My daughter was given a Trek 800 Sport in very good condition except for a very growley(sic?) bottom bracket. The spec sheet on this bike lists it as a VP-BC55P 68X122.5 semi cartridge bearing. Googleing this I found that many bikes in this price range used this component in the 2000-2005 years,but I'll be damned if I can find out who made it.I can find several replacement cartridges(Shimanos) that fit the specs,and was wondering if these would be adequate replacements-after all, the crankset is a Shimano. Being an industrial mechanic (printing presses to be exact) the mechanics of removel and replacing it are not daunting,and the web is full of info on how to to do it (once I buy a bb replacement tool)- but I can't find any info on how to spec out a replacement. Any input on this would sure be appreciated.Thanks.
Look for a Shimano 68X122.5 UN-53 cartridge bottom bracket. The UN-73 has a hollow spindle, so it's a little lighter. It costs quite a bit more, though. You can get a comparable Tange brand BB from Bike tools etc. Tange makes them both, anyway.