Bottom bracket trouble - how worried should I be?

[Donger]

Every time I get a creak from the bottom bracket area I put the bike in for a professional inspection .... ever since this happened to me in 2017 after I ignored the creak for a couple of rides:

I ended up half way across a junction with both pedals aiming downwards. My LBS mechanic had never seen an axle failure quite like it. Creaks now give me the creeps.

 

[SuperGalactian]

Is it possible to arrange to have the bike stationary with the back wheel locked so you can apply pressure to each pedal in turn to see if you can duplicate the creak?

Yes, but pressure via the BB end of the crank, bypassing the pedals. See my OP.

Is the paint cracked on the drive side lug?

Not that I can see. I’ve looked very carefully.

If you have suspicions about any part of the frame try introducing some light oil like paraffin into the area and repeating the creak test - chances are if there's a crack it's quieten down for a bit if lubricated.

Thanks for that idea, I’ll try that.

 

[classic33]

Yes, but pressure via the BB end of the crank, bypassing the pedals. See my OP.

Not that I can see. I’ve looked very carefully.

Thanks for that idea, I’ll try that.

Fair enough, you have the piece to hand to check, I don't. That's my idea out the door though.

 

[SuperGalactian]

Just an update on my original problem. I uninstalled the BB (noting carefully which faces of the square spindle fitted which faces of the cranks), greased the parts that one doesn’t expect to move, then reinstalled and torqued everything up properly. Did 50 miles on Sunday, including some tough hills, without a creak. So in this case, it really was the BB. Thanks to all for advice.

 

[Ming the Merciless]

Every time I get a creak from the bottom bracket area I put the bike in for a professional inspection .... ever since this happened to me in 2017 after I ignored the creak for a couple of rides:

View attachment 818394
I ended up half way across a junction with both pedals aiming downwards. My LBS mechanic had never seen an axle failure quite like it. Creaks now give me the creeps.

Looks like a lot of corrosion going on there. Salty wet roads and spray with no mudguards?

 

[Donger]

Looks like a lot of corrosion going on there. Salty wet roads and spray with no mudguards?

Probably right about the salt, but I've always used mudguards. No excuse for the muck. I never ignore a creak these days. Being a 300 pounder, I take a heavy toll of components, shearing off metal bits for fun, so I never ignore an early warning. I also no longer stop at junctions in the big ring hoping to power my way up to speed in a high gear from a stationary position. In fact, at busy junctions I have been known to dismount and push the bike across the road to make sure this never happens to me again. Once you have come to a standstill in the middle of the road with both pedals pointing South and a car bearing down on you, you tend to become more cautious like that.

 

[SuperGalactian]

Probably right about the salt, but I've always used mudguards. No excuse for the muck. I never ignore a creak these days. Being a 300 pounder, I take a heavy toll of components, shearing off metal bits for fun, so I never ignore an early warning. I also no longer stop at junctions in the big ring hoping to power my way up to speed in a high gear from a stationary position. In fact, at busy junctions I have been known to dismount and push the bike across the road to make sure this never happens to me again. Once you have come to a standstill in the middle of the road with both pedals pointing South and a car bearing down on you, you tend to become more cautious like that.

Until I saw your photo, I had no idea anyone made a BB axle out of hollow tube. What brand was that?

 

[Jameshow]

Until I saw your photo, I had no idea anyone made a BB axle out of hollow tube. What brand was that?

Shimano hollow tech by the looks of it.
But most modern axles are hollow!
Your square taper axle is simpler and more reliable imho

 

[SuperGalactian]

Shimano hollow tech by the looks of it.
But most modern axles are hollow!
Your square taper axle is simpler and more reliable imho

Ah, OK, thanks. I am generally a few decades behind the cutting edge. It never occurred to me, but I guess the Campy Ultra Torque crankset on my 2010 bike also has a hollow axle then?