Sprocket carrier bearings

[AndyB57]

Apologies if this has been covered umpteen times but I have searched the forum and found nothing......

Can somebody share details of the sprocket and cush drive assembly please? I want to replace the bearings but the existing bearings have no markings which Simply Bearings recognise, and I suspect I'll need a bit more insight than I currently have to extract and replace them.

Thanks!

[George 350]

Hi Andy,
For cast wheels, sprocket carrier bearings are code 6004 (20x42x12). I assume spoked wheel carrier has the same but worth measuring yours. Standard C3 spec are fine. Personally I always replace wheel bearings with the pre greased and sealed 2RS level ones, e.g 6004 2RS.

As for removal, tap the centre spacer to one side and drift the bearing out, going from one side of it to the other as you do so that it comes out 'square'.

Regards, George

[AndyB57]

George, thanks very much. I should have mentioned it's a cast wheel!

With a bit more cleaning and better light I can just about make out 42x30x7 on the sprocket side bearing. Does this mean the wheels used have very different specs depending on age?

I'm trying to track down a parts list online......

[mbmm350s]

Hi Andy,

what you can see there is the grease seal. its a single lip seal.
something like this is fine with sealed bearings, please double check the markings, i don't have one to hand to check.
https://simplybearings.co.uk/shop/image ... _front.jpg

If you prise that out you will see the bearing behind.

George already mentioned the bearings. 6004 2RS
Mark

[AndyB57]

That's great, thanks guys.

Like everyone over the last few weeks I guess, what started out as a quick looksee and tidy up has ended up with just about everything mechanical being removed or at least peered into - apart from the electrickery which I'm leaving well alone at the moment!