Scooter bearings: how to choose and replace?

Sooner or later a moment comes when the scooter rolls with difficulty or does not move at all. In addition to the breakage of the wheel itself (rim, cast or inflatable tire), as well as damage to the axles and rudder bushings, movable elements may fail, without which the bushings and axles would quickly wear off - bearings.

Before removing a worn bearing, select a new one correctly. The fact is that if the diameter of the balls and cages is incorrectly selected, the wheel will dangle, and after a dozen or a half you will smash the new bearings to smithereens.

Basically, the wheels on children's scooters have a diameter of 98 or 100 mm. There are also models with a wheel diameter of 80, 100, 110, 125, 145, 175, 180 and 200 mm.... The larger the wheel diameter, the better the scooter's cross-country ability on increasingly bad roads with cracks, gravel, broken asphalt and other obstacles. Bearing types are presented brands Flashrider 360, Proto Gripper, Slamm, BlackVoice V2 and several others.

In addition to this, there is another classification by type, which is important in this matter: sealed and shielded bearings. Shielded bearing rollers prevent dust and sand from entering the ball mechanism. The sealed ones give the rider a precise handling when cornering and are more resistant to vibration and shock. They are also equipped with a rubberized or Teflon layer that retains foreign particles, and they last long enough without the need for more frequent introduction of oil or grease into the mechanism.However, changing the balls in them is not easy.

The ball bearings for scooters are no different from those used in skateboards and inline skates. Basically this is the 608th model. Each of the wheels has 2 such bearings. Marking - abbreviation ABEC (special group of developers of industrial bearings), accuracy class - from 1 to 11. The higher the accuracy class, the longer the bearing will work, but the steel grade is also important.

A high-precision bearing is more wear-resistant - nothing dangles in it, it can be subjected to significantly higher loads. It should be as wear-resistant as possible, but not so much that it is not the bearing itself that is worn out, but the bushing. High quality bearing steel is found in well-known manufacturers such as KMC.

Before choosing and replacing a bearing, remember that wheel hubs are available in a diameter of 6 and 8 mm. The diameter of the sleeve determines how this bearing can be pulled out. You can estimate the diameter of the bushing by looking at the axle itself.

The 8mm wheel hub has a "floating" mechanism - it is fixed, and its end moves slightly back and forth between the two ball bearings that clamp it. To remove such a bearing, pry it with a hex wrench and pull it out easily.

Removing the bearing from the 6mm bushing is a little more difficult. He does not poke on, but knocks out. To do this, press on the bushing, and not on the bearing itself, otherwise you will bend its separators - it will squeeze it out of the mount by itself. The sleeve resembles a thin ring in the center of the bearing itself, its thickness around the entire circumference is no more than a millimeter. The pressure can be significant - some manufacturers press the bearing securely into the outside of the hub located in the center of the wheel rim. Any piece of iron or stick that is suitable in diameter will do.

The wheel bearing itself is an inner metal wheel spinning on the outer one. A clear and easy glide is achieved by rolling the balls over these surfaces. The durability of the balls and these rollers is ensured by a careful dimension ratio that excludes their backlash (looseness in the gaps), and thickened machine oil or grease is added to the ball bearing to prevent premature boring.

Removing the thrust bearings pressed into the sleeve is the most difficult task - especially the steel wheel molded into the scooter wheel rim. The latter option may require moderate heating of the bearing and sleeve, which, at the slightest overheating, is fraught with a skew of the rim. But this problem can be solved if you have a regular and wooden hammer, a T-shaped hexagon.

Follow the steps below to remove the wheel bearing safely and quickly.

1. Use a T-wrench to push back the spacers, isolating rollers and balls to prevent foreign particles from entering the mechanism.
2. Place on the opposite side, coinciding with the direction of removal, a spacer or bolt with washers and nuts, and with light blows with a wooden hammer, press out one or more bearings from the bushing.Before that, place the wheel with one edge on some solid object, or position it so that the center of the rim is in the gap of the stand on which you press out the bearings.
3. Place the T-shaped wrench so that its working (impact) end is no larger than the bushing diameter. Insert the end into the bore of the ball bearing to pry off the gasket.
4. Attach the end of the wrench to the retaining piece that acts as a bearing ejector. Place all weight on the wheel to be machined and press out the bearing crown held by the key. The gasket will be removed at the same time.

After removing the old bearing from the wheel, prepare a new one. The ideal solution is to purchase a dozen wheel bearing kits for future use (after purchasing a scooter). It is advisable to purchase them from the same manufacturer - only a set of the same size is suitable for each of the scooter models, no interchangeability is allowed here. To install a new bearing in the scooter wheel, do the following:

• install the bolt on the new bearing;
• apply a little engine oil or lithol (or grease) to the crown with balls;
• install the ball bearing itself in the center of the wheel - where its seat is located;
• Using a wooden mallet, carefully press it into the wheel hub.

Bearings on the steering wheel protect the steering column from wear, just as wheel bearings protect the wheel itself and its axle. The bottom bearing contacts the fork holding the front wheel - just like on a bicycle. Upper - prevents the stem from dangling and also provides easy turns when needed.

To replace the ball bearing kits on the handlebars of the scooter, do the following.

1. Remove the steering wheel itself. To do this, use a hex wrench to lower the clamp. Observe the sequence so as not to lose control of the screws.
2. Unscrew the steering column, which contains the bearings. To do this, completely unscrew the locking and adjusting nut.
3. Pry the ball separator with a screwdriver and remove it, pull out the steering adapter, followed by the lower ball bearing.
4. Clean the axle and head tube from traces of old grease. Insert the new lower ball bearing, slide the adapter onto the axle and install the upper ball bearing. Remember to lubricate the bearings - oil or grease will eliminate the friction of the balls and cages on the axle and adapter.
5. Set the adjustment on the inner nut - the steering wheel should not dangle when cornering. Tighten the lock nut over the previous one.
6. Install the handlebar and tighten the retaining clip.

Substitute a block or brick to prevent the scooter from rolling forward or backward. Raise the front wheel and turn it so the steering wheel turns with it. With an ideal steering wheel setting, the wheel will not wobble. Sometimes the repair is limited only to tightening the entire system to eliminate the play of the ball bearings.

If the steering column is loose, remove the steering wheel itself, loosen the lock nut and tighten the adjusting nut under it. This can be done using a regular open-end wrench to fit. Having achieved the absence of play in the steering wheel, tighten the lock nut and return it to its place. If it gets stuck - for example, it turns with a noticeable force, grinding and crackling - replace the worn out set of balls. Steering columns most often use 13-19 ball cages.

If the wheel itself is sticking, it is possible that the ball bearings on it are destroyed. When a breakdown occurs on a wheel that has a brake, you will need to remove the brake pads to pull it out. The shock absorber can also be temporarily removed. Further steps for replacing the wheel bearings remain the same. The number of balls on one wheel cage is most often 7-9, since the wheel axle has a small diameter compared to the steering axle.

For information on how to replace the bearing in a scooter, see the next video.