Washer on the drive side of Shimano UN300 BB?


Retro Guru
HI guys,

I just got a new bottom bracket for my Peugeot and I noticed there is a washer on the drive side of the axle. I can't imagine what the purpose of such washer is. Do you know?



Retro Guru
According to SJS Cycles it is a limiter. I'm guessing it's to stop the chainset going too far on to the spindle and having a chainring rubbing on the chainstay. Somebody asked the same question on the SJS web page linked, "Plastic/Metal Ring On Axle".


Dirt Disciple
So presumably with this in place, if you can't get your crank to tighten on the taper it's deemed "worn out" and they suggest you purchase a new one? As opposed to a "lesser" BB without the washer, where if you find your inner ring grazing the stay (because it's been worn/abused/overtightened over the years but not rounding out) you just go to a slightly longer BB axle to space it out again...