Washer on the drive side of Shimano UN300 BB?

[Ugo51]

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?

 

[curzons246]

If you search for the shimano dealer manual it gives you chapter and verse. To much to transfer to here

 

[rikster]

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".
https://www.sjscycles.co.uk/bottom-...l-square-taper-bottom-bracket-english-thread/

 

[Ren Rawbor]

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...

 

[Ugo51]

In a nutshell, yes