I Tested the Razor MX400 Upgrade: Best Mods to Boost Speed, Power, and Performance
If you’re anything like me, the Razor MX400 is more than just a small dirt bike—it’s a starting point for fun, creativity, and hands-on upgrades. A Razor MX400 upgrade can completely change the way this ride feels, whether you’re looking for more speed, better handling, improved battery life, or just a more personalized setup. What makes this topic so interesting is how much potential the MX400 has once you start making changes, and how many riders enjoy turning a stock model into something that feels faster, tougher, and more exciting to ride.
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 grabbed the SHIQINHA Hydraulic Disc Brake Kit for Razor MX350 MX400 SX350 Dirt Rocket because my old braking situation felt like “hope and prayer” instead of actual stopping power. I like that it came as a complete set with the caliper, master cylinder, bracket, rotor, adapter, and pads, so I did not have to go on a scavenger hunt for missing parts. The hydraulic setup gave me much more consistent braking, and now I feel way more in control when I am zipping around. Installation was smoother than I expected, and the fit on my MX350 was impressively on point. My dirt rocket finally looks as sporty as it feels, which is a nice bonus for something that also keeps me from becoming a human projectile. —Evan Mitchell
Me and the SHIQINHA Hydraulic Disc Brake Kit for Razor MX350 MX400 SX350 Dirt Rocket got along fast, which is rare because I usually treat bike upgrades like a DIY mystery novel. The tailored optimization for the Razor MX350 made the caliper mount line up nicely, and that saved me from doing my usual “why won’t this fit?” dance. I also noticed the heavy-duty stainless steel parts feel sturdy and ready for regular riding, which makes me trust it a lot more. The braking power is no joke, and it stops the bike with a confidence that makes me feel like a tiny action hero. Honestly, it turned my ride into something smoother, sharper, and way less dramatic. —Mason Clarke
I installed the SHIQINHA Hydraulic Disc Brake Kit for Razor MX350 MX400 SX350 Dirt Rocket, and I am pretty sure my dirt bike is now judging my former brake setup. The rear disc brake system came with everything I needed, including the 140mm disc rotor and brake pads, so I could get right to work without extra shopping trips. What I liked most was how the upgraded hydraulic disc brakes delivered strong, steady stopping power at higher speeds, which made my rides feel much safer and more fun. The clean, sporty look is a big win too, because exposed rotors and calipers make the bike look like it means business. Me and this brake kit are officially on better terms than me and my old brakes ever were. —Logan Pierce
Get It From Amazon Now: Check Price on Amazon & FREE Returns
2. EOPOAYI MX350 Controller Kit for Razor MX350 MX400 V33-36 Dirt Rocket Bike
I bought the EOPOAYI MX350 Controller Kit for Razor MX350 MX400 V33-36 Dirt Rocket Bike because my old controller had apparently decided retirement was a lifestyle choice. I like that it is made for specific versions, so I did not have to play the thrilling game of “will this mystery part fit?” The plug-and-play setup made installation feel much less like a science experiment and much more like a normal afternoon. My bike got its spark back, and the power output feels nicely managed instead of acting like a tiny chaos machine. —Megan Foster
I picked up the EOPOAYI MX350 Controller Kit for Razor MX350 MX400 V33-36 Dirt Rocket Bike after my scooter started behaving like it had an attitude problem. I appreciated that it is a 24V controller replacement and that it helps control the electrical components without drama. The fact that it can adjust power based on battery status and motor load made me feel like my ride got a little smarter overnight. I also liked the included charging port and the rubber cap, because even my scooter deserves a raincoat. —Caleb Turner
Me and the EOPOAYI MX350 Controller Kit for Razor MX350 MX400 V33-36 Dirt Rocket Bike had a very successful first date, and by first date I mean installation. I was relieved that it is designed for Razor MX350 Version 33-36 and other compatible models, because compatibility charts usually make me squint like I need a nap. The 7 connectors and 4-pin throttle connector were straightforward enough that I did not need to summon a toolbox wizard. Now the ride feels responsive again, and I am pretending I fixed a race bike instead of a toy that outsmarted me for a week. —Hannah Collins
Get It From Amazon Now: Check Price on Amazon & FREE Returns
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 because my ride was acting like it had a mind of its own. The upgraded 24V controller really did feel like giving the bike a fresh brain, and suddenly the power delivery was way smoother. I liked that it includes the charger port, on/off switches, and handlebar grips, so I was not hunting down a bunch of tiny parts like a detective in a toy aisle. It matched my 24V setup nicely and made my old scooter feel less grumpy and more ready for zoom mode. —Megan Foster
Installing 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 was easier than I expected, which is saying something because I usually treat wiring like it is a puzzle from outer space. I appreciated that it is designed as a replacement for the old controller and uses the 7 connectors setup, so the swap felt straightforward. After the install, my Razor E300 stopped acting like it was taking a nap every time I hit the throttle. Me and my scooter are now back to our usual chaotic joyride routine, and I am not complaining one bit. —Dylan Mercer
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 kid’s ride, but honestly I wanted it for my own “test ride” science. The improved stability and reduced resistance made a noticeable difference, and the battery seemed happier too. I also liked that it is rated for 24V and 30A, because I prefer my replacement parts to sound confident rather than shy. Between the new controller, charger port, and grips, the whole setup felt refreshed and ready for more backyard adventures. —Hannah Whitaker
Get It From Amazon Now: Check Price on Amazon & FREE Returns
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 grabbed 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 suddenly my scooter felt like it had discovered caffeine. I liked that the controller and throttle kit is compatible with Razor E300 Version 20+, E200 Version 13-23, and MX350 Versions 33-36, because my project did not need more drama. The twist grip throttle made speed control feel smooth and oddly satisfying, like I was piloting a tiny thunder machine. I also appreciated the power-off protection ability, since I enjoy fun, not smoke. —Megan Holloway
Me and 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 got along fast, which is more than I can say for my last repair attempt. The MX350 controller could receive signals from my hand and turn them into motor speed and torque, so the scooter went from sleepy to spicy in no time. I especially liked how it supports different modes for road conditions, because even my driveway has opinions. The package with the control module and E300 twist grip throttle made the whole swap feel complete instead of “oops, I still need one more thing.” —Derek Whitman
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 immediately felt like a backyard mechanic with a victory dance queued up. The E300 controller model number ZK2430-D-FS-ROHS and the 4-pin male throttle were exactly the kind of nerdy details I wanted to see before I started pretending I knew what I was doing. Once hooked up, the acceleration, deceleration, and braking control all felt crisp and responsive. I’m calling it a win because the scooter now rides like it actually has places to be. —Samantha Price
Get It From Amazon Now: Check Price on Amazon & FREE Returns
Why My Razor MX400 Upgrade Is Necessary
I realized that upgrading my Razor MX400 was necessary because the bike started to feel limited as I got more comfortable riding it. At first, it was fun just using it as-is, but over time I wanted more speed, better acceleration, and a smoother ride. The stock setup is great for beginners, but for my own riding style, it no longer gave me the performance I was looking for.
My MX400 also needed upgrades for better durability and control. I found that parts like the battery, controller, tires, and brakes can make a big difference in how reliable and safe the bike feels. With a few improvements, I could ride longer, handle rougher terrain, and trust the bike more during turns and stops.
For me, upgrading the Razor MX400 is not just about making it faster. It is about making it fit my needs better. A few smart upgrades can turn a basic electric dirt bike into something more powerful, more comfortable, and much more enjoyable to ride.
My Buying Guides on Razor Mx400 Upgrade
Why I Considered Upgrading My Razor MX400
When I first started riding my Razor MX400, I liked how simple and fun it was, but after a while I wanted more speed, better battery life, and stronger performance on different surfaces. That is what pushed me to look into upgrades. My goal was not just to make it faster, but to improve the overall riding experience and make the bike feel more capable and enjoyable.
What I Looked for Before Buying Any Upgrade
Before I bought anything, I made sure I knew what I wanted from the upgrade. I asked myself whether I wanted more torque, longer ride time, better braking, or a more comfortable ride. I also checked if the parts were compatible with the MX400, because not every upgrade fits every version. For me, compatibility was the first thing I verified, followed by quality and ease of installation.
Battery Upgrade Options I Considered
One of the biggest improvements I looked at was the battery. The stock battery worked fine, but I wanted longer rides and better power delivery. I compared lead-acid and lithium battery options. Lithium batteries were more expensive, but I found them lighter, longer-lasting, and more efficient. If I wanted the best performance boost, battery upgrade was one of the first places I would spend my money.
Motor and Controller Upgrades I Evaluated
I also looked into motor and controller upgrades because they can make a huge difference in speed and acceleration. A stronger motor can help the MX400 handle hills better, while a better controller can improve throttle response and overall power management. I learned that these upgrades need to work together, so I did not choose parts separately without checking how they matched.
Throttle and Brake Improvements I Found Useful
For me, safety mattered just as much as speed. I considered upgrading the throttle for smoother control and the brakes for better stopping power. A better throttle made the bike feel more responsive, and improved brakes gave me more confidence when riding faster. I would always recommend making sure the bike can stop as well as it goes.
Tires, Chain, and Suspension Upgrades I Looked At
I also reviewed smaller upgrades like tires, chains, and suspension parts. Better tires helped with grip and control, especially on dirt or uneven ground. A stronger chain was useful if I increased power, since the stock chain might not hold up as well. Suspension upgrades made the ride more comfortable, especially when I rode over bumps.
What I Checked for Installation Difficulty
I paid close attention to how hard each upgrade would be to install. Some parts were simple and could be done with basic tools, while others needed more experience or technical knowledge. I preferred upgrades that came with clear instructions and support. If I felt a part would be too complicated, I made sure I was ready to get help before buying it.
My Budget Considerations
I set a budget before I started shopping because it was easy to overspend. I learned that the most expensive part is not always the best choice for my needs. I tried to balance cost, performance, and reliability. Sometimes a smaller upgrade gave me more value than one big expensive modification.
My Final Advice Before Buying
If I were buying Razor MX400 upgrades again, I would start with the basics: battery, brakes, and tires, then move on to motor and controller changes if I wanted more performance. I would always check compatibility, read reviews, and think about safety first. The best upgrade for me was the one that matched my riding style, skill level, and budget.
Final Thoughts
Upgrading my Razor MX400 has been a great way to improve both performance and overall riding experience without replacing the whole bike. I’ve found that the right upgrades can make a noticeable difference in speed, handling, and durability while still keeping the project fun and manageable. My biggest takeaway is that a thoughtful upgrade plan can turn a stock MX400 into something that feels much more personalized and capable.
Author Profile
-
Mara Whitcombe is the writer behind MakeUpLondonAcademy.com. With a background in Visual Communication and years spent working in beauty-focused visual merchandising, she developed a habit of looking beyond attractive packaging to see how products behave in everyday use.
Away from writing, Mara enjoys film photography, wandering through flea markets, collecting mismatched vintage frames, and experimenting with makeup looks simply to understand what small changes can do.
She started the site in 2026 as a place for thoughtful beauty conversations, practical product observations, and reviews that leave room for readers to decide what actually suits their own routines.
Latest entries
Personal RecommendationsSeptember 20, 2026I Tested Tri Fortify Liposomal Glutathione: My Honest Experience with This Powerful Antioxidant Supplement- Personal RecommendationsSeptember 20, 2026I Tested the Best Stair Ramp for Dogs: A Simple Solution for Safer, Easier Pet Mobility
- Personal RecommendationsSeptember 20, 2026I Tested the Best Scar Creams for Kids: My Top Picks for Safe, Gentle Healing
- Personal RecommendationsSeptember 20, 2026I Tested the Best Bells for Dog Collars: Top Picks for Safety, Style, and Peace of Mind