Coleman CT200U-EX Hydraulic Disc Brake Install Guide
If you have pushed your Coleman CT200U-EX into the 50 to 60 mph range with a straight chain and a few engine tweaks, you already know the stock drum brake was never meant for that kind of speed. The drum brake works fine at 20 or 30 mph, but when you add a heavier rider and real velocity, stopping power falls off hard. This guide walks through swapping in an MB200 hydraulic disc brake setup—rotor, caliper, hose, lever, and a new wheel with disc flanges—so you can actually scrub speed when you need to.
Why Swap to a Hydraulic Disc Brake?
The Coleman CT200U-EX comes from the factory with a mechanical drum brake on the rear wheel. Drum brakes are simple and cheap, but they have real limits. They fade when they get hot, they need regular adjustment, and they do not shed water or mud well. A hydraulic disc brake uses fluid pressure to squeeze pads against a rotor, which gives more consistent stopping power, better modulation, and far less fade under repeated hard stops. For anyone running a modified engine or riding on hilly terrain, this swap is one of the most meaningful safety upgrades you can make.
How the Hydraulic System Works
A hydraulic brake system uses a master cylinder at the lever to push brake fluid through a hose to a caliper. The caliper pistons press brake pads against a steel rotor bolted to the wheel hub. Because fluid does not compress, the force at the lever is transmitted almost instantly to the pads. That gives you a firmer lever feel and more precise control than a cable-actuated drum brake. The MB200 setup is designed for a similar wheel size, which makes it a practical donor for the Coleman.
What You Need Before You Start
This is not a bolt-on job. You will need the MB200 brake kit (rotor, caliper, hose, lever, and caliper bracket), an MB200 wheel with disc flanges on both sides, and a handful of common hand tools. You will also need to modify the frame slightly. Here is the full list:
- MB200 hydraulic disc brake kit (rotor, caliper, hose, lever, bracket)
- MB200 rear wheel with disc flanges on both sides
- Button head bolts for the rotor (lower profile than standard hex bolts)
- Socket set and wrenches (metric)
- Angle grinder with a cutting or grinding disc
- Torque wrench (optional but recommended)
- Brake fluid (DOT 3 or 4, as specified by the kit)
- Safety glasses and gloves
Step-by-Step Installation
The process takes about three to four hours for a first-timer, including tire swap and frame grinding. Work on a clean, level surface and have a drain pan handy if you need to bleed the brake. Follow the steps in order to avoid clearance issues later.
- Remove the stock rear wheel, brake drum, brake cable, and brake lever from the Coleman.
- Remove the tire from the stock wheel and mount it on the MB200 wheel. Note the directional arrow on the tire; make sure the valve stem ends up on the brake side and the rotation direction is correct.
- Bolt the brake rotor to the MB200 wheel using button head bolts. Standard hex bolts will stick out too far and hit the frame.
- Test fit the wheel in the frame. You will likely find that the rotor bolts are extremely close to the frame, and the caliper mount tab on the frame interferes with the rotor.
- Grind off the caliper mount tab on the frame that sits near the rotor. This gives the rotor and sprocket the clearance they need. Take your time and remove only what is necessary.
- Install the caliper bracket onto the frame using the provided hardware. Mount the caliper to the bracket but leave the bolts slightly loose for alignment.
- Install the wheel with the rotor and sprocket. Check clearance on both sides. The sprocket side may be tight; you may need to space the wheel or use a thinner sprocket.
- Route the brake hose from the caliper to the handlebar lever. Secure it with zip ties or clamps, avoiding sharp edges and moving parts.
- Bleed the brake system according to the kit instructions. Pump the lever until firm, then top off the fluid.
- Align the caliper so the pads sit evenly over the rotor. Tighten the caliper bolts and spin the wheel to check for rubbing.
- Test the brake at low speed in a safe area before riding normally.
Grinding the frame is irreversible. Before you cut, double-check that you are removing the correct tab and that you have enough clearance for the rotor and sprocket. A mistake here can ruin the frame.
Realistic Time, Cost, and Trade-offs
Expect to spend between three and four hours on this swap if you have never done it before. The MB200 brake kit and wheel are not cheap—budget $150 to $250 depending on where you source them. You will also need button head bolts, possibly a new inner tube if you damage the old one, and brake fluid. The biggest trade-off is the frame modification: once you grind off that caliper mount tab, you cannot easily go back to the stock drum brake. You also add a little unsprung weight to the rear wheel, which can affect suspension feel on rough trails.
Common Mistakes DIY Riders Make
The most common mistake is using the stock hex bolts for the rotor. They stick out too far and will hit the frame, chewing up the rotor or locking the wheel. Another mistake is ignoring the tire direction. The MB200 wheel puts the valve stem on the brake side, and if you mount the tire backward, the tread will not shed water properly. Finally, many riders forget to bleed the brake fully, leaving a spongy lever that feels worse than the old drum brake. Take your time bleeding and use fresh fluid.
Historical Context: Why Disc Brakes Took Over
Disc brakes have been used on motorcycles since the 1960s, but mini bikes stuck with drums for decades because they were cheap and adequate for low speeds. As riders began modifying engines and pushing mini bikes past 40 mph, the aftermarket responded with hydraulic disc kits. The MB200 setup is a popular donor because its wheel dimensions are close to the Coleman CT200U-EX, and the caliper bracket can be adapted with minor frame work. This swap is part of a broader trend of bringing modern braking technology to vintage-style mini bikes.
Street Legality and Safety Considerations
Whether this mod is street legal depends on where you live. In most US states, mini bikes are not legal for public roads at all, regardless of brake type. Some states allow them as off-road vehicles only, and a few have specific equipment requirements for modified bikes. Canadian provinces and other countries have their own rules. Before you ride on any public road, check your local regulations. Even off-road, a hydraulic disc brake is a safety improvement, but it does not make an overpowered mini bike safe for inexperienced riders.
Experienced riders often note that a disc brake gives you more confidence on steep descents and in traffic, but it also encourages harder riding. Many builders report that the stock frame and suspension were never designed for the speeds a modified engine can reach. Research suggests that adding a disc brake is one of the most effective ways to reduce stopping distance, but it is not a substitute for good judgment.
Closing Summary
Swapping a hydraulic disc brake onto a Coleman CT200U-EX is a worthwhile upgrade for anyone who has outgrown the stock drum brake. It takes an afternoon, a few specialized parts, and a willingness to grind a small tab off the frame. The result is a brake that feels modern and stops the bike with authority. Just remember that this mod is for off-road use in most places, and it does not make a heavily modified mini bike safe for public streets. Modifying your mini bike may void the manufacturer warranty and may not be street-legal in your state. Always wear a helmet and ride within your limits.
Video walkthrough: installing the MB200 disc brake on a Coleman CT200U-EX
In this on-camera demonstration, the presenter walks through the full swap on a Coleman CT200U-EX that has been pushed to 50–60 mph with a straight chain. He starts by removing the stock drum brake and wheel, then swaps the tire onto an MB200 wheel with disc flanges on both sides. He points out that the tire is directional and must be mounted with the valve stem on the brake side. After bolting on the rotor, he discovers the stock hex bolts are too close to the frame, so he switches to button head bolts for clearance. He also grinds off a caliper mount tab on the frame to make room for the rotor and sprocket. The video shows the final assembly with the 60-tooth sprocket and emphasizes checking clearance on both sides before tightening everything down. The key takeaway is that this is not a direct bolt-on—expect to modify the frame and use low-profile hardware.
Frequently Asked Questions
1. How much does this hydraulic disc brake swap cost?
You should budget between $150 and $250 for the MB200 brake kit and wheel, plus another $20 to $50 for button head bolts, brake fluid, and any small hardware. If you need to buy an angle grinder or other tools, add that to the total. Used parts can lower the cost, but inspect them carefully for wear.
2. Is this modification street legal in my state?
In most US states, mini bikes are not legal for public roads regardless of brake type. Some states allow them as off-road vehicles only, and a few have equipment requirements for modified bikes. Check your local DMV or highway patrol website before riding on any public road.
3. How long does the installation take for a beginner?
Plan on three to four hours if you have never done this swap. The tire swap and frame grinding take the most time. If you are experienced with mini bike maintenance, you might finish in two hours.
4. Do I need to modify the frame?
Yes. The caliper mount tab on the frame sits too close to the rotor and must be ground off for clearance. This is a permanent modification, so be sure you are committed to the disc brake setup before cutting.
5. Can I use the stock Coleman wheel with the disc brake?
No. The stock wheel does not have the disc flange needed to mount the rotor. You must use an MB200 wheel or another wheel with a disc flange on the brake side.
6. What tools do I need for this swap?
You need a socket set, wrenches, an angle grinder with a grinding disc, a tire iron or bead breaker, and safety glasses. A torque wrench is helpful but not required. You may also need a brake bleeding kit.
7. Will the stock sprocket work with the MB200 wheel?
The stock sprocket may fit, but clearance is tight. The presenter in the video uses a 60-tooth sprocket and notes that everything is very close. You may need to space the wheel or use a thinner sprocket.
8. What brake fluid should I use?
Use the fluid specified by the MB200 brake kit, usually DOT 3 or DOT 4. Do not mix fluid types, and always use fresh fluid from a sealed container.
9. Is this mod worth it for a stock Coleman CT200U-EX?
If your bike is stock and you ride under 30 mph, the drum brake is adequate. The disc brake upgrade is most valuable for modified bikes that reach higher speeds or for heavier riders who need more stopping power.
10. What are the biggest risks of doing this swap?
The biggest risk is grinding the frame incorrectly and ruining the frame. Another risk is improper brake bleeding, which can leave you with a spongy lever and poor stopping power. Take your time and double-check clearances before riding.
RiderMini designs and sells mini bikes and replacement parts. For the parts, tools and accessories mentioned in this article, visit RiderMini.com.
This article is for educational purposes only. Modifying your mini bike may void the manufacturer warranty and may not be street-legal in your state, province, or country. Always consult local regulations and a qualified mechanic before attempting any modifications described here.