Calling Shimano experts - broken Ultegra 6800 crank

[Daveyraveygravey]

Hi all

Had my second Ultegra crank failure this morning. Well, not total failure, but it is on the way out. I bought the bike in 2015, the original had the same failure after about 3 years. I had a few arguments with Madison who didn't want to replace it because it was outside the warranty, but eventually they saw sense. It is this replacement that is now on the way out.
I don't want the same problem again in a few more years, I thought 105 might be a suitable replacement but I think that might also be Hollowtech? Would something older from Shimano be a good replacement? I have no idea what would be a straight swap, or what might require extra parts or work, or waht might just be incompatible.

[Daveyraveygravey]

[JEA1K]

Daveyraveygravey said:

Hi all

Had my second Ultegra crank failure this morning. Well, not total failure, but it is on the way out. I bought the bike in 2015, the original had the same failure after about 3 years. I had a few arguments with Madison who didn't want to replace it because it was outside the warranty, but eventually they saw sense. It is this replacement that is now on the way out.
I don't want the same problem again in a few more years, I thought 105 might be a suitable replacement but I think that might also be Hollowtech? Would something older from Shimano be a good replacement? I have no idea what would be a straight swap, or what might require extra parts or work, or waht might just be incompatible.

This is/was a common issue with Ultegra 6800. I had 2 or 3 and they never had am issue.

I don't recall issues with 105 nor Dura Ace of the same vintage, just Ultegra.

In terms of compatibility, all Shimano chainsets use 24mm spindles, so you just need to choose 11 speed, the appropriate chairing size (saves the faff of shortening the chain) and arm length.

[Bilkob]

Unfortunately this is a potential problem with all Shimano Hollowtech cranks. The two halves of each arm are glued together. Constant load from peddling and water ingress weakens them from the inside out, and they fail
If you want to stay with your 24mm bottom bracket standard, FSA or Miche make cranksets that fit. Not really sure I’d recommend FSA, but the Miche ones are ok if a tad heavy.
Or throw all the fishing reel components in the bin and go Campag, you know it makes sense……

[Daveyraveygravey]

Bilkob said:

Unfortunately this is a potential problem with all Shimano Hollowtech cranks. The two halves of each arm are glued together. Constant load from peddling and water ingress weakens them from the inside out, and they fail
If you want to stay with your 24mm bottom bracket standard, FSA or Miche make cranksets that fit. Not really sure I’d recommend FSA, but the Miche ones are ok if a tad heavy.
Or throw all the fishing reel components in the bin and go Campag, you know it makes sense……

I like Campag, my last bike had it. But when things go wrong, it is a LOT easier to get replacements for the fishing reel stuff, than the Italian stuff, in my experience.

[Daveyraveygravey]

JEA1K said:

This is/was a common issue with Ultegra 6800. I had 2 or 3 and they never had am issue.

I don't recall issues with 105 nor Dura Ace of the same vintage, just Ultegra.

In terms of compatibility, all Shimano chainsets use 24mm spindles, so you just need to choose 11 speed, the appropriate chairing size (saves the faff of shortening the chain) and arm length.

Thanks for the info! Are the more recent equivalents any better, do you know? I just want to get the bike back on the road as quickly as possible, without throwing a load of money at it. I could get another Ultegra crank, and be ok for another 4 years, maybe, which will cost around £230 fitted. I'm wary of getting a secondhand one because it probably has less life left in it.

[JEA1K]

Daveyraveygravey said:

Thanks for the info! Are the more recent equivalents any better, do you know? I just want to get the bike back on the road as quickly as possible, without throwing a load of money at it. I could get another Ultegra crank, and be ok for another 4 years, maybe, which will cost around £230 fitted. I'm wary of getting a secondhand one because it probably has less life left in it.

Agreed. Personally I would just go with Ultegra R8000 11 speed chainset ... usually about £200 so £230 fitted seems fine if you don't have the tools.

[yellowjack]

JEA1K said:

Daveyraveygravey said:

Thanks for the info! Are the more recent equivalents any better, do you know? I just want to get the bike back on the road as quickly as possible, without throwing a load of money at it. I could get another Ultegra crank, and be ok for another 4 years, maybe, which will cost around £230 fitted. I'm wary of getting a secondhand one because it probably has less life left in it.

Agreed. Personally I would just go with Ultegra R8000 11 speed chainset ... usually about £200 so £230 fitted seems fine if you don't have the tools.

I never had an issue with my Ultegra 6800 crankset in around 16,000 miles/6 years. At least not until I needed new chainrings during the worst of the Covid lockdown supply problems. LBS were finding chainrings near impossible to source (and so was I) so they advised me to buy a a complete chainset from whatever online shop that had stock ,and they'd fit it for me. I ended up with a Shimano FC-R7000 (105) item (£150 from Wiggle - March 2021 price) that has done a trouble-free 4,000+ miles in the 20 months since it was fitted.

[calvinhobbes]

Known issue with Shimano cranks. There's a whole Instagram account dedicated to it: https://www.instagram.com/thanksshimano/

Cycling Tips did an article on what is the suspected cause and what they're doing to resolve it: https://cyclingtips.com/2022/04/whats-going-on-wit...

[Daveyraveygravey]

A little of trawling ebay over the weekend saw several potential replacements ranging from worn 105 to brand spanking new Dura-ace, and literally a fiver to 300 quid!
I went for a 105 that in all other respects is the same as my Ultegra, it started out under 40 quid but I got it for £55, so I can't really go wrong with that.

Will see if this is any more durable!