Do your uni bearings wear out yearly or more? Mine seem to. What is normal?
I mostly ride street distance on my 36" wheel . On the 24" muni , I ride smalls hills and mounds, and practiced hopping around. I do pretty light weight riding compared to what I see around the forum.
But I’ve found problems with my bearings on both unis having replaced each of their bearings now twice. I replace them when they become the least bit noisey or like today I feel a vibration.
When I replace a them, I replace the both. Often when I open them, the bad one has very little grease, much less than the other. So tonight I opened up the new replacement bearings before installation.
I hate to open the seal of new bearings, I worry about damaging the seal, but I’m glad I did open them. I found one of the new bearings had very little grease. I then stuffed them both with grease. It will be interesting to see how long these bearings last.
BTW, I don’t over tighten the bearings. My new bearings came from ebay and appear to be the same quality as originals.
At least I’m getting good at changing the bearings.
mine were starting to go retarded on my Torker DX, but when I sent it in they gave me new ones and apparenly they greased them well because there is grease that is oozed out and there wasn’t on the first set… is that normal… I have never seen bearings do that before.
There are lots of variables involved. It is difficult to give a general answer about how long the bearings should last because there are many factors involved.
My muni bearings generally need to be replaced about every 9 months or so. Depends on how much winter riding I do in the rain and mud.
My Coker can go longer between bearing replacement. I’m not sure how long. 2 years? 3 years? More? Last time I replaced my Coker bearings was because I replaced the hub, not because the bearings were worn.
I think the biggest factor affecting bearing life is how much care that was taken when pressing the bearings on the hub. If you aren’t careful you can damage the bearing while pressing it on. It’s easy to damage the bearing like that. I’ve done it myself. The bearing will still work well, but its life will be reduced.
Rubber (or plastic) shield sealed bearings seem to do better for outdoor use than metal shield sealed bearings. The metal shield bearings have less rolling resistance and smoother operation, but they let more water and contaminants in.
In the Winter I rub grease around the outside of the seal on my muni bearings or Coker bearings. That’s to help keep water from getting in around the edges of the seal.
If you wash your unicycles be careful not to spray water on the bearings, especially a powerful stream of water.
When installing the bearings you need to be careful that they get pressed on straight. You must only apply pressure on the inside race of the bearing (the small ring). Don’t apply any pressure at all to the seal shield. Don’t apply pressure on the outside bearing race. I use a cut section of an old seatpost tube that happens to be the right size to just fit over the hub axle and press on the inside race of the bearing. Then press the bearing on carefully.
Thank you for the information skrobo and John, It has sorta frustrated me that the bearings wear so quickly. Especially when I relate it to my car where the bearings last for many thousands of miles. But now I’m reminded that these unicycle bearings are fan motor quality bearings, so I imagine unicycling with them can be pretty abusive. It sounds like the wear I’m seeing is close to normal.
One thing I’m guilty of is pounding new ones straight on with a steel hammer using a spacer as John described, not pressing them on. Maybe this shock is further limiting their life of operation.
To get grease deep in to new bearings put some grease in a pan and heat it until liquid, then drop the bearings in, stir around and allow to cool, then dig the bearings out. The liquid grease will have penetrated thebearing sentirely and resolidified. Just be really careful, liquid grease can catch fire and has high specific heat capacity so burns very badly if you get it on your skin.
Eek - sounds a bit dodgy Dave…
I occasionally pop off the outside seal on my muni bearings and poke a bit of grease in, but most of the time they just get ignored. Even with virtually no maintenance they lasted me two years of Dartmoor gritty water before going rough.
My first bearings lasted 1929,70km on my Coker. NBK bearings are standard on the Coker. I switched to SKF bearings after that. No I switch bearings every 1000km. I will now try how long I can cyckle on my SKF bearings.
I doubt it. The axles are hard enough that I can’t see doing damage to them by pressing a bearing on.
Some axles do have problems though in not having a tight enough press fit with the bearing. That makes it possible for the bearing to slide or move on the axle during use. That can be fixed by using Loctite Sleeve Retainer on the axle when pressing the bearing on. I do that for all my press on bearings now just in case.