Holy Crap! I feel sick ...

[ColinJ]

I have been working on my Basso, trying to get it ready for a very hilly 110 km audax ride on Sunday - Spring Into The Dales.

My bottom bracket has got some play in it. I thought I'd just check that it hadn't come loose - it has Italian threads so that was always a possibility.

When I took the left crank off, I saw something which made my blood run cold ...

On the last ride I did on that bike I hit 50 mph on some descents and went into a lot of fast bends putting all my weight on that crank!

Sunday's ride includes quite a few steep hills that I will be standing up to climb and more very fast twisty turny descents.

That crank could have snapped off at any moment! I broke one years ago but I was sitting down and only riding slowly at the time.

I'm feeling sick to contemplate what might have happened ...

It was 12 years old and had done a lot of miles but I'd never thought to inspect the cranks. I'll add that to my list of regular bike maintenance tasks for the future and I suggest you do the same!

One question - are all Campagnolo square-tapered bottom bracket axles compatible with each other? I assumed that they are so I only bothered to check the width and thread type when I bought the bottom bracket. Now I'm wondering whether I'd forced the crank onto an axle that was too big?

 

[Maz]

Very, very close call. Scary.
Glad you caught that just in time!

 

[MartinC]

All Campagnolo square taper cranks/BB's are ISO so they all interchange. Cranks sometimes fail like this and Campag ones are no better in this respect. You're really lucky you found it in the shed and not on the road.

 

[raindog]

That looks almost identical to mine
https://www.cyclechat.net/
what quality Campag is it?

 

[Berlinbybike]

what quality Campag is it?

I think the answer to that is "poor quality."

 

[Zoiders]

I got home the other night and found the locknut/spacer on the fixed hub had split and dropped off when riding.

Effectively only one tracknut was holding the wheel in, I am not sure how I avoided the wheel locking up and trying to fold me and the bike in half.

 

[GrasB]

I think the answer to that is "poor quality."

That's to be expected with square taper cranks & I've seen a fair number of relatively new bikes with cracks in the arm like that - Shimano, Suntour & Truvativ. I've also heard of Miche & Sugino with cracks in too.

 

[ColinJ]

All Campagnolo square taper cranks/BB's are ISO so they all interchange. Cranks sometimes fail like this and Campag ones are no better in this respect. You're really lucky you found it in the shed and not on the road.

Thanks and I agree!

That looks almost identical to mine
http://www.cyclechat...-cracked-crank/
what quality Campag is it?

Old Athena which became Daytona which became Centaur.

I think the answer to that is "poor quality."

It was well-made but I think square-taper is a poor design. It is so obvious that the act of tightening the crank on is trying to split the hole open.

That's to be expected with square taper cranks & I've seen a fair number of relatively new bikes with cracks in the arm like that - Shimano, Suntour & Truvativ. I've also heard of Miche & Sugino with cracks in too.

See - GrasB thinks so too!

 

[GrasB]

It was well-made but I think square-taper is a poor design. It is so obvious that the act of tightening the crank on is trying to split the hole open.

One reason I like BB30 over 'standard' external BB setups, though they're not as bad as square taper cranks they still have sharp edges which are forced apart by torquing down the cranks. If you look at a BB30 crank you'll see that the sharp edges are forced together by the taper. It kind of erks me when people complain about external BB & BB30 being 'needless money making upgrades' to square taper BBs, both solve fundamental problems with the square taper format.

 

[HLaB]

I just took of my mudguards, they were cracked; I'm off to check the cranks whilst the bike is still in the workstand! The most I get to is around 38mph but even at that speed it'd be scary!

Phew my cranks are fine.