Bottom braket failure shortly after overhaul. Is this reasonable?

[Deleted member 26715]

I cant understand what has happened from the pic...

No neither can I but there are other people who claim they know exactly what happened & it was the OP's fault for not checking it before he rode.

 

[Illaveago]

From what I can make out from the picture it seems as though the BB axle shaft has sheared off just where the bolt ends. If that is the case then it would appear to be faulty manufacture.

 

[Racing roadkill]

I’ll hazard a guess that they had issues with the self extractor, tried to get it out using a scaffolding pole as leverage, either it did come out, but not without weakening it badly, or they didn’t manage to get it out at all, but still said they’d ‘serviced’ the BB ( they couldn’t have ). They then either re used the weakened self extractor, that they had removed, or damaged it in a failed attempt to get it out, and it then sheared. Looking at the bearings in the photo provided, it looks suspiciously like those are not new, so possibly they didn’t actually get the crank out at all. All questions the OP maybe needs to ask the shop. If I ever have to resort to using a shop to do a job like that, I always insist on having the old parts back, and the packaging for the new bits. Another possibility is that they did what they said they did, and a new self extractor bolt was used, but it was a ‘dud’ and failed prematurely ( for whatever reason ). It’s another good reason for me not to use ‘hands unseen’ to do a job like that.

 

[Yellow Saddle]

I cant understand what has happened from the pic....
Has the spindle snapped and part of it is still in the crank ?

Ignore everything in the picture other than the bit in the bottom right hand corner. That's the spindle-end of the crank, seen from the frame side of the crank. The curly-wurly bit is the splined crank spindle head that broke off in the matching splines of the crank.
The silver dot on the inside of the curly bit is the crank extractor nut.

Look at the left crank in this picture. See the silver crank nut in the middle? Now imagine the end of the crank spindle (on the right hand crank), having broken off and lodged inside it's recess in the left crank.

What had happened is that the crank axle, made from aluminium, had broken off.

 

[Yellow Saddle]

From what I can make out from the picture it seems as though the BB axle shaft has sheared off just where the bolt ends. If that is the case then it would appear to be faulty manufacture.

NO.

 

[Al Bondiga]

Is that a BB30/PF30 type? The crank is usually held on by a large bolt in the centre. Dud it break or just back out?

BB30 type. I took the bike back into the shop and they were able to reattach within 10 minutes. They did not give me an explanation about what they did. I think they felt they may be responsible so they just wanted to fix it and get me out of there.

 

[Yellow Saddle]

The plot thickens. Did the crank break or just come loose?

 

[CXRAndy]

What we tend to do in the UK is accept crap happens sometimes. 600 miles later would be one or two months use. Anything could have happened during that time.

 

[Ajax Bay]

Have you taken the chainset off yourself and looked? Are you sure the left hand crank is the same one as the one you had the failure with? (ie might the bike shop have swapped a 'spare' (used) one in? Having suggested that, that's too much conspiracy when l'actualite is generally 'cock-up'.

 

[robgul]

Looks like this thread is going round in circles with nuemrous therories (me included) - for a once-and-for-all answer the OP needs to post pictures from different angles of : the LH crank and any loose bits and the RH crank with the axle splines clearly visible end on and side on - together with the make and model (if that's know) of the crankset. That SHOULD then make it clear to give an accurate answer.

[Somewhere on the interweb there are some exploded diagrams of FSA cranksets, which look the offending article, that will make it clear]

Rob

 

[Ajax Bay]

exploded diagrams of FSA cranksets

Is this any use?

 

[robgul]

Is this any use?
View attachment 487821

That crankset has pinch bolts (just visible in purple) and a retaining cap (in purple) and there is normally a small safety plate between the pinch bolts that engages in a hole in the axle splines (that's on Shimano) - the OP's crank appeared to have a self extracting crank and not have the pinch bolts?

Again pix as suggested from the OP are necessary

Rob

 

[Al Bondiga]

they were tights, thx

Best advice is usually not to wear pants when you're riding in cycling kit.

 

[Al Bondiga]

I cant understand what has happened from the pic....
Has the spindle snapped and part of it is still in the crank ?

Yeah, I should have added more pics. The crank arm flew off.Looks like the ball bearings broke open, too. I went back to the bike shop that did the work and they said that the bearings are inspected, and if they look fine they are wiped clean and reinserted. They were able to add new bearings and reattach the crank arm pretty quickly. I have not been able to ride the bike since the repair due to wrist injury from the fall.

 

[fossyant]

That's a better explanation - though the crank arm shouldn't have come off - not torqued by the shop. Bearings would possibly pop out if press fit.