samkl 

Noticed some rust on the BB of a fairly new bike, 7 months old with ~1200 miles on it. I took it apart and find it completely corroded! A little pile of rust flakes left in the frame (all from the BB- the frame has no rust at all). Bearings spin, but aren’t so smooth.

I rode this bike in the rain only a couple times, and wiped it down afterwards. Bike is stored indoors too.

I have a Shimano UN-55 with 6000 miles on it and it looked brand new when I took it out of the frame. I don’t want to besmirch Tange BBs’ reputation, but jeez.

fietsbob

condensation happens,, blow out that stuff , "Framesaver" the inside of the tubes put in a new BB..

save the left mounting piece, after you clean it up, and use a cheaper UN 26 , and that piece if you don't like the plastic one.

samkl 

The adjustable cup is maybe the most rusted part of all. After I cleaned it up it was pitted and corroded like you’d expect on a maltreated 20-year-old bike.

Frame has no rust at all, in contrast to the BB.

fietsbob

Condensation rusted the inside un painted surfaces of the steel tubing..

samkl 

I already put the thing back together so I can’t take a picture, but no, the frame had no rust at all. I just wiped away the rust flakes and the frame was pristine inside.

It came from the factory with an anti-rust coating, which might’ve helped.

Point is the BB is pretty low quality.

fietsbob

Spend more to get better https://www.renehersecycles.com/prod...ttom-brackets/

trailangel

Tange is higher quality than the Shimano BBs. You have something going on in there. Water got into your frame. You say 7 months old bike, but I have never seen a bike come with a Tange BB. Who put it together when it was new? BB looks like an older version to me.

3alarmer 

.
...this is also my experience (better quality) with Tange sealed units. There's something else going on, but I have no idea what it is.
If it were me, I'd switch to using a nylon plastic adjustable side retainer, and drill some weep holes in the BB shell while it is empty.

At the very least, I'd probably install the new BB unit with some kind of anti-seize on the threads, if I didn't use a plastic ring.

samkl 

Bike is a Wabi Classic. The BB appears to be a lower end model, with a steel retaining ring and a solid axle.

Also - this is probably relevant - I don’t think it was installed properly. The BB was barely torqued down when I unscrewed it.

trailangel

Hmm. When I search for this BB number it comes up with a TH industries or FSA bottom bracket, not Tange.


Did somebody switch?

samkl 

Nope, I bought it from Wabi.

JohnDThompson 

IIRC, Tange made the Shimano-branded cartridges.