Originally Posted by
Retro Grouch
So how do you measure it? Maybe one of the folks who responded "incorrect" can tell me.
When you take one out of the box they generally look like the left spindle is longer. When you install it in the bike, however, the bearing cartridge doesn't go all of the way to the left side of the bottom bracket shell.
I guess that you could install the bottom bracket and measure from the shell to each end of the spindle but I've never cared enough to do that. If, after installing the crankarms, they spin approximately equi-distance from the chainstays that's close enough for me.
The offset is generally fairly small 2-3mm, such the the left side crank is placed further out. The intent is that you could put a 1-2mm spacer on the right side to adjust your chainline.
This practice was more common when the brackets had alloy cups vs the plastic ones.
The Barretts manual that I have has a chart showing the relative offset of the Shimano brackets.
As to the OP's question, you can't go wrong with a cartridge. Less mainteance, easier to setup. You might be suprised at how easy the fixed cup comes off. I had a 20 yo Peugeot and a 30 yo Raleigh that took no more than good sized monkey wrench to remove.
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