Shielded bearings

[Knowledge]

Hi,

Stuck in the office but need to order some front wheel bearings. Has anyone got the measurements to hand?

Thanks, Martin

[Knowledge]

I have found what I want. 6201 2RS.
https://www.rapidonline.com/Mechanical-Fastenings-Fixings/UBC-Bearing-6201-2RS-12mm-Bore-Deep-Groove-Roller-Bearing-6950-N-3100-N-58-3518?IncVat=1&utm_source=bing&utm_medium=cpc&utm_campaign=Temp%20Shopping%20Campaign&utm_term=1100610324255&utm_content=Ad%20group%20%231

I wanted the integral seals for my new custom hub.

[swissdean]

Thats got me interested, firstly because cheap as chips but also has an inbuilt seal..i therefore assume you could lose the rubber seal normally fitted on each end of the hub?

[HxPaul]

Even though the sealed type are supposed to keep all the grease in,if I were you I wouldn't rely on it by omiting to refit the oil seals.

[Knowledge]

I have run a hub since 2009 with shielded bearings in my custom hub, and there are no issues. The grease stays put.

The other advantage for me with a home-built hub, is that as you don't need to allow for thickness of the tradition seal on each side of the bearings, you can space the bearings that much further apart, making the hub more stable on the axle.

I also run a shielded bearing on the drive side of my engine. I pop out one of the integral seals and fit it so that the gearbox oil can still lubricate the ball bearings. This has proven invaluable when used alongside the usual seal, as I have removed from engines traditional drive-side oil seals that have completely failed, but the engine has performed as if nothing was wrong. Result.

[Tractorman]

You could use metal shielded bearings in the front hub rather than rubber sealed ones. These keep both water and dust/grit out.

[Warkton Tornado No.1]

There are three main types of common deep groove ball bearings:

Open (as fitted by Innocenti with back up seals)

With a rubbing seal (one side or both, but 'both' is supplied grease lubricated) example: 6201 2RS

With a non contact shield (one side or both, but 'both' is supplied grease lubricated) 6201 2Z

I have used the shielded for in excess of thirty years with no other seal. They are fine & contribute to reduce drag/friction. I have even used 6201 Z with the single shields to the outside with no issues, but prefer the 2Z type assembly nowadays.

If you leave the normal seals in place with either of the last two options, they will need lubricating just to, erm, rub & seal nothing in as the bearings make them redundant....

[Phil D]

Hi Knowledge Im a bit confused when you say "home built hub " do you mean opposed to built by a say a scooter workshop and isnt there a metal spacer tube between the two bearings. Im really interested as Im in the process of gathering parts /pieces for a project Im working on I did wonder about omiting the seal the last hub I built ,would it be possible to post a photo.regards Phil.

[Knowledge]

H Phil,

Thanks for your interest. I might be able to take a photo of the hub, but it is an awkward thing to capture in a photo. I have had a look for my Mk1 prototype hub, but I can't seem to find it at the moment.

In short, I have made a short (less than 5") axle of 50mm diameter from billet ali. I have machined a 20mm hole through the centre along the axis, and then machined a recess at each end for the two shielded bearings. On the outside, I have machined an 8mm slot for a rectangular section key.

Onto this axle I slip-on kart components, which are both beautifully made and quite cheap, and have a groove for the key already machined into them. The kart components I use are a brake disc carrier and a suitable kart disc (currently 210mm diameter), and a kart sprocket carrier to which I bolt a doughnut of ali plate (approx. 250mm OD) which acts as a spacer between the sprocket carrier and the scooter wheel.

My hubs do have a steel tube within, acting as a spacer between the two bearings. This is essential, but it doesn't need much grease by way of lubrication, more of corrosion protection.

If I can find something to photograph, I'll post it.

[Phil D]

Thanks Martin
Its really fascinating its just hard to visualise Its hard to explain but I find things easier to understand when I can physically see and handle them.
Reading your earlier post
I'm wondering instead of using the 6102 original size bearing would a wider type bearing (if available?) taking up the space that the oil seal originally took up spread the load better that way I could keep the stock spacer and do away with the redundant seal ?

[Knowledge]

I am trying to recall if the original hubs have a circlip in them. If there is no circlip, then a wider bearing could be fitted, but I doubt if you would find one, The width of the bearing is dictated by the size of the balls, and there is only space to fit a certain size ball between the 12mm ID and the 32mm OD.

I posted a photo above, just because I could

[Phil D]

Thanks Martin got it now.
Ive got some parts kicking around from a twist and go that I liberated from a burned out wreck and its certainly got me thinking
on the original
I don't remember seeing a cir-clip but I think there's a step will have a look just had a thought there's nearly room to put two bearings either side?

[HxPaul]

Theres a circlip that has to be removed so that the outside bearing can be removed from the drum.