I have a Shimano Bottom bracket thats taken a crap. Need to upgrade. This bike is going to take a LOT of abuse. I would like to know which models are superior and will still fit the shell. Original model number: Shimano BB-LP27Shell width 68mmAxle length 110 mm (though my eye says 112, could be a crappy ruler)spindles square taper, with a hole bored in the center to allow bolt for mounting cranks. english threadingWhat matches? Please be specific, I need the correct model numbers and brands to order. JB
shimano # bb-un54 68x110. go to a shop and look at all the aftermarket bb's available.
For anyone else coming across this question recently (Summer 2015), the BB-UN55 is essentially the same thing as the UN54, but with an alloy NDS cup instead of plastic. You can find it on sale for under $20 pretty often, but it s only $25 at full price. If you re using your bike for any kind of off road riding, don t get the 54 now that the 55 is an option.
Shimano Un54 Bottom Bracket
The UN54 is Shimano's best current replacement for sealed, square taper bottom brackets. It would be an upgrade over the cheaper LP27 you were riding. The UN54 is a good, reliable BB for not much money, though some people aren't nuts about the plastic adjustable cup. IRD offers their QB55 and QB75 as a suitable upgrade. The QB55 is barely more $ than the UN54. The QB75 is a bit lighter and costs $40+. Sugino offers a similar product, too. Any of the above would be better than what you had. Top upgrades would be from Phil Wood and White Industries. Over $100. Besides getting the correct width (68mm) and spindle length (110mm), make sure your replacement has the correct taper. For most bikes today, this would be JIS. Some euro bikes may have ISO taper.
