Bottom bracket size

[rogerzilla]

The only difference between Shimano and Campag square taper (both considered obsolete by their makers) is that the Campag one starts narrower. They're both 2 degree tapers.

Grease on the tapers certainly affects the chainline - which is hit or miss for ST anyway, given manufacturing tolerances - but once you've had to remove seized cranks where the extractor has torn out of its threads, you use grease.

How does grease affect the chain line?

The cranks go on much further for a given torque on the crankbolt. About 3mm.

[Brucey]

IME the four flats can differ in size and shape considerably. You can have the correct chainline and the exact correct 2 degree taper and still come unstuck. This is why you should try to use matched sets of new parts, or at least 'known good' combinations. If used cranks are to be fitted to any new spindle,you should carefully assess the quality of the fit, as per my earlier post. IME using a simple grease (ie. oil + thickener) during assembly has nothing much to do with how difficult it is to remove the cranks a year or more later; either way, they can have 'cold welded' themselves on, if the pedalling has been sufficiently vigorous. Should you want to suppress corrosion, you can daub on pretty much anything later. Provided the cranks have been ridden on properly, the joint will be consolidated, so that full penetration of any added fluid is unlikely after six months or so. Incidentally, this is also more or less why penetrating fluids don't always work.

[Dupont]

IME the four flats can differ in size and shape considerably. You can have the correct chainline and the exact correct 2 degree taper and still come unstuck. This is why you should try to use matched sets of new parts, or at least 'known good' combinations. If used cranks are to be fitted to any new spindle,you should carefully assess the quality of the fit, as per my earlier post. IME using a simple grease (ie. oil + thickener) during assembly has nothing much to do with how difficult it is to remove the cranks a year or more later; either way, they can have 'cold welded' themselves on, if the pedalling has been sufficiently vigorous. Should you want to suppress corrosion, you can daub on pretty much anything later. Provided the cranks have been ridden on properly, the joint will be consolidated, so that full penetration of any added fluid is unlikely after six months or so. Incidentally, this is also more or less why penetrating fluids don't always work.

I may just put new cranks on as the pedals are new. Spa have sort decent price options.

[fastpedaller]

don't forget some grease on the pedal/crank threads so they don't become seized! Apologies if you are already aware.

[Dupont]

don't forget some grease on the pedal/crank threads so they don't become seized! Apologies if you are already aware.

So, grease the pedal hole but not the taper hole on spindle seems to be the train of thought here.

[fastpedaller]

don't forget some grease on the pedal/crank threads so they don't become seized! Apologies if you are already aware.

So, grease the pedal hole but not the taper hole on spindle seems to be the train of thought here.

Opinions differ of course, but I'm confident we all agree on greasing the pedal threads