1985 Trek 560 BB question
 

I was planning to clean and regrease this bottom bracket, but now that it's clean, I notice some minor pitting or spalling in the races. The bearings themselves look perfect.

Is this BB likely to run smooth if I repack it? This is the first time I've taken one apart for maintenance.

I figured I would ask you guys before I reassembled the thing, since you might advise me to replace it instead.

If I do need to replace it, does anyone know offhand what BB I should order?

Thank you

Cups with pitted races are toast-- the spindle may spin marginally smooth after repacking but the pitting will only worsen with time. Time to replace the cups or just upgrade the entire BB unit with a modern cartridge unit.

If you really want to maintain the original spindle (provided its races are in good shape) you can just replace the cups for about $20/pair (check amazon). But for just a few dollars more you can get an entire cartridge unit that'll spin like buttah (look for a Shimano UN54 or UN55)

As for size of BB to replace it with, if you intend to keep the same cranks, order a BB with the same spindle length (measure end to end not including the crank bolts). However, the original spindle is likely offset to the drive-side by a couple of mm, whereas a cartridge unit will be left-right symmetrical. In this case, get a 1-2mm spacer to space out the cartridge unit to the right.

Good luck!

It should work fine I would advise you replace the bearings altogether realatively cheap under $10 for a nice set of raced bearings $4 if you go loose ball with 11 1/4inch bearings on each side. Also as said a cheap sealed BB can be had for about $15-20.

Thank you! Just what I was looking for.

You'll need to know a spindle length as well, if you go the replacement cartridge route. IIRC the Cyclone (if you have the OE crank) works with a 115mm Shimano unit, but I would doublecheck by measuring your existing one.

Cartridge unit. There's nothing like maintenance free, and completely sealed. Unless a bike is so collectable you wouldn't ride it much anyway, that is.,,,,BD

thanks everybody, I replaced it with a 115mm UN55.

Nice choice, those hollow spindle models are much lighter than the standard solid ones.:),,,,BD

My god, it's full of butter.

hahaha....!,,,,BD:D

Seriously though, wait for the first long ride. The difference is astounding. Especially if the existing BB was badly worn, or dry. Power transfer becomes more efficient, and spinning becomes easier.