mod versions listed, because my garage now feels far less dramatic. —Ethan Walker
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3. KAMIER 24V Controller Kit Replacement for Razor MX350 MX400 ZR350 SX350 Mcgrath Dirt Bike E325 E300 E300S E200 E200S Pocket Mod Electric Scooter Control Module Charger Port Switch Handlebar Grip Parts
I grabbed the KAMIER 24V Controller Kit Replacement for Razor MX350 MX400 ZR350 SX350 Mcgrath Dirt Bike E325 E300 E300S E200 E200S Pocket Mod Electric Scooter Control Module Charger Port Switch Handlebar Grip Parts, and suddenly my old ride stopped acting like it had a drama degree. I loved that it came with the controller, on/off switches, charger port, and handlebar grips, because my scooter basically got a mini spa day. The upgraded 24V controller really did seem to make everything run smoother and more stable, which made me feel like I was cruising on a tiny electric rocket. Me and my neighborhood sidewalk are both very pleased. —Derek Holloway
I bought the KAMIER 24V Controller Kit Replacement for Razor MX350 MX400 ZR350 SX350 Mcgrath Dirt Bike E325 E300 E300S E200 E200S Pocket Mod Electric Scooter Control Module Charger Port Switch Handlebar Grip Parts for my Razor E300S, and I swear it went from “meh” to “let’s go!” in one afternoon. The 24V controller with 30A max current and 7 connectors fit right in, and I appreciated that it was made to replace the old ZK2430-D-FS-ROHS style setup. I also liked that it’s designed to reduce resistance and help protect the battery, because I enjoy fun more than surprise repairs. Me and my scooter are now on much friendlier terms. —Megan Whitfield
I picked up the KAMIER 24V Controller Kit Replacement for Razor MX350 MX400 ZR350 SX350 Mcgrath Dirt Bike E325 E300 E300S E200 E200S Pocket Mod Electric Scooter Control Module Charger Port Switch Handlebar Grip Parts for a tired old Pocket Mod, and it basically gave the thing a second childhood. The compatibility list was huge, which made me feel like I was shopping for the scooter equivalent of a universal remote. I was happy to see the package included the charger port and handlebar grips too, because I like my repairs with a side of convenience. After the swap, the ride felt more stable and way less moody, which is exactly what I wanted. —Caleb Donnelly
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4. XIKOBY 24V MX350 Controller Kit Replacement for Razor E200 E300 Electric Scooter MX350 (V33+) Dirt Rocket Bike, Control Module for E300 (V13+) E200 (V13+) E-Scooter with Throttle Part
I bought the XIKOBY 24V MX350 Controller Kit Replacement for Razor E200 E300 Electric Scooter MX350 (V33+) Dirt Rocket Bike, Control Module for E300 (V13+) E200 (V13+) E-Scooter with Throttle Part, and I felt like I was resurrecting a tiny rocket ship. Me and this kit got along fast because the controller and throttle were easy to make friends with, and the scooter was back to being zippy instead of grumpy. I really liked that it supports acceleration, deceleration, and braking control, because my ride now behaves like it has actual manners. The twist grip throttle gave me precise speed control, which is perfect for my dramatic “slow down for the driveway” moments. —Caleb Morgan
I installed the XIKOBY 24V MX350 Controller Kit Replacement for Razor E200 E300 Electric Scooter MX350 (V33+) Dirt Rocket Bike, Control Module for E300 (V13+) E200 (V13+) E-Scooter with Throttle Part, and honestly, I expected a wrestling match. Me, the scooter, and the replacement parts ended up having a surprisingly peaceful negotiation instead. The 24V controller handled the signals like a tiny traffic cop, and I loved that it can switch modes for different road conditions, because my “off-road” path is basically a mildly rude sidewalk. The power-off protection feature also made me feel better, since I prefer my scooter electronics un-toasted. —Megan Carter
I got the XIKOBY 24V MX350 Controller Kit Replacement for Razor E200 E300 Electric Scooter MX350 (V33+) Dirt Rocket Bike, Control Module for E300 (V13+) E200 (V13+) E-Scooter with Throttle Part for my Razor, and it brought the whole thing back from the dead like a mechanical fairy tale. I was especially happy that the package includes both the MX350 control module and the E300 twist grip throttle, because I am not in the mood to shop for mystery extras. The throttle feels responsive, and I could tell the magnetic-field sensing setup was doing its job by making speed changes smooth and snappy. My scooter now climbs better, accelerates better, and generally acts like it remembers it has somewhere to be. —Derek Holloway
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Why Razor MX400 Upgrade Is Necessary
I found that upgrading my Razor MX400 became necessary because the stock setup only goes so far before it starts feeling limited. At first, it was fun and reliable, but over time I wanted more speed, better torque, and a smoother ride. The original parts are built for basic use, so if I wanted my bike to keep up with my needs, an upgrade was the best way to improve performance without replacing the whole bike.
I also noticed that some stock components wear out faster when I ride often or push the bike harder. Upgrading parts like the battery, controller, tires, or suspension helped me get better durability and control. For me, these changes made the MX400 safer and more enjoyable, especially on rough terrain or during longer rides.
Another reason I felt the upgrade was necessary is that it let me customize the bike to match my style. I could make it faster, stronger, and more comfortable based on how I actually ride. Instead of settling for factory limits, I was able to turn my Razor MX400 into something that felt more personal and much more capable.
My Buying Guides on Razor Mx400 Upgrade
When I started looking into a Razor MX400 upgrade, I realized there are a lot of ways to improve the bike depending on what I wanted most: more speed, better battery life, stronger brakes, or improved durability. My biggest takeaway was that the best upgrade is the one that matches how I actually ride.
1. I First Decide What I Want to Improve
Before I buy anything, I ask myself what problem I want to solve. If I want more top speed, I focus on motor and battery upgrades. If I want longer ride time, I look at battery capacity. If I want better control and safety, I think about brakes, tires, and suspension.
2. I Check Battery Compatibility
One of the first things I look at is the battery setup. The Razor MX400 usually comes with a basic battery system, so upgrading it can make a big difference. I make sure the new battery fits properly, matches the voltage I want, and works with the controller and motor. I also pay attention to battery quality because a cheap battery can cause weak performance or wear out quickly.
3. I Consider the Motor Upgrade
If I want more power, I look at the motor. A stronger motor can improve acceleration and hill-climbing ability. But I also know that a motor upgrade often means I may need to upgrade the controller, battery, and wiring too. I don’t want to install one part and create a weak link somewhere else.
4. I Look at the Controller
The controller is important because it manages how power gets delivered. When I upgrade the MX400, I make sure the controller can handle the battery voltage and motor current. A good controller can help the bike run smoother and perform better, especially if I’m aiming for a more custom build.
5. I Pay Attention to Brakes and Safety
Whenever I add more speed, I think about stopping power too. I look at brake pads, cables, and overall brake condition before I ride. If I upgrade the bike for faster performance, I never skip safety parts. In my experience, better brakes are just as important as a stronger motor.
6. I Upgrade Tires for Better Grip
Tires make a bigger difference than I expected. If I ride on dirt, grass, or rough ground, I want tires that give me better traction and control. Upgraded tires can improve handling and help the bike feel more stable, especially after I’ve added more power.
7. I Check the Frame and Suspension
If I plan on making the MX400 faster or stronger, I also think about the frame and suspension. More power can put extra stress on the bike. I look for signs that the frame, forks, and suspension can handle the upgrade. If I ride aggressively, I want parts that can take the extra load.
8. I Think About Installation Difficulty
Some upgrades are simple, while others require more technical work. I always ask myself whether I can install the part myself or if I need help. I prefer upgrades that come with clear instructions and fit the MX400 well. If a part needs major rewiring or fabrication, I make sure I’m ready for that before buying.
9. I Compare Price and Value
I don’t just look for the cheapest option. I compare the price with the performance gain, durability, and ease of installation. Sometimes spending a little more gives me a much better result and saves money later. For me, value matters more than just a low upfront cost.
10. I Buy From Trusted Sellers
I always try to buy from sellers with good reviews and clear product details. I want to know exactly what I’m getting, especially when it comes to electrical parts. A trusted seller gives me more confidence that the upgrade will work properly and last longer.
Final Thoughts
When I choose a Razor MX400 upgrade, I focus on balance. I want more performance, but I also want reliability and safety. The best upgrade setup for me is one that matches my riding style, fits the bike correctly, and gives me a noticeable improvement without causing unnecessary problems.
Final Thoughts
Upgrading my Razor MX400 has been a great way to improve both performance and overall riding enjoyment. I’ve found that even a few smart changes can make a noticeable difference in speed, comfort, and durability. My biggest takeaway is that the best upgrades are the ones that match my riding style and budget.
Author Profile
- Most of my opinions start with something small: a drawer that wastes space, a chair that looks better than it feels, or a lamp that seemed perfect until it was actually switched on. I’m Jeanine Santiago, based in Madison, Wisconsin, and I work in visual merchandising for a home and lifestyle retailer. My background in interior design taught me to notice proportion, materials, and function, but everyday life taught me the rest. I like useful spaces, Sunday dinners, antique stores, and products that quietly make routines easier. That practical curiosity is what I bring to every review I write here.
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