You’ve finally narrowed your search down and your next 50cc dirt bike will be a KTM. Now, how do you decide between the 50SX and the 50 Mini? Don’t worry, we’re here to help. Today will be taking a quick look at the differences between the two bikes as well as some reasons you may want to choose one over the other.
The biggest differences between the KTM 50sx and the KTM 50 Mini are the seat height and power delivery. The seat on the Mini is significantly lower and the Mini has a much friendlier power delivery when compared to the 50sx due to its smaller carburetor.
The 50 SX seat height comes in at 684 mm. This is substantially taller than the 558 mm seat height on the 50 Mini. With that said, there are ways to lower the seat height of the 50 SX. You may want to start by relocating the shock mount. The 50 SX comes from the factory with the shock mounted on the lower hole. This makes the bike sit a little bit higher. By moving the shock to the upper mount, you can reduce a little bit of height. The other option is to shave the seat. There are pre-shaved seats you can buy or if you feel like it’s something you can handle you can always do it yourself.
The two KTM 50s have the same engine but differ in how that power is delivered to the rear wheels. The 50 SX has a much more aggressive method of power delivery while the Mini delivers power in a much smoother fashion more suitable for a beginner. Both bikes allow for the snappiness to be reduced by offering adjustable clutches. If that isn’t enough, both bikes have a power reduction kit capable of reducing power by 70%.
If you are planning to race this bike there are some important things to consider. The 50 SX will not be allowed to race in the 4-6 class at most tracks. This means you may want to think twice about the SX if it means you will be missing a whole season of racing. If your rider is on the younger end of 4-6 years and looking to get serious about racing, you may not have a choice as only the 50 Mini is legal for this class.
Suspension & Brakes
Both bikes come with both front and rear hydraulic brakes by FORMULA. Using lightweight wave discs, even the youngest riders will find them easy to control with incredible stopping power. The front suspension of both the 50 SX and the 50 Mini is a 35 mm diameter tube with 205 mm of travel. The left fork leg can be adjusted using a simple air pump to better suit the rider’s weight. The rear suspension is where things start to differ. The larger 50 SX allows for 185 mm of rear-wheel travel while the Mini only provides 147 mm of travel. Both suspensions are fully adjustable to perfectly suit the rider’s preference as well as track conditions.
The KTM Mini is a fuel-injected bike whereas the KTM 50 SX will require premix. In both cases, you will want to carry extra oil with you to the track. Nothing is worse than getting to the track, running out of fuel, and realizing you forgot your oil to mix it with. The additional oil pump on the Mini can make some aspects of servicing a little more difficult and lead to another possible point of failure. This minor inconvenience is offset by the need to premix the oil/fuel for the 50 SX.
If we had to choose a bike it would be the 50 SX. Young kids move up in bike sizes so fast it’s hard to justify spending the extra money for Mini. The power on this bike can be reduced and the clutch can be tuned to mellow out the takeoffs. The height of the SX is still bit of a problem but by shaving the seat and moving the shock mount this can be mitigated. Unless your child is absolutely too small to ride the SX, we feel it is a better choice. Unfortunately, this means you won’t be racing in the 4-6 50 Jr. class. We feel that unless your child is competing at Loretta level, we feel the money saved from skipping the Mini and moving straight to the 50sx is worth it. If you are planning to race competitively, have a younger rider, and are willing to spend the cash, your best bet is to run the KTM 50 Mini. It hands down dominates the smaller class and your young rider will be able to maximize the time riding it until they need to trade it in for a bigger bike.