SHIMANO Square Type Bicycle Bottom Bracket - BSA 68MM, Spindle: 122.5MM - EBBUN300B22X

If you have an old Trek 750 Multitrack, chances are, this is what you're looking for. Eventually the seals do fail on these, and when that happens after decades of service, it's finally time to get a new one. Thankfully Shimano is still making replacements after all these years. My bike is up and running like new again.Installation is an absolute bear. You will need specialized tools, probably a fair amount of brute force, and a lot of patience. Don't DIY this if you don't know what you're doing. Have your local bike shop install it.

You can't go wrong with genuine Shimano parts. I had a cheap plastic cup one and that lasted a year. This is all metal and works awesome! I had a problem with the tool fitting the notches. That could have been the tool

This is your basic, industry standard, square taper bottom bracket. I’ve brought many old bikes back to life and this is the bottom bracket I’ll use in most of them … usually a triple crankset on a 122.5mm spindle. These are well made, durable, inexpensive, and come in a good variety of sizes . You can save a couple bucks with Brand X, but most of the time I’m using one of these to replace a Brand X piece that has failed. I can take one of these out of the package, apply a little anti-seize, install it, and go on to something else. I haven’t had one fail me yet.

Installed easily using the Teyssor Bike Bottom Bracket Removal Tool.

As an amateur bike mechanic, I did quite a bit of research regarding a replacement BB for my 93 Bridgestone. The original was non sealed and quite worn, so I replaced it with this one. While the drive side fit just fine, the non drive side housing did not thread all the way into my BB. I measured that, and it is 68mm which is what this unit is advertised as, yet no matter how I tried, I'm left with a couple threads sticking out the BB shell. From what I can tell, this is not a problem, but just in case I thought I should report that. Otherwise, its a very well made component and the price is right for sure.

This was a significant upgrade over the old, worn out bearing set in an old Victory road bike that I saved from a neighbor's trash. very smooth action, should last the remaining life of the bike.

As others noted- the width of the fully screwed in cups from the inside of the drive side to the outside of the left side is more like 73mm, leaving 5mm of thread hanging out of the frame. No idea why, but likely has to do with the spindle length. this also means the 122.5mm spindle is not centered in the BB of the frame. Not sure it really matters- but it doesn't look nice.

I got this to replace the crank in my grandson’s bicycle. I highly recommend the unique tool for removing the old one and tightening up the new one. I used a cheap caliper style micrometer I just happen to have to make exact measurements of the old one so I could be sure to order the correct replacement size. Works nicely now.!!!