Shimano 105 warranty query - chainset issue

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geopat

Über Member
Location
Edinburgh
As my previous threads indicated I updated my groupset to Shimano 105 in April this year.

A couple of weeks ago going up a hill the pedals wouldn’t turn and I came to a sudden stop. Turns out a couple of inner chain ring bolts had come loose and fell out leaving the inner chainring separated from the outer. Due to the force I also bent the inner chainring.

Now I have never had these bolts come loose never mind fall out before and it’s an area I would never check - lesson learned. But given the fact the groupset was only 8 months old with less than 1k miles in it should It have failed so quickly?

My LBS returned the chain set to Madison and they rejected my claim as the issue was caused by loose bolts. I can understand if the component is over 1 year old in which case the bike would have been due a service check but not at 8 months.

I realise I am probably expecting too much getting a replacement free and the fault is mine for not checking the bike but just enquiringly as to whether others would accept Madison’s decision. Thanks.
 

SpokeyDokey

67, & my GP says I will officially be old at 70!
Moderator
I would accept it but on the other hand I wouldn't have complained in the first place.

Part of any routine checking program for a bike owner is checking all bolts periodically. Chainring bolts are torqued pretty tight and I've only ever had the occasional one get even slightly loose but it is a high stress area and is still worth checking.

Hope the rest of your bike didn't suffer any damage.
 

Ajax Bay

Guru
Location
East Devon
These chain ring bolts would normally have lock thread on them. When you replace the inner chain ring, make sure you use it. Must admit you're 'unlucky' you didn't 'feel' the looseness as first one and then the second bolt came loose/fell out. Like @SpokeyDokey I would accept it.
 
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I like Skol

A Minging Manc...
Seems like it might be a design flaw. I checked mine after a tale of woe similar to yours from @Kestevan and sure enough I found that the bolts, while not loose, were certainly not tight. Something that I do check occasionally now even though I have never needed to on other bikes with different chainsets fitted.
The 105 chainrings might be a clever design with hidden bolts but maybe it isnt as structurally robust as the old fashioned chainring through bolts?
 

Kestevan

Last of the Summer Winos
Location
Holmfirth.
Yep. Ended up having to replace the whole Crankset on mine after similar.

Issue is made worse because the loose bolts damage the thread, but unlike the old separate through bolts, the thread is machined directly into the spider. Knackered thread = new Crankset.
 

400bhp

Guru
I had a new outer chainring put on my ultegra crank in March. It had started to click and a couple of months back I took it into my LBS who spotted the bolts had come loose.

Now I'm sure he said this was a common problem with 105 but he'd never seen it on Ultegra (this was prior to me telling him I had the outer chainring replaced on my ultegra).
 

400bhp

Guru
I realise I am probably expecting too much getting a replacement free and the fault is mine for not checking the bike but just enquiringly as to whether others would accept Madison’s decision. Thanks.

Not your fault at all if the bike is 8 months old.
 
Location
Spain
Who fitted the new groupset?
 

jessand

Veteran
I don't see the relevance of 8 months? If you've done 1000 miles that's something like 300,000 revolutions - I can see that chainset bolts may work loose over that period. My experience is that I've never had any come loose although I do remove and refit them annually, that's at 3-4000 miles. It would appear that the bolts weren't torqued properly on initial assembly. Maybe that particular is badly designed as others have said.
 
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