Wheel Bearings

Discussion in 'Rack Mounted Engines' started by Hive, Jul 14, 2008.

  1. Hive

    Hive Guest

    I was going to enter the below in one of the threads on Split Bolts and Drive Rings under "Snapping on the Drive Ring" or "GEBE Don's ..." threads, but it is new topic, so here we go.

    I was out pedaling and a tech at local garage saw me fiddling with my balking front derailleur and came out and admired the motor (not running or connected to ring) and we had a nice talk.

    He wondered if the wheel bearings would take the stress of higher speeds?

    I had no clue and still do not. Seems they should work as is but I know so little about this stuff.

    Might be worth exploring, particularly for motorized commuters and fast runners.

    Food for thought.
    Last edited by a moderator: Jul 14, 2008

  2. Nuttsy

    Nuttsy Member

    It can depend on the bearings your wheels have and the quality of the hub. Years ago my local bike shop mech. turned me on to removing the caged bearings the cheaper bikes use and just pack free loose bearings in its place. That allows room for one or two more bearings and therefore better support. The quality of the bearings and the hub then becomes the issue. So using quality parts will get you down the road. All that aside, there is much more stress on the spokes than the center of the wheel, but, naturally you're going to want to keep a close eye on both and do regular maintenance. Then you can evaluate the condition of the bearings. Another option would be a different hub that uses sealed bearings.
  3. Here's my take on that. Look at scooters and motorcycles. There's a reason for the heavy duty bearings. I don't know about Whizzers,though. I would assume their bearings should be more heavy duty than a bicycle.
    This is why I keep my speeds down.
    I'm sure a bicycle can handle the speeds,but can it handle PROLONGED speeds?
    I keep my bearings greased monthly and I check for wear. But I KNOW not everybody does this.
    This was partly the reason that I switched my happy time over to another bike. My Diamond back had quick release bearings and the bearings and race were looking worn down when I did my last monthly greasing.
    My rear rim was getting warped pretty bad too.
    My new bike is old but made strong. I'm sure this bike would last a bit longer.
    Last edited by a moderator: Jul 14, 2008
  4. Mountainman

    Mountainman Active Member

    Most bicycles we would think -- are made for at least -- at times -- very fast high speeds -- down large hills -- 40 mph maybe -- BUT -- to run a bicycle MB at those speeds daily requires a good eye mixed with some maintenance -- if wheel bearings while spinning wheel make ANY noise or we feel something rough going on -- time to take it apart and check those bearings and races.. Happy Riding from - Mountainman
  5. My bearings went in less than 100 miles in my rear wheel. I kept them greased, and greased them when I got the bike new. I replaced the bearings in the rear and removed cages, and installed more bearings.
  6. Hive

    Hive Guest

    My O My!

    What a treasure trove of insight.


    Project this winter will be to replace cages with loose bearings and grease, with lithium?

    I think I will let the basic axles go for time.

    I motor about 25% of the time, if that ...

  7. uncle_punk13

    uncle_punk13 Guest

    If I might be so bold as to add- In addition to the above mentioned "Hip tips and tricks", I also use a high quality Automotive type bearing grease, seems to work very well for higher speeds as it doesn't melt down and run out of the wheels nearly as fast or often...
  8. rossfree

    rossfree Member

    My two cents...

    A 26 inch wheel doing 30mph is only turning the blazing speed of 388 RPM. This is not a speed likely to burn up grease or put undo stress on bearings.

    A clean race, descent grease and properly assembled bearings should give you a long life. Overtightening the nuts holding the bearings together could significantly shorten their life, as would dirt or grit finding its way in.

    Poor quality materials in the bearing itself can allow premature failure but if they are properly lubricated... I'd say even they should last a reasonably long time.

    I like the cage removal... adding extra balls... but doubt that all but the heaviest riders really need to do so.

    Trail riders would likely need the best bearings... and I'd really entertain sealed if it were within monetary reach.

    There are a lot of old bikes still tossing around out there with the same bearings that came with them. If you keep them clean, dry and lubed I should think you will get many years out of all but the very cheapest bike bearings.

    That's just my two cents. I don't discourage anyone from improving the bearings on their bikes... or any other components. By all means do so.

    Happy trails,

  9. kerf

    kerf Guest

    I've had no problems with loose bearings but the higher end hubs are going to sealed ball bearings. The Staton rear hub has four sets of sealed ball bearings, maybe overkill but makes me feel good anyway.

  10. I dont know that it is the speed of the wheel, but the stress of the weight of the rider pushing down on the bearings, as well as the motor pulling the drive side of the wheel forward constantly. I replaced my rear bearings within 100 miles and it was only the drive side that was bad....
  11. Pablo

    Pablo Motored Bikes Sponsor

    My DB MB is over 20 years old. I have had a motor on it for the last 6 months.

    I have been riding it very hard, I mean slamming it and then going 40 mph then braking hard then downshifting and hitting the fuel up the drive over 3" ruts....all to stress the jackshaft as much as possible....

    Until this weekend, I had never even seen the bearings.

    I opened the rear up. The grease was a bit aged, but all the balls and races were perfect. I cleaned everything perfectly and buttoned it up with some Amsoil synthetic racing grease.
  12. duivendyk

    duivendyk Guest

    I think total milage and especially contamination with abrasive dirt, more than speed per se (within limits) are the principal factors affecting bearing life.Of course quality of components such as surface hardness and the load factor (load to bearing size) are additional factors affecting bearing life expectancy
  13. augidog

    augidog Banned

    gotta love the steel "105G" shimano-coaster wheel

    i've used the same shimano coaster hub that's currently on "bluto" for over 1500 miles with 3 different styles of drive lashed to it, i tear it down and grease it up once in a while & keep a close eye on the bearing-adjustment...

    tho the spokes aren't happy about some of the things i've put 'em
    thru, i see no signs of this bad baby giving in any time soon :cool:
    Last edited: Jul 14, 2008
  14. rossfree

    rossfree Member

    Hi Misteright,

    I don't question that you had a problem. And I don't want to state that what I said applies in every case. The bearing problem you had is curious. I don't know what caused it other than what I mentioned before.

    But I do not believe that the small engines we have added to our bikes do not add much in additional stresses to the bearings... other than we will likely ride the bike more miles than the normal rider.

    The GEBE kit puts more stress on the spokes than anything else. I've broken three and have new 12 gauge spokes on order. The sprockets being bolted onto the bike hubs could cause bearings problems if the hub was distorted in the process of bolting them on. I have no experience with this method and likely this issue does not come up with any frequency or we'd hear about it here.

    Steel balls will take a LOT of force. The race is likely the weakest link in the bearing hubs. If the race became distorted or the lubricant dirty or gritty you can expect undue wear and tear. Also overtightening the nuts squeezing the bearings to the hubs can put significant loads on the bearing races.

    If you are using a chain to a relatively small sprocket then fairly significant loads are likely being placed on the axil and hub. If they are enough to distort either then you have likely found your problem.

    Then there's the material quality influence.

    My two cents only... I make this stuff up as best I can. :)

  15. uncle_punk13

    uncle_punk13 Guest

    LMAO!!! Great stuff that...