Keep pedaling
Free Shipping Over $50*

Free Shipping Offer

Get free Standard Shipping with your $50 purchase today! Just choose Standard Shipping during checkout.

Please note this offer is only available to physical shipping addresses in the 48 continental United States (no PO Boxes), and oversize charges still apply on some heavy/large items.

Shimano UN55 Bottom Bracket

USD$17.99 28% off USD$24.99 msrp
Item #: BB257F01
USD$17.99 28% off USD$24.99 msrp
Found a Lower Price?
Availability Please make a selection
Quantity

Shimano UN55 Bottom Bracket

High quality Shimano sealed bottom bracket (square taper). Extra strong Aluminum (not plastic) non drive cup. Please choose width and spindle length.

  • English Threaded
Related Products
These adapters kit allow for the use of ...
Problem Solvers PF30 / BB30 Adapter
Description:
These adapters kit allow for the use of external bottom bracket crankarms (24mm spindles) with newer BB30 and PressFit 30 bottom bracket bearings. Technical´┐ŻDetails Dupont Delrin construction Compatible with cranks from Shimano Hollowtech II or FSA MegaExo systems Not compatible ...
Chris King Bottom Bracket Conversion Kit Chris King ...
Chris King Bottom Bracket Conversion Kit
Description:
Chris King Bottom Bracket Conversion Kit Chris King is proud to offer a solution for your bottom bracket conversion needs. Chris King Conversion kits are precision machined and include everything needed to solve your unique fit issue. Please refer to ...

REVIEW SNAPSHOT®

by PowerReviews
Shimano UN55 Bottom Bracket
 
4.6

(based on 37 reviews)

Ratings Distribution

  • 5 Stars

     

    (26)

  • 4 Stars

     

    (9)

  • 3 Stars

     

    (2)

  • 2 Stars

     

    (0)

  • 1 Stars

     

    (0)

97%

of respondents would recommend this to a friend.

Pros

  • Easy to install (29)
  • Durable (18)
  • Enhances pedaling efficiency (14)
  • Lightweight (5)

Cons

No Cons

Best Uses

  • Mountain biking (16)
  • Road biking (16)
    • Reviewer Profile:
    • Avid cyclist (16), Casual/ recreational (8), Commuter (7)
    • Was this a gift?:
    • No (31)

Most Liked Positive Review

 

5 star rating

Bought this BB and so far it is a winner. Very smooth and more importantly, very strong. I put a lot of downward force on my pedals and this BB is stiff and...Read complete review

Bought this BB and so far it is a winner. Very smooth and more importantly, very strong. I put a lot of downward force on my pedals and this BB is stiff and strong. All my power goes to the wheels.

VS

Most Liked Negative Review

 

Minor problem: loose cap

I've bought 3 of these UN55 units, and on two of them the aluminum cap appears to be loose on the cartridge, by about .020". I made a plastic spacer to...Read complete review

I've bought 3 of these UN55 units, and on two of them the aluminum cap appears to be loose on the cartridge, by about .020". I made a plastic spacer to take up the play. On the third unit, the cap seems to fit neatly. Possibly these were packed with the wrong cap?

Reviewed by 37 customers

Sort by

Displaying reviews 1-10

Back to top

Previous | Next »

 
5.0

Good for the price

By D

from Colorado Springs

About Me Commuter

Verified Buyer

Pros

  • Easy To Install
  • Enhances Pedaling Efficiency

Cons

    Best Uses

      Comments about Shimano UN55 Bottom Bracket:

      Installed on my SSCX commuter, more solid feel than an unsealed bb. Would recommend for the price, definitely better than the un26 option.

      • Was this a gift?:
      • No
       
      5.0

      No fuss bottom bracket

      By Cronometro

      from Wausau, Wi

      About Me Avid Cyclist

      Verified Buyer

      Pros

      • Durable
      • Easy To Install

      Cons

        Best Uses

        • Road Biking

        Comments about Shimano UN55 Bottom Bracket:

        Almost indestructible bottom bracket. Inexpensive and long lasting.

        • Was this a gift?:
        • No
         
        5.0

        Works as intended

        By Gnorm

        from B.C. Canada

        About Me Casual/ Recreational

        Verified Buyer

        Pros

        • Durable
        • Easy To Install

        Cons

          Best Uses

          • Mountain Biking

          Comments about Shimano UN55 Bottom Bracket:

          Great.

          • Was this a gift?:
          • No
           
          5.0

          GREAT Bottom Bracket

          By Dr Tim

          from Northeast, TX

          About Me Avid Cyclist

          Verified Buyer

          Pros

          • Durable
          • Enhances Pedaling Efficiency

          Cons

            Best Uses

            • Mountain Biking
            • Road Biking

            Comments about Shimano UN55 Bottom Bracket:

            This is a great bottom bracket. I have ordered two of these now. The first one I put on my Mountain Bike. It now has over 1000 miles without any problems at all. The second one, I put on a bike that I am restoring.

            • Was this a gift?:
            • No
             
            5.0

            Great Replacement Bottom Bracket

            By Dr. Tim

            from North East, TX

            About Me Avid Cyclist

            Pros

            • Durable
            • Easy To Install
            • Enhances Pedaling Efficiency

            Cons

              Best Uses

              • Mountain Biking
              • Road Biking

              Comments about Shimano UN55 Bottom Bracket:

              The Shimano UN55 Bottom Bracket is an excellent replacement bottom bracket. I have uses the UN55 on several bikes that I've upgraded and restored. One of them I ride regularly and have over 800 miles on the UN55. I highly recommend this bottom bracket.

              • Was this a gift?:
              • No
               
              5.0

              Great upgrade for 1999 Trek 6500 MTB

              By ek

              from Ahia

              About Me Commuter

              Verified Buyer

              Pros

              • Aluminum Cup
              • Easy To Install
              • Enhances Pedaling Efficiency

              Cons

                Best Uses

                • Mountain Biking

                Comments about Shimano UN55 Bottom Bracket:

                With my limited bike knowledge, took some time scratching around to determine the UN55 was correct replacement.

                • Was this a gift?:
                • No

                (0 of 1 customers found this review helpful)

                 
                4.0

                Solid part, very smooth!

                By Frazinator

                from Guelph Ontario

                About Me Avid Cyclist

                Verified Reviewer

                Pros

                • Easy To Install
                • Enhances Pedaling Efficiency

                Cons

                  Best Uses

                  • Road Biking

                  Comments about Shimano UN55 Bottom Bracket:

                  This is an awesome bottom bracket for fixed gear bicycles, I bought it to go with a pure-fix crank and they work well together (ie. Square taper). The only thing I would say negative about it, which applies mainly to track/fixed bikes. I had a friend who's chain snapped and in that process (including a bail) the bottom bracket bent a tiny amount, but was barely enough to notice while riding.

                  • Was this a gift?:
                  • No
                   
                  4.0

                  Good product at good price

                  By markw

                  from Charleston, SC

                  About Me Avid Cyclist

                  Verified Buyer

                  Pros

                  • Easy To Install
                  • Enhances Pedaling Efficiency

                  Cons

                    Best Uses

                      Comments about Shimano UN55 Bottom Bracket:

                      Bottom bracket on road bike finally wore out, this was easy to install and greatly improved peddling.

                      • Was this a gift?:
                      • No
                       
                      4.0

                      Execellent Easy to Install

                      By Dean

                      from Moberly, MO

                      About Me Casual/ Recreational

                      Verified Buyer

                      Pros

                      • Easy To Install

                      Cons

                        Best Uses

                          Comments about Shimano UN55 Bottom Bracket:

                          I used this to replace the cheap factory FSA that was a heavy steal consturciton, yet quickly (under 500 miles) developed a grating sound while cranking hard up hills. Though I am a heavier rider at 210lbs and am riding a low end bike that's just one step up from buying one off the shelf at Walmart. Installation was easy, only had to do a minor adjustment on the high and low stops of the front derailer as the offset was slightly different on the drivetrain side from the FSA bracket. Pedalling feels smoother after around 200 miles on the new bottom bracket than it ever did on this bike before. Happy so far with this product.

                          • Was this a gift?:
                          • No

                          (1 of 1 customers found this review helpful)

                           
                          4.0

                          Good fix to worn cup and spindle bb

                          By Gr1m

                          from Cape Cod ,MA

                          About Me Avid Cyclist

                          Verified Buyer

                          Pros

                          • Easy To Install
                          • Enhances Pedaling Efficiency

                          Cons

                            Best Uses

                            • Road Biking

                            Comments about Shimano UN55 Bottom Bracket:

                            I've used this bottom bracket a couple times to replace pitted and rusted spindles. Very easy installation and reliable. Although, I do like my RaceFace external bearing bb a little better.

                            • Was this a gift?:
                            • No

                            Displaying reviews 1-10

                            Back to top

                            Previous | Next »

                            Jenson USA ships worldwide, including APO/FPO addresses. For a quote, simply add the items you are interested in to your shopping cart and look for the "Shipping Options" box. You don't have to login or create an account to see shipping charges.

                            Some manufacturers restrict where we can ship their products. If this item has shipping restrictions, they are listed below. If you'd like to buy an item that we cannot ship to your preferred address, we can accept your foreign credit card and ship to a USA address for you.

                            Get free shipping with your $50 purchase today when you choose Standard Shipping at checkout. Please note this offer is only available to physical shipping addresses in the 48 continental United States (no PO Boxes), and oversize charges still apply on some heavy/large items

                             

                            Free Shipping Offer

                            Get free Standard Shipping with your $50 purchase today! Just choose Standard Shipping during checkout.

                            Please note this offer is only available to physical shipping addresses in the 48 continental United States (no PO Boxes), and oversize charges still apply on some heavy/large items.