[mandown]

i've noticed the pimp move on frames is to have the pivots use needle bearnings. word is, they are smoother and bear stress better. are there any companies out there using needle bearings in their hubs or cranks?

seems to me a needle bearings in either application could allow for a larger diameter hollow axle to save some weight.

thoughts?

 

[davep]

They need to be used in conjunction with another type of bearing as they will not support axial load. When they are used in a frame as pivots (turner for example) the pivot has a synthetic (plastic) thrust bearing (washer) between the two frame parts to support loads along the axle.

The SKF ISIS bb uses a roller bearing on the drive side to support the (slow, radial) load on that side. They do have cartrage bearings (two I think) as well in the bb to deal with other loads.

They are used in hubs in the freehub body, where there are very high radial loads. If they were used somewhere else, they would have to be in addition to the existing bearings already in the hub. This would add weight and friction.

Along these same lines..why have more headset mfg not used taper roller bearings..they are made for EXACTLY what a headset does. The best headsets currently use a angular contact bearing. These are designed for higher speeds and lower loads....not what a headset sees.

I dont think hubs fail that much from loads. They get contaminated for sure, but the current bearings used for hubs are pretty appropriate. Things like pivots, headsets, and bbs could definately made more durable by the use of different bearings than the current norm....but that would cost $$.

 

[-dustin]

Kings use needle bearings in their freehubs, as davep alluded to. there used to be an XTR and D/A bottom bracket that used them...XTR was a 950, i believe.

 

[DIRTWRKS]

Suspension pivots should be using " Spherical bearings" which are really like a blend of both radial and needle bearing types , they handle radial loads and a would last much longer etc.
I am suprised that no frame designers have incorporated them into their designs.

 

[jvnixon]

hadley also has a needle bearing in the hub.

It'd be interesting to get some INA double row angular contact bearings in hubs.

 

[jvnixon]

Suspension pivots should be using " Spherical bearings" which are really like a blend of both radial and needle bearing types , they handle radial loads and a would last much longer etc.
I am suprised that no frame designers have incorporated them into their designs.

Knolly does i believe

 

[davep]

Suspension pivots should be using " Spherical bearings" which are really like a blend of both radial and needle bearing types , they handle radial loads and a would last much longer etc.
I am suprised that no frame designers have incorporated them into their designs.

Are you talking about plain bearings or roller element? Plain spherical bearings(rod end bearings) allow angular movement between components, and in my experience would come no where near holding up to pivot loads...roller on the other hand, would hold up for sure, but still allow angular freedom..not sure that is a good thing ...athough it would allow poor frame alignment and tolerate LOTS of flex...maybe S.C bikes should look into this


Knolly uses angular contact bearings for main pivots and regular cartrage (deep groove) bearing elswhere as far as I can find.

 

[dhkid]

the dual row angular contact bearings are a good idea, but for some reason, they come with some play when they are new. maybe its just a bad design for that bearing...

 

[spacemanspiff06]

you don't find needle bearings in hubs because they roll slower then regular balls. xtr and dura-ace stil use the old-school cone and ball design becasue, if adjusted right, thats the smoothest thing out there.

 

[MorewoodKid]

the dual row angular contact bearings are a good idea, but for some reason, they come with some play when they are new. maybe its just a bad design for that bearing...

Its probably because the bearing is designed to work under load...

 

[knollybikes.com]

Knolly uses angular contact bearings for main pivots and regular cartrage (deep groove) bearing elswhere as far as I can find.

Yup, that's exactly correct. I'm not a fan of needle bearings in frames. Theoretically they are a good idea, but the implimetation always never works out that well. Plus they require a LOT of width to made them work properly (as DaveP mentioned) because the needle bearing is wide, then you have the seal width, then the axial thrust bearing. They end up being side loaded, contaminated and eventually wrecked. A hub or a BB is a good place for needle or cylindrical bearing: a chain stay pivot is not.

A Double Row Angular Contact (DRAC) bearing is narrower, simpler, is more rigid and has almost as much load carrying capability; plus DRAC bearings can handle both radial and axial loads. We use very high quality INA DRAC bearings in our main pivots (4 of them) which costs a LOT more money (like 5x) than the double stacked single row radial bearings that seem popular these days, but is very bad from a design standpoint). The INA DRAC bearings work for a long time and are very very rigid laterally.

Cheers!

Noel

 

[dhkid]

Its probably because the bearing is designed to work under load...

woops, i fogot to mention they were for santacruz bikes, used in the blur, nomad, vp-free and v10. you still feel a lil bit of play when its on the bike too.