Shimano UN55 Square Taper Bottom Bracket
Shimano UN55 Square Taper Bottom Bracket
Code: BBUN55
New, uprated square taper bottom bracket from Shimano.
  • A good quality bottom bracket for traditional chainsets
  • Super-accurate bearings for smooth operation and improved durability
  • Durable, hard-wearing sealed cartridge bottom bracket with square tapered spindle fitting
  • Lightweight hollow spindle
  • Maintenance-free sealed cartridge bearing assembly keeps out dirt, mud, and water for long bearing life
  • Fast and easy installation without adjustment
  • Narrow body allows clearance for cable routing under the bottom bracket
Please enter your e-mail address below then click Notify Me to be notified when this item comes back into stock. We will not use your e-mail address for any other purpose.
The following errors occurred:

Please correct the errors and try again


Shipping charges for this item to United States: $6.43

Spend $64.25 or over and get free shipping
$ 6.43
General information about our shipping
A solid, reliable fit and forget unit. I have had a UN54 on my Giant for around 3 years and it only recently started creaking. As usual, a quality product from the Big S.
This Shimano UN55 is a great quality bottom bracket. This is the first replacement bottom bracket for my Trek Pilot road bike it's a good price and was easy to install.(once I'd got the old one out) The unit and the retaining ring are both metal and this was one of my reasons for choosing it. The bike now rides smoothly and quietly, no more crunchy noises! I would reccommend this as it's a well priced product and shimano.
A good basic bottom bracket. Excellent service from Merlin Cycles as usual.
Quick delivery, and good comms.
Old OEM original VP one was rough as a badgers arse after 5 years, this is so smooth in comparison it's transformed the bike.
Replacement square taper BB, no problems at a very good price.