1970s Dawes Galaxy

[JonoB]

It's fair to say that I am a little inexperienced in these matters but I've just stripped down my 1970s Galaxy. Although the BB is the older type with 2 encapsulated bearing cases and a spindle thing, can I replace this for a modern (lighter) BB - the type that is a sealed unit. Are the sizes different now (metric/imperial)? Can anybody recommend one or should I just clean up and refit the original......... Any help welcome

 

[gbb]

Cant speak for your exact bike Jono, but i upgraded by old loose cup BB on a (probaly 1980s) raliegh 531 for a sealed unit, piece of cake.
Take it to your LBS if youre not sure, they'll have , or tell you which one to get.

Edited to say...i wouldnt bet a standard modern BB is lighter than what you're replacing. Cheapish sealed BBs can be quite heavy.

 

[PpPete]

70s Dawes Galaxy is a standard british threaded BB. (68 mm shell)
Can certainly be replaced with a modern sealed unit - done it myself on several of this age.

Shimano UN54 is often held up as good standard (assuming you have square taper cranks) although the plastic cup is not my favorite.

You can even put Hollowtech II outboard bearings on it - same thread !

 

[JonoB]

70s Dawes Galaxy is a standard british threaded BB. (68 mm shell)
Can certainly be replaced with a modern sealed unit - done it myself on several of this age.

Shimano UN54 is often held up as good standard (assuming you have square taper cranks) although the plastic cup is not my favorite.

You can even put Hollowtech II outboard bearings on it - same thread !

Thanks for this chaps........Just looked for the UN54 on ChainReaction http://www.chainreactioncycles.com/Models.aspx?ModelID=17473
The 68mm is obviously the shell as you say, what the other measurement I need to take?

 

[PpPete]

That will depend on what chainset you are planning to fit.
If you are going to refit the old one, just the length of the old spindle is a good guide .... but beware some of the old ones were asymmetric which complicates matters - google "Sheldon brown bottom bracket" for a database.
If you are going for a new chainset - follow the recommendation of the manufacturer.