What is best? need some 6x13x5mm bearings for my pedals
Rubber will be a little more water resistant.
also thinking easier to get the seals off to put grease in
Depends on the pedals. Some might work better unshielded so you can half fill the body with grease and purge the bearings as you put the axle back in.
I had the same question so I called a bearing supplier. The guy on the phone said rubber shields are used to seal against moisture ingress and metal shields are used for impact protection.
Impact protection? in what context was he talking?
Metal sheilds are generally a bit less draggy but will let more moisture and mud in.
Rubber shields have a bit more drag but offer better moisture/mud protection but can be easily distorted by stuff - eg if you have loads of mud/grit piling up against the side - maybe that is what the guy in the shop meant?
Rubber can be taken out and serviced easily, metal you normally **** up.
[b]Somewhere quite exposed and you want to fit and forget for ages but don't mind if they get a bit ropey as long as they keep spinning[/b] - stainless steel metal sheilded. Yes water will get in but won't rust. Eventually the bearings will wear out but they will be able to survive a lot of abuse.
[b]If you like to be able to service stuff to maintain silky smooth performance or they are likely to sit in pools of quite clean water[/b] then rubber. You can fully flush them and re-grease them if they do get a bit rough but the seals could be damaged if the design of the mechanism allows grit to get trapped against them.
Long story short - in pedals with good sealing and no grease ports I would go with stainless. In pedals with a grease port which you will use then possibly go rubber with the seals removed as mentioned above.
I am thinking that as the pedals have a bearing on the outside end only and bush at the crank arm side i will fill the gap behind the bearing with grease, put the bearing in and do the nut up to hold the pedal on the axle. more grease on top of the bearing and then the end cap
metal shielded with a grease barrier on both sides and then sealed with the end cap? Sounds like a good plan. Any waterproof grease will keep it in check.
Metal sheilds are used only in sealed for life bearings, if you try to remove them they are basically useless after. The rubber seals are designed to be removed but dont use a screwdriver use a seal pick. Their really cheap and don't damange the seal.