I ride a 02 Rockhopper A1 Comp FSRxc and need to replace the bottom bracket. The bb that came on the bike is a Shimano BB-UN-52, square taper, e-type, 68 x 113mm. Of course that bb seems to be history.
If you can find a UN-72 (E-type or not) you can try that. I was able to get away with the non-E-Type on a Haro I had (that had an E-type derailler). It's gonna throw your chainline off a bit but I didn't have any problems on mine.
ANY Shimano UN series bottom bracket as long as it IS NOT E TYPE and is available in 68X113. Anything like an E type of anything larger than 113mm will screw your shifting up. Chain line is critical on FSR bikes, minor differences that you can get away with on a hard tail, you can't get away with on an FSR. So don't ask for trouble. Jenson, Universal Cycles and a few others still have UN-73 BBs available for around $30. If you shop around enough you may even find some UN-72s still floating around. With that said, and Etype can be made to work, but you will need a 2mm spacer between the BB housing and the bottom bracket flange to keep your chain line correct. But there are still non Etypes out there, so why go through the hassle.
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