2 years ago, I had to replace the bottom bracket on my vintage Schwinn road bike. It was ancient and horribly seized and rusted and ultimately, getting it out required a hacksaw blade and destroyed the threading in the shell. I replaced it with a Sunlite self-threading bottom bracket and was back on the road for about a year, when the spindle of that new bracket cracked completely in two. I wrote it off as a one-off defect, swapped in a fresh BB, and was good to go again.
It’s now almost exactly a year later and the same thing just happened again, the spindle cracked in half.
Is there some mistake I could be making in the installation that would cause such a massive failure? Do I go ahead with a third BB of the same style? I love this bike but it's not sustainable for the BB to be a yearly consumable and a risk for breaking at any moment.
Possibly relevant: this is my commuter bike in the US Northeast and it lives outside and is ridden daily all winter.
Appreciate any input!
by GeneralMarbles
8 Comments
Are you by any chance rocking some massive watt cannons?
1. How many miles do you ride daily?
2. Where is the bike stored?
3. Is the seat post perhaps fluted? If yes, this might the culprit as it easy for water to penetrate through that gap of each flute.
For people commuting a lot, changing a bottom bracket each year can be a thing.
Was that cracked area of the spindle already rusted when your crank arm fell off?
Worth upgrading to a Shimano BB vs yst
what you are experiencing is not common, not even uncommon,,, it is super rare
the amount of rust makes it seem like it corroded from the inside out..
a quick search did not bring up any recall, but it sure looks like a bad batch of steel made it into production
are your threads so damaged that a bb tap tool can’t clean up the threads? show us a pic of the BB shell threads so we can gauge wether or not tapping can fix them and then you can try a different brand of BB
> Possibly relevant: this is my commuter bike in the US Northeast and it lives outside and is ridden daily all winter.
Absolutely relevant. From the rust, it’s clear that that spindle was cracked for weeks or months before it snapped. This is a fairly strange failure, but clearly this being a persistent problem for you means that you need to purchase a very high quality square taper spindle (Tange, Shimano, IRD) *AND* you need to inspect it regularly.
Alternatively, you could make the switch to an outboard bearing crank and bottom bracket such as Shimano Hollowtech. I’m a big fan of square taper personally, but if this kept happening to me, this is the route I’d go. The larger aluminum spindle will do much better in salty northeastern winters, and the increase in surface area would be an improvement for what appears to be a Rider of Substance such as yourself.
that’s a massive amount of corrosion. You need to start rinsing off your bike and at the least cover it.
you need to also inspect that frame too.
/USACycling has entered the chat