Ever had a CSU debond?

Or whatever it is that they do. Apparently my CSU is loose, how does this happen? Good thing I caught it before they failed.

From the crown? yes on a zocchi for used on the tandem – it creaked and you could feel a tiny bit of movement. the importers said it was OK to use but I replaced it anyway

this was a “cryofit” csu ie the crown is heated and the leg cooled then fitted together and once they get to the same temp they are solidly bonded

Back in ’95. Rockshox Indy XC, 2 or 3 rides old. Felt like headset had come loose. Was fitted to the Cannondale I had spent most st of my student loan on. When I took it into Alf Jones Cycles to get it checked out the ‘dale rep was in & he gave me a Headshok fork out of his van to replace it.

I’ve seen it a fair few times on Rock Shox forks, few tapered Fox forks have had the same issue. In all case the distributor sorted it out pretty quickly.

Pretty unusual then. Do you think a manufacturer would refuse the warranty on a 15 month old fork if it hadn’t been serviced?

Yes. They have several ways out of the warranty there.

but is there a valid argument that servicing could have avoided the failure?

It would be quite a long stretch to say that as the fork was not working right i put higher loads through the joint causing it to fail. For that to happen there would need to be proof that the fork was running way off optimum and used in conditions that would put it way beyond design loads.

Just tell them you have self serviced – maybe give it a quick lower leg oil change and a good clean and then warranty it. You are not being deceiving, just reducing one of the little routes they may use to get out of what should be a straight forward warranty claim.

this was a problem on 2014 RS Pikes, it happened to mine. Just horrendous creaking really. Perfectly fine to ride (which I did for quite a few months), as the steerer has a flange bit on the end meaning the crown can’t come out.

I’ve had fox forks where the steer tube has come loose and creaked seen loads of rockshox forks where this has happend too. Speak with your local bike shop who will speak to the relevant supplier and resolve the issue for you.

but is there a valid argument that servicing could have avoided the failure?

playing devil’s advocate here, but I’d say that “an competent mechanic would run his eye over the whole assembly to check structural integrity”

playing devil’s advocate here, but I’d say that “an competent mechanic would run his eye over the whole assembly to check structural integrity”

But would that still do anything to prevent the failure?

Nope. It would just potentially detect it sooner.

Sooner as in within the warranty period?

That would be significant.

The warranty on this particular fork is 2 years so I suppose the question is can a CSU failure be prevented by a 12 month service.

My Fox 32s from 2012 creak like a mofo from the CSU. Apparently it won’t fail catastrophically. Very annoying, especially since I spent from 2014 – 2016 hunting for that creak. I’ve had to apologise to press fit BBs.

Bike upside down, dribble some bearing retainer into the crown-steerer join, leave a day or two, creak disappears (probably)

I had a pair of DT swiss XM120 that creaked like a barsteward. Tried all the various suggestions of retaining compound dribbled in there etc etc. Ended up getting a new csu fitted at substantial cost. Once I knew it was the csu that was loose, I spent my whole time on the bike worrying about the fork failing. Get it changed or get a new fork..

This many replies and no one has mentioned Pace forks? (Yes I know DT came from Pace).
My BIL had a moment where the front wheel turned without him turning the bars. 1 leg had debonded from the crown and then pulled out of the crown, meaning the fork could rotate about the remaining bonded leg. EEEkkk.

Pretty unusual then. Do you think a manufacturer would refuse the warranty on a 15 month old fork if it hadn’t been serviced?

Depends who made them, but I doubt they’d refuse it. Nothing to do with servicing.

How will they know if they’ve been serviced or not? Do it today and sent off on mOonday!