It's not an issue when riding leisurely, but when riding down from the mountains with a full load of camping gear, don't you get the impression that the CT125 Hunter Cub is not stopping as it should. In particular, those who own other sport bikes as well, or those who use the Hunter Cub as a second bike for commuting or camping, may have the impression that it does not stop as well as expected even when squeezing the brake.
It's not that you need brakes so powerful that you can jackknife with one finger, but you want them to stop a little more firmly. So you changed the brake pads, calipers and master cylinders, but that didn't seem to make the brakes that much more effective. For those of you who have encountered this situation, we recommend enlarging the diameter of your brake disc (changing to a big rotor)! You might not have thought of this since it's usually something only hard-core enthusiasts would do.
- Situations where the brakes don't stop well
- What is needed for the brakes to work well (to strengthen the brakes)
- Things that are irrelevant to braking effectiveness
- The easiest thing to do is replace the brake pads
- Raise the bar a bit with master cylinder and caliper replacement
- Increase coefficient of friction with difficult disc replacement
- Too good to be true? Large-diameter brake discs (big rotors)
- Normally, increasing the disk diameter is extremely difficult
- Big rotors make the brakes work so much better with almost no disadvantages
- If you don't ride hard on rough forest roads, it's best to replace the entire wheel
Situations where the brakes don't stop well
The Hunter Cub CT125 has been very popular ever since its release. Some reasons being its versatility, its simple coolness, and the fact that it is the perfect partner for camping, which has gotten more popular since the Covid pandemic started. If you had mostly been using it for commuting, many of you may have been surprised to find that the brakes don't work as well as you thought they would when the bike is fully loaded with camping gear. Camping tours often take you on unfamiliar roads, and the roads around campsites deep in the mountains often have a lot of ups and downs, so there are probably many people who have had a chilling experience at the unexpected appearance of a sharp downhill curve.
What is needed for the brakes to work well (to strengthen the brakes)
What is necessary for brakes to work well to begin with? The act of braking is converting kinetic energy into heat through friction. Therefore, if the friction force is increased, the brakes will work better. Changing the materials used for tires, brake pads, and brake discs will change the coefficient of friction, which in turn will make the brakes more effective. It is also effective to increase the force with which the brake pads grip the brake disc. If a tire with infinite gripping capability existed, doubling the strength at which you grip the brake would make the brakes work twice as well. But doubling your grip strength is pretty hard, or rather impossible.
Things that are irrelevant to braking effectiveness
It may come as a surprise, but there are parts that are thought to improve braking performance, but in fact do not. Highly rigid brake calipers, radial pump master cylinders, and stainless steel mesh brake hoses, by brands such as Brembo, may seem to improve braking performance, but in fact, replacing these parts does not make the brakes themselves work better.
However, you may feel like the brakes work better after replacing them. This is because it improves the feeling of the brake, so that you will be able to instinctively know that you can actually grip the brakes a little more than you thought was possible, and you will be able to brake with more confidence. No matter how strong the frictional force of a brake pad is, it is useless if the braking force is 0% or 100%. It is only by being able to control the brake pads to the finest degree that the powerful frictional force can be utilized, so replacing calipers, master cylinders, and mesh hoses is not a waste of time. Please do not misunderstand.
The easiest thing to do is replace the brake pads
The easiest thing to do is to replace the brake pads with ones that work well, because the brakes will work better if the force of friction is increased. Those of you who were not satisfied with the braking performance of your Hunter Cub, probably tried replacing the brake pads with ones that looked like they'd work better than stock. Of course, if you replace the brake pads with high performance pads, they will work better. However, it is a fact that the durability tends to be inferior in exchange for the effectiveness. Also, since only you know which brand of pad is best for you (even if it feels great to others, it may not be right for you), you probably need to try out quite a few in search of the best pad.
Raise the bar a bit with master cylinder and caliper replacement
After pads, the next easiest thing to try is a master cylinder replacement. However, master cylinder replacement is not that common, as it is not an easy customization that anyone can do. For example, if you replace the master cylinder with a radial pump type, that alone will improve the feeling and braking. Furthermore, if it is replaced with a master cylinder of a smaller diameter than the stock one, it is possible to utilize Pascal's law in which greater braking power can be obtained with an increase to the lever stroke, but with less force. However, replacing the master cylinder involves bleeding the air out of the brake fluid, which is a daunting task if you are a novice at maintenance. In addition, you may be wondering what to do about the brake light switch, or whether you need to custom-ordered a new brake-hose because the routing will change. There will be a series of related issues to think about, so it might be quite the challenge.
Increasing the diameter of the brake caliper piston also makes it possible to obtain a large braking force in exchange for the lever stroke, but such convenient calipers do not exist. You'd have to to search for a caliper that can be used and create a custom-made bracket to mount it, which makes this also a less than realistic choice.
Increase coefficient of friction with difficult disc replacement
Another method is to replace the brake disc (instead of the brake pad) with one that has higher friction force. Unlike replacing master cylinders or calipers, there is no need for troublesome work such as bleeding air, so the replacement work is relatively easy. As expected, it is not as easy as replacing brake pads, but if you are able to remove tires, you will have no trouble replacing the disc.
However, although it is easy, this method it actually impossible. This is because there is no aftermarket disc for the Hunter Cub that works better with the same shape as the stock disc. It may be possible if you do a custom one-off modification of a disc that is not for the CT125 Hunter Cub, but then it's no longer easy.
Too good to be true? Large-diameter brake discs (big rotors)
In short, in the case of the CT125 Hunter Cub, normally there is no other way to make the brakes work better than to find brake pads that work well. What we are going to introduce here is a big trick that goes beyond that "normal", which is to increase the diameter of the brake discs. In fact, the various things mentioned above are only the case if the brake size is the same as stock. If you can change the conditions and increase the diameter of the disc, all of these trivial things will blow away. Brake disc enlargement (big rotor) is a dream-like customization that dramatically improves braking efficiency and feeling by moving the braking force generating position closer to the tire circumference without replacing pads, calipers, or master cylinders.
Normally, increasing the disk diameter is extremely difficult
To increase the brake disc diameter, a caliper support is required to move the caliper position slightly to the periphery of the wheel. To begin with, a convenient brake disc that can be mounted on the wheel and whose only difference is the larger outer diameter must also be prepared. We know that the larger diameter will certainly improve the effectiveness and feeling of the brakes, but the hurdles are too high for anyone but the most dedicated customization fanatics to attempt.
Big rotors make the brakes work so much better with almost no disadvantages
Custom brake disc enlargement is a dream, and there is a great kit that makes that dream come true for the CT125 Hunter Cub. EVATEK's 260mm Front Brake Disc Kit (price including tax: 36,080 JPY) and 220mm Rear Brake Disc Kit (price including tax: 45,650 JPY)!
The EVATEK brand name is not yet well-known, but you can rest assured because they are an original product brand by KOKEN, who are famous as a distributor for Brembo and for their anodizing kits. This product is bolt-on for both front and rear! There is no need to give up because of a difficult installation process. You can easily increase the diameter just like changing discs. Since the front and rear discs are not sold as a set, it is possible to use only the front or only the rear depending on your needs. For example, if you are not dissatisfied with the front brake performance but want more braking power when fully loaded with luggage, you can install only the rear. If you are afraid of slipping down from the front when panic braking because of the reinforced brakes, installing only the rear is also recommended. On the other hand, if you don't go camping and aren't concerned about performance when carrying a large load, but want to improve your ability to avoid danger while commuting, you may want to install only the front brakes.
Since front and rear discs are sold separately, you can purchase only the necessary one when replacing worn discs. The disadvantage of installing these discs is that the larger disc diameter increases the gyroscopic effect, which can worsen handling, but this should be negligible in the speed range of the Hunter Cub. The braking performance is improved to an unbelievable level, so Hunter Cub owners should not miss out on this.
Front Brake 260mm Disc Kit Features
First of all, the disc diameter, which is the most important part of this kit, will be increased from 220mm to 260mm. The diameter is increased by approximately 18.2% just by installing the kit. The stock brake calipers and brake hoses can be used as they are, so there is no need for additional expense. This product is all you need to complete the diameter enlargement. Furthermore, while the stock discs are simply rigid discs, EVATEK's discs are semi-floating. Despite the small disc diameter, it is perfectly designed with equally spaced floating pins.
The inner disc is made of lightweight aluminum and you can choose from black, red, and gold anodized colors to suit your preference. If you look closely, you will notice that the holes drilled in the inner disc are large and chamfered to save weight and make it easier to clean, but the holes drilled in the stainless steel disc are not chamfered. This is similar to the Brembo brake disc design and must have been designed with the same concept in mind. The superb fit is impressive as it is done perfectly in the extremely narrow space available for a small-displacement bike, and it has a superb finish that, in addition to the actual performance, gives you satisfaction just by looking at it. Since it is made by a company that specializes in anodizing, the texture of the anodizing is also beautiful!
Rear Brake 220mm Disc Kit Features
With this kit the diameter of the rear disc increases to 220mm, while the stock disc is 190mm. The diameter is increased by approximately 15.8% by simply installing this kit. As with the front, there is no need to replace the calipers or brake hoses and the appearance is also of the highest quality. The reason why the price is higher than that of the front, even though the disc is smaller in diameter, is because the set includes a huge caliper bracket machined from aluminum. While the front bracket was a flat plate, the rear bracket replaces the entire stock caliper bracket, which is integrated with the axle shaft.
Since the main purpose of these kits is to make the brakes more effective, the manufacturer did not want to use parts such as caliper supports to move the caliper position to the rear, because that would reduce brake rigidity. This machined bracket is the reason why the caliper is so stiff and rigid despite its larger diameter. The rear caliper bracket also serves as an axle collar that determines the position of the rear wheel, so even though the caliper bracket is made of aluminum, the precision of the rear axle can be expected to be improved by machining the caliper bracket from cast metal. The texture of the caliper support is unique to machined aluminum parts, and the custom look that can be seen peeking out from behind the rear shock exceeds that of the front.
If you don't ride hard on rough forest roads, it's best to replace the entire wheel
In fact, in addition to the above large-diameter brake discs, EVATEK also offers other parts to enhance riding performance. Namely, their Front and Rear Cast Wheel Set (price including tax: 132,000 JPY).
Even though the CT125 Hunter Cub is suitable for camping, that doesn't mean it's always being used for camping only. As a second bike, it is likely to be used mostly on paved roads for commuting to work or school. Even when camping, most of the trip will be on paved roads, and you will probably only ride on dirt roads just before or inside a campground. If this is the case, there is little need for spoked wheels, and cast wheels are more advantageous in terms of performance. Cast wheels eliminate the need for tubes and can be fitted with tubeless tires for on-road use. In addition, EVATEK's cast wheel kits have a wider rim width of 1.85 inches, so 17-inch high-grip tires can be mounted. In addition to eliminating the worry of loose or broken spokes, this kit also drastically reduces puncture trouble, which greatly reduces anxiety during long tours. Since accessories such as bearings and distance collars are pre-installed, this cast wheel kit can also be installed as a bolt-on.
However, we have some bad news. This cast wheel kit has attracted so much attention from savvy riders that the supply is not keeping up with demand, and orders have been suspended. So, even if you wanted to you cannot purchase it right now, and of course that goes for Webike also (As of July 2023). The timing for resumption of supply has not yet been determined, but it is hard to believe that this product would be discontinued, as it is very popular. We recommend that you press the "Ask Webike for next delivery date" button and wait for them to get back in stock. Especially for those of you who use your Hunter Cub mostly for commuting, we recommend that you get the whole set including the larger diameter brake discs for the front and rear! If you think of it as an insurance policy for increased braking power and safety in emergencies, there is no reason why you should not install them all!
