Shimano BB bearing swap

dennisn

So I had a bit of money burning holes in my pockets. Found a good deal on Enduro ceramic bearings so thought I would give it a shot at swapping then into my DA7800 bottom bracket.
Shimano bearings have a plastic sleeve that, apparently, prevents the crankset axle from coming in contact with the bearing itself(no metal to metal). Now the Enduro bearing wants to fit somewhat snug onto the axle(metal to metal) and apparently does not use this sleeve. Am I correct so far? The Enduro bearing does come with a couple of snug fitting seals which I assume sort of replace the Shimano sleeve??? A total of zero instructions came with these new bearings. Is metal axle surface to metal bearing surface correct? It would seem that way. As opposed to the way Shimano does it, with a plastic sleeve?
Also, is there an inside and outside face on these Enduro bearings?
Could also use a hint on getting the old bearings out of their shells. Short of coughing up 100 dollars for the gear puller / setter .

Thanx,
Dennis

Monty Dog

Metal-to-metal on the spindle is fine, just make sure it's clean and greased/anti-seize applied. Presume you mean the plastic 'top-hat' as Shimano bearing sleeve which simply pushes into position. If you're not planning to re-use the Shimano bearings, simply drift them out e.g. using a suitable wrench socket, but the force usually damages them. Bearings can be symmetric/assymetric - if it has a chamfer on the bore on one side, then generally this faces out

jermas

The bearings are awkward to press out because there is a ring inside the cup that is the same diameter as the bearing-therefore making it difficult to just use a socket. Careful use of a punch would work as you aren't reusing the bearings. I press them out using a carefully positioned washer placed behind the bearings (the washer is cut on one side, then opened slightly behind the bearing).
Use some heat on the cups (v gentle blow torch or the oven). This makes them a lot easier to press out.

dennisn

Thanx for the info guys. One more issue though that I forgot about. The ceramic bearings come with a set of washers / seals that are metal on one side and rubber on the other. Which side goes against the bearing?

Starting to discover that maybe, just maybe these bearings just aren't worth the money or the effort. I'd better add at least 5 MPH to my rides.

Monty Dog

Bearing seals - rubber on the outside (same as SRAM GXP) plenty of grease between the seal and bearing

dennisn

Monty Dog wrote:

Bearing seals - rubber on the outside (same as SRAM GXP) plenty of grease between the seal and bearing

Will do. Provided, of course, I'm actually successful at getting the old bearings out without destroying the cups.
I'm about to take a swing at them with the proverbial nine pound hammer and chalk it all up as a lost cause. :oops: :x

crankycrank

Instructions here as well. http://www.enduroforkseals.com/sitebuil ... tech2a.pdf Obviously you don't need their special bearing R/R tool but this shows the direction and seal position for the bearings. When you install the new bearings put them in the freezer for a couple hours beforehand and heat up the cups in boiling water. They should slide in much easier.

ugo.santalucia

Shimano BB bearings are 37 x 25 x 6... the standard size is one mm wider... can you find Enduro bearings 6 mm wide?

jermas

The enduro bearings are 37x24x7. They don't use a top hat so are a slightly different size to Shimano.

dennisn

crankycrank wrote:

Instructions here as well. http://www.enduroforkseals.com/sitebuil ... tech2a.pdf Obviously you don't need their special bearing R/R tool but this shows the direction and seal position for the bearings. When you install the new bearings put them in the freezer for a couple hours beforehand and heat up the cups in boiling water. They should slide in much easier.

Excellent. Exactly what I was looking for and wanted to know. Many thanx. I can understand how that bearing extractor
works and may even be able to duplicate the process of getting the old bearing out without purchasing the actual tool. Wish my machinist Uncle was still alive. He could no doubt copy that tool in short order.