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    • Shimano UN55 Square Taper Bottom Bracket

  • Shimano UN55 Square Taper Bottom Bracket

    An ideal option for many bike types with square taper type chainsets, Shimano’s UN55 bottom bracket will give you long lasting, smooth operation mile after mile. Built with accurately machined bearings that rotate inside a sealed cartridge, it prevents any water or dirt ingress. This means it requires no maintenance so you can keep riding smoothly on every ride.


    • Type: Threaded square taper
    • Compatibility: All square taper type chainsets
    • 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

    Manufacturer Reference Numbers:

    • 68x107mm: BBUN55B07; 68x110mm: BBUN55B10-K; 68x113mm: BBUN55B13-K; 68x115mm: BBUN55B15; 68x118mm: BBUN55B18; 68x127mm: BBUN55B27; 73x107mm: BBUN55C07; 73x110mm: BBUN55C10; 73x113mm: BBUN55C13; 73x118mm: BBUN55C18; 73x122.5mm: BBUN55C22; 70x107mm: BBUN55I07; 70x110mm: BBUN55I10;  70x113mm: BBUN55I13; 70x115mm: BBUN55I15

    A 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).

    Buy Shimano Footwear from Chain Reaction Cycles, the World's Largest Online Bike Store.




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