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Bottom bracket

By daveh - Posted on 07 March 2012

The Shimano press fit bearings in my bottom bracket need replacing and I have no issue with actually being able to complete this procedure. My question lies with the correct bottom bracket/bearings. Some articles make it sound like BB86/90/92 are the same but called different things because of the lip on the cup being included in the measurement. My bikes takes is listed as BB86 but does that mean I can buy a bottom bracket for BB90 and it will fit? Preference is to buy the bearings and plastic sleeve that goes around it as its also looking very tired.


Hey Dave

Don't you have the Avanti Cadent? I've replaced mine and I'm pretty sure I just went to ABC bearings.


Thanks Brian, I do not have an Avanti Cadent. Is that the mob at Brookvale? I assume that they are ok with just buying a two sets of bearings rather than in bulk?

They are. I'm trying to think what bike I got bearing from them for. I can't remember if it was the Cadent or the RZ140. I know if the BB bearing is just that and not a fancy shape (if you know what i mean) then they just go off the code on the face of it.

They sell them per bearing so no, you don't have to buy in bulk.

I'll bang it out and take it down with me. Seems to be pretty standard with a Shimano part number and, if I have no luck, it's only down the road. Thanks agan.

Talking of BBs, does anyone else have to replace their shimy BSA68mm BB every year or so? I'm kinda not so happy with these as my mid 80's cannondale BB lasted 25yrs, but the current version is lucky to last 1-2. Can anyone suggest a tougher BSA compatible BB?

While I'm talking about ailments my rear dérailleur tinkles on the spokes when in the granny gear. I've checked the rim dishing and confirmed the idler wheels are 90deg to the axle in all gears which i checked with a set square in the drop outs, the chain removed and a string holding the idler arm close to its usual position. Should i put another spacer behind the cassette or is there something else to check?

Scott, It sounds like you simply need to adjust your L adjustment screw.Your derailleur is moving to far towards your wheel.

Forgot to mention the L screw is adjusted so that the granny sprocket can just be selected, but i'll double check it though, thanks. Otherwise, all other gears are easily and accurately selectable and i have plenty of tension in the spokes.

Sounds like you will need a spacer, subject to the wheel being dished correctly.Check to see if rear mech is not bent(visually from behind).It is possible that it is, even though you are getting clean engagement in all gears.

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