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UN55 Square Taper Bottom Bracket

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  (3 customer reviews)
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MSRP $23.99
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It's hip to be square.

With the Shimano UN55 Square Taper Bottom Bracket, you get a highly durable, smooth-rolling bottom bracket for threaded bottom bracket shells and square-tapered cranksets. The sealed bearing cartridges keep water, dirt, mud, and road grime from penetrating the unit, keeping your bottom bracket rolling grind-free for seasons.

B-Stock - This product has one or more B-Stock units available. These units can be purchased at a discount (see option select). B-Stock units were returned from other customers and may have missing or damaged packaging materials. These units are otherwise as new. The full manufacturer warranty applies. Click Here for more information.


Bottom Bracket STD: English (BSA) 

68 x 107mm

Mfg PartNum: EBBUN55B07 

68 X 113mm

Mfg PartNum: EBBUN55B13 

68 X 115mm

Mfg PartNum: EBBUN55B15 

68 X 122.5mm

Mfg PartNum: EBBUN55B22 

73 X 118mm

Mfg PartNum: EBBUN55C18 

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Quality replacement
by MS

Replaced the same un55 which was 6 years old and ridden through winter roads. Smooth. No noise

Reviewed 8/15/2019
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Worked perfectly!
by Mike
Cycling Enthusiast
East coast

Bought this BB to replace an old school square taper axle on an old Univega. Worked perfectly. I dont know why I even thought about buying replacement bearings for the original set up when this sealed bearing was a better replacement.

Reviewed 2/7/2020
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Perfect in every way
by G.Taylor
Rochester Michigan
5 of 6 customers found this review helpful.

Went on line and ordered the part I needed, screwed up and ordered the wrong one , emailed the bikestiresdirect about my mistake and they could not have been more helpful , understanding and quick to respond to straighten out my screw up and insured my order was correct . Perfect transaction .

Reviewed 3/15/2018
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