Narrower BB lock nut or just ditch dust cover?

[mikeyrb1]

Just installing a new BBSHD on a fat bike and battling the spacing a little. Got everything dialed except I don’t have enough threads to screw the BB dust cover on. I’ve seen where someone shaved down the lock nut to get enough threads for the dust cover. Is this necessary? Seems like the lock nut is more important than the dust cover. Do they make narrower lock nuts?

[bitnaut]

You probably should have ordered one size larger for your BB ie. if you ordered 100mm version, you should probably try the 120mm instead to get more exposed threads and then use spacers to make up the difference.

[Retrorockit]

You might try using Loctite blue (removeable) thread locking fluid instead of the locknut. The threads will be weak if there aren't a couple bare ones exposed though. So be careful.
It's possible to have a bike shop trim the BB shell with a BB facing tool to gain a little there also. But this only works if the motor isn't already up against the chainstay.

[bitnaut]

Well, strangely enough, I now have the same problem: I ordered the 100mm bbshd for my 2013 Salsa Mukluk but the chain stay interferes with the secondary reduction gear slightly so now there’s only enough thread for the triangular mounting plate and locking nut...not enough for putting on the dust cover.

So, do I just loctite the locknut and forget about the dust cover? Or order the 120mm and screw up the chain line and pedal Q factor not to mention the pain of cross-shipping the 100mm and 120mm motors to China? Ugh

[Janice]

I'm not sure if this is the same issue, but I thought I couldn't get the second nut on unless I turned it backwards. In fact I just needed to push it onto the first nut.

They subsequently got loose so I used Loctite.

[paxtana]

The black ring is not a dust cover, it is a jam nut. Its only job is keeping the gray ring from coming unscrewed. As others have said, a drop of blue loctite on the threads works just as well if you can not fit the black ring on there. This is also recommended in this event in the knowledge base.

[bitnaut]

Yes, in the end, I just used Loctite on the locking nut and it seems to be holding so far after 160km.