March 25, 2017 at 6:47 pm #815795
If you’re a bike geek like me and reads all the news web sites and such, you’ve no doubt come across a few of these videos showing how well wheels, bottom bracket, derailleur pulley, etc. bearings spin. A couple examples below.
Well I am writing this to tell you that “testing” a bearing like that is completely useless. Find a clapped out old Supercycle from the 70s, put it in the stand, and make sure the front is bone dry and sounds like a rock tumbler. If you get the hub adjustment half decent, you can get that wheel to spin all day. But the bearing is still screwed! It needs to work with a rider on it!
Case and point, the following video examining “frictionless” bearings:
Key quote from the video: You don’t run a bearing if there is zero load! What’s the point of having a bearing if there’s no load?
As a side note, do yourself a favour and subscribe to that AvE Youtube channel. Tons of amazing videos. Very educational, very funny and he puts up a couple new ones a week usually.March 27, 2017 at 11:25 pm #815860
IMO there’s only 2 things that really matter for bearings used in mountain bike parts:
1) Do the seals actually seal out contaminants?
2) Can the bearings handle heavy impact loads?
If the answer to either of the above is no, the bearing’s going to have an unacceptably short life.March 28, 2017 at 8:36 am #815861
The thermo gun had me lol’ing
I would agree a properly sealed, greased, broken-in bearing “feels” faster but would like to see someone test for watts needed to spin a device under load with both regular bearing and low friction.
To me bearings are a service part anyway, meant to wear out and be replaced at interval.
Also think most bike bearings should be angular contact style to take both radial and axial loads due to the many ways bikes put stress on things while wiggly through the trails.March 28, 2017 at 2:30 pm #815863
correct. Ball bearings have no business on pivots on bikes. It’s a cost savings for companies.
Radial loads can be taken up by axial washers or bearings, and a needle bearing on shaft setup similar to what Nicolai does (best I’ve seen yet) which is what motorcycles use.
For bearings that actually rotate, then angular contact would also work, esp for wheel bearings. but again, cost and weight. I think the only angled contact bearings that exist on a bike is the headset, correct?March 28, 2017 at 6:22 pm #815867
For bearings that actually rotate, then angular contact would also work, esp for wheel bearings. but again, cost and weight. I think the only angled contact bearings that exist on a bike is the headset, correct?
There are some bottom brackets that use angular contact bearings and Shimano hubs & pedals use them as well so it is possible to have a bike where it’s all angular contact. But for most bikes, yeah, the headset’s the only one that isn’t a cheap radial bearing.March 28, 2017 at 7:48 pm #815871
I have two bikes, and all the bearings on both are angular contact with the exception of the derailleur pulleys, and 1/2 freehub bearings on one of the hubs (the other of which is a roller bearing assembly).
As far as I know, all bearings Shimano makes for all their components are angular contact, except derailleur pulleys, possibly some freehub body bearings, the roller bearings in Shadow Plus (clutch) derailleurs, and the small cartridge bearings in XTR and Saint shifters. This means all hubs, pedals and bottom brackets. Chris King also uses angular contact bearings almost exclusively.
However, it is true that most standard cartridge bearing hubs use linear bearings, including higher end DTs and Hopes. Angular contact bearings are becoming more common, but it’s still fairly slight.March 29, 2017 at 9:29 am #815902
Ah yea, forgot about how shimano had loose ball bearings against a somewhat angled race, making it effectively a angular contact ball bearing. Not ideal like an angular contact roller bearing, but yea, this is much better for a hub. Didn’t realize they are doing it for their BB’s as well, I remember the older ones were also loose balls against a race. That green grease lasted forever!March 30, 2017 at 10:25 pm #815951
That green grease lasted forever!
Fun fact: That grease (currently named Shimano Premium Grease) is one of the very, very few Shimano products that is not made by Shimano themselves. Reason being is that Shimano couldn’t manage to make a better grease for the job. So that grease is made by a German company called Agip. The factory name for the stuff is “Autol Top 2000 Super Longtime Grease”.
SUPER LONGTIME GREASE! So true.
It’s pretty expensive, but is some pretty amazing stuff, and you can get away with using about half as much as most other greases in most applications. I recommend buying some.
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