What are the pros and cons of both? Theoretically which one is better?

Metal has less resistance but lets more dirt in. Rubber seals better, so protects better against dirt, but rubs a little more. So depends on where you drive and where you use the bearing. There are also some hybrid bearings from Avid with one side metal one side rubber for putting in the rear hubs and front knuckles. The metal side goes inside, where there is no dirt.

2 different seals? Then you can better get a normal rubber shielded bearing, take one shield out and put the open side to the inside of the upright

so metal is better for on-road and rubber is better for off-road in essence. seems like that hybrid would still be more for on-road, but to help reduce friction.

i appreciate the input!

Not necessarily. Plenty of offroad guys use shielded bearings and normally clean their bearings (or chuck em after a few runs). Many onroad guys run on dirty tracks and never clean their bearings.

Metal shields are typically cheaper and easier to clean. I have typically been buying tubes of shielded bearings. I only clean them ever so often whenever there is noticeable garbage in them, but chuck em after about a year - or keep them as "give aways" to someone in the pits.

I hate cleaning rubber seal bearings, and often just chuck em if there is noticeable garbage inside.

At the end of the day, the difference in price is minimal between the two.

yea the reason i was asking i was searching for a set of bearings and where i was looking same brand/size/quantity/price and it was rubber and metal hence the question that i raised.

Run your bearings with no shields for on road , and metal shields for off road... If they start catching, then chuck them....

duly noted

Go to Avids website, $1 metal, rubber, or hybrid shielded bearings. I would only worry about the hub, and knuckle bearings. Get $20-$30 worth. Drive the car for a few race days, and just replace as necessary. At $1 apiece it's easier to replace than to take the time and annoyance of cleaning. If you have a car with DCJ's make sure you get a few 5x8x3mm bearings for the inside of the front knuckle. But the 5x8x3 only come in metal shielded from Avid. I bought $40 worth a year ago and have used less than have of them.

Good luck and have fun.

talk about clutch...thanks a million!!

Maybe Im missing something, but how are metal shielded bearings easier to clean than rubber sealed ones? Taking out the shield is 20 times harder than removing the seal.

Don't remove the shields.

I dust off my metal bearings with a toothbrush before I oil, but if the bearing feels grindy or too loose/rattles after the lube, I just toss it.

The rubber sealed bearings have more friction, but they are nearly maintenance free on my on road cars that gets only indoor drive time. They usually come packed with some heavy oil/grease that last a long time.