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Trek BB86.5

timbo_timtimbo_tim Posts: 199
edited September 2017 in Workshop
Hi all

So my trek Edmonda apparently has Trek’s press fit BB86.5 but can anyone tell me if this is the same as a standard BB86 . Trying to work out a replacement but keep reading about BB90 on Treks and nothing about this one. Does 0.5mm make a difference?




  • Thanks PP but I remain confused / stupid! Not sure if Trek’s BB86.5 standard is just another name for 86-seems like they are going on the measurements on that chart, and if so I guess I need to work out the shellID (46 or 41). I cant believe I am the first to replace a BB in an Edmonda but can’t seem to find a clear response out there...
  • dj58dj58 Posts: 2,185
    From the Park Tools website

    Trek® BB90

    The Trek® Bicycle Company uses a proprietary bottom bracket design on some model bikes called the BB90. The crankset system is effectively the BB92 style, however the bearings themselves are different (figure 12). The bearings have no plastic retainer or cups. These bearings are a mild press fit into the bottom bracket shell. The cartridge bearing are 37mm outside diameter and 24mm inside diameter to accept the Shimano® Hollowtech® II cranksets. For SRAM® GXP® cranks, the left bearing has a 22mm diameter.

    The cranks are removed with normal procedures. Use the BBT-90.3 driver to tap out each bearing. The bearing seat inside the shell cannot be removed. ... -section-4
  • The aluminium ALR Emondas use BB86 (aka BB86.5, it's the same thing), while carbon S, SL and SLR Emondas use BB90 (a very different standard).
  • Thanks Rasinberry-exactly what I needed as it is an ALR that I am referring to.
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