SHIMANO UN300 BOTTOM BRACKET ENGLISH 68x122.5mm SQUARE TAPER

Purchased to replace original one in 1980’s rigid frame Rockhopper. Used the 68 x122.5 and it fit fine. It was slightly longer than the original so I had to adjust the front derailleur but it worked out perfectly. Seems well made. We’ll see how long it lasts.

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.

Fits perfectly in my vintage Schwinn traveler and makes pedaling smooth again! Only thing to note is this does not come with the hardware required to attach the pedals.

This ball bearing cartridge definitely is what my bike was missing!! If you measure correctly which one you need, it will make your bike feel like new again!! This bottom bracket easy to install and fit perfectly to my bike !

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.