Its a post full of riddles!!!
"Aha" what do you mean by this? is it right or wrong to use Enduro bearings in a BB90?
Do you mean, the bearings thickness is 1mm "thinner", not 1mm shorter and are we reffering about diameter or depth?
"so you think you can just replace but you cannot" Why cannot you replace?
Why is Enduro a life saver?
"Only some Shimano BBs can be "serviced" like that." "Serviced" like what?
Aha means that you did what I expected. It is an exclamation I expressed after you gave us a bit more info on how you managed to change the bearings in your BB cup. You said you just replaced the bearings but did not tell us how. You cannot just go out and buy a new bearing for the BB based on the code printed on the seal. Bearing codes are universal. For instance, a 6805 bearing has very specific dimensions it has an ID of 25mm, an OD of 37mm and a width of 7mm. This is absolutely standard and all manufacturers use the same code, albeit sometimes with an extra digit in front to indicate one or other proprietary feature of the bearing. Then, the second part of the code indicates the type of seal on the bearing. RS2 for instance means there is a rubber seal on each side of the bearing. RS means just one side and ZZ means it has to metal shields - one on either side.
Now along comes Johnny and opens his BB to replace the bearing inside. He takes the plastic cup off and sees inside that it is an 6805 RS/2 bearing. Bingo! he thinks and goes to the bearing shop and buys two 6805 RS/2 bearings. He fits them and finds that they are 1mm too thick (wide). He double-checks the code and sees that he did not make a mistake, he used the right code. He then measures the old bearing which is marked as 6805 and sees that it is only 6mm wide. Puzzled, he gives up.
What Shimano did is design a proprietary bearing for their BBs which has the same ID and OD as a 6805 but is 6mm wide instead of 7mm. Yet, being devious, they kept the seal (codes are always printed on the seal) that says 6805.
The Enduro bearing company is big enough to also order proprietary sizes and designed their own bearing to fit in there. Enduro is a great system but, the dramatic drop in price in BB cups from Shimano about two years ago means that it isn't really economical to use them anymore.
I said you think you can just replace, but you cannot because of the 6805 coding confusion created by Shimano.
Enduro is a life-saver (not literally) because it gave us an option in the days gone by for servicing a BB cup. By servicing the cup I mean replace the bearing and clean the threads etc.
Only some Shimano BBs can be serviced using the Enduro system. Shimano has two styles of screw-in BB cups and one of them uses a bearing that even Enduro doesn't make.
Does that help?
, well I think we are both correct as my carbon bike and a lot of carbon bikes have a metal insert inside the BB so its not there because of the carbon shell plus the PF is now fitted in some Ally bikes with no carbon .
The other, being a British Eagle was of the traditional BB style and somehow it was a lot more fun. Had to lay the bike on it's side and apply WD40 before I could get the fixed cup out. But then after cleaning the accumulated crap off the frame threads, applying LOADS of teflon grease to anything to do with the unit put in the new fixed cup, bearings and races, axle, l/h cup and play around with said cup and locking ring, the whole thing gave a better feeling of satisfaction.
