When you push the pedals hardly, you will notice the hub starts slipping and jumping from one engagement point to the other, it is a sign the hub is skipping the engagement points which do not perform rotating torque with the pawls, it happens because of the old hub bike or the hub contains a large amount of grease and also if you have never washed the hub for a long time after rides. the wheel spins freely which is the sign the hub is slipping, the mount of spinning can be judged by pedaling and noticing the angle of the skipping of the freewheel, where the crankset would stop after hitting forceful pull on both pedals.
Judging Angle of Hub Skipping & Slipping:
The angle of the crankset is directly proportional to the hub slipping problem, it can be easily judged when you sit on the saddle on that trail you would start pushing the pedals and the crank legs start rotating if there is a faulty hub with skipping and slipping problem, the crank legs become free at a moment and again starts rotating the wheel, the space of the crank leg when it is free is the angle with the crankset.
If the crank legs started rotating from the top position and till the half of the crankset then it is making an angle of 45 degrees and if the hub is useless then it will allow the crank legs to rotate freely from the top position to downward lower position of the pedal, the crank leg is making an angle of 90 degrees.
If freewheel hubs are slipping and making an angle less than 45 degrees then these can be used for further rides but if it is making more than a 45-degree angle, then you have to replace that skipping and slipping hub with a new one.
Now Lower angle of slipping of freewheel means less number of engagement points are free and are not reaching the pawls due to which the springs are not working and a higher angle of hub freewheel slipping means there are more engagement points which not performing and not responding on the torque force of the wheel.
When you are riding and pedaling regularly without a rhythm then you would feel the space and closed engagement hubs, but when you start to pedal for a ride when the bike is in a resting state you will directly will the difference in hubs.
Engagement points of rear Hub:
Rear hubs are not the same in their manufacturing, there are many brands that have greater space in their engagement points which can be directly felt, when you apply torque force on the pedals, the crankset and legs will free move a bit, it is not a sign of any issue, it is normal. Some brands have too close engagement hubs which do not allow the crankset to move freely.
Torque force of wheel starts rotating the hub, Wheel rotation of large space engagement points completes is slightly greater than the close engagement point hubs and also large space engagement point hubs do not boost the speed of the wheel in the beginning as compared to the narrowly spaced hubs.
Sometimes the engagement points would not perform better and when the hub rotates few points would not get attached with the pawls, and ski[pping occurs, this is reversible and it can easily be fixed in the maintenance of the hub from the mechanic or by the DIY method.
In this case, you have to replace the hub of the same size and the number of pawls and engagement point would also be the same, hubs are of different sizes, while changing the hub you have to change and re-dish the whole wheel(spokes and spoke nipples of the same size), but the wheel remains same.
Sometimes the teeth of the hub have rubbed so much that their edges become short and thin and lose their grip, in such cases the rear hub slips and jumps from one pawl to 3rd or 4rth pawl of the hub, in this, you can replace the pawl with a new one.
Pawls or teeth of the hub work differently for different wheels, these pawls are not universal for every bike wheel and their performance is different, there are some wheels where the hub pawls work from a single pawl to the next pawl when the wheel rotates and the single pawl hubs are usually for road bikes but for mountain bike, there are specialized hub pawls on which the two pawls jump when the wheel moves, on every movement of the wheel, a couple of pawls slide on the next couple but there are also hub types where three pawls slide on the next three pawls on rotating the wheel, it shows that hubs are also differently installed on every bike wheel with different performance.
There are no rear hubs on which more than three pawls would jump at the same time, if you note that it is happening then the hub is skipping and sliding, the wheel needs hub replacement.
Avoiding Rear Hub Skipping And Slipping And Servicing Of Rear Hub:
Hubs need proper maintenance, it can be done by a wheel builder or a mechanic in a proper way, and if you want to do it yourself to avoid spending bucks then here is the method.
Uninstall the wheel from the frame, and remove the drivetrain, derailer hanger, derailer, cassette, and axle. finally, remove the hub, you will notice the hub contains plastic-type seals which are attached to its surface, remove these seals.
Now dip the hub in soapy water and with the help of a toothbrush wash thoroughly the hub and the inner wall of the hub to remove all the dust, dirt, and other residue particles of the trails.
Dry it with a rag or cloth and after 5 to 10 minutes, find some steel tray or mug, fill it with citrus degreaser and leave the hub within the hub for about 4 to 5 hours to remove and avoid the rust in wet trails or when servicing your bike.
After that again dry it with a rag cloth and remove the inner ball or cone bearings including the cup, and order new bearings for the hub, when you received new bearings, build the hub by adding bearings in a proper round shape as the previous old hub, now the new hub is ready to install within the wheel, but before installing, use a recommended hub lube for bleeding.
If you do all this method by yourself, you will save your money and you have to just buy bearings for the hub.
When you are assembling the inner bearings then do it in the right way, if a single bearing moved here and there within the hub, it will affect the freewheel hub, all the inner bearings should be tight and unmovable.
How To Check Hub Skipping And Slipping?
Sometimes it confuses to check the hub whether needs maintenance or it needs replacement, you can use very thin lube or oil to bleed the internals of the hub and use the oil in a large amount, after that pull hard the pedals of your bike and check the hub rotation, if its slipping and skipping more from the previous dry state then it needs replacement, but if it is not slipping then, it is the small issue of pawls, springs or engagement points which needs maintenance then follow the above-given method for hub maintenance.
Grease And Weather Condition Are Also Responsible For Rear Hub Skipping And Slipping:
Some people use grease for the hubs which sometimes gives the opposite effect, the reason is that grease is too thick and especially in summers it starts sweeping and becomes more sticky, due to which the internal bearings of the hub lose their position and these would not participate with the pawls and springs to perform better with the engagement points, as a result, hubs starts slipping and skipping.
Winter seasons also affect badly when the thick greases start freezing on the internal bearings and also on the front and back surfaces of the hub, especially within the pawls, springs and all the number of engagement points which restricts the movement of the hubs and the hub starts taking force and tension.
The thin oils and lubes are the best-recommended fluids used for bleeding purposes, avoid grease for the hubs in harsh weather conditions but if the weather is clear without any dirt and dust on the trails, you can also use grease but in a limited and recommended amount.
Sometimes hub issue is caused by bike storing places, especially in the winter season when it is too cold outside. the bearings would stop working become of too cold, but these are the few days when it’s too cold outside, in these days you store your bike in your warm room and never leave your bike outside on the floor surface which is open to the cold atmosphere or in the garage.