Cranks Brothers stems - one good, one cheese?

[2manyoranges]

I bought an Iodine 3 shorty stem (new) and put that on the Cannondale, and that was nice. Single bolt pinch fitting. Torx, but you can’t have everything. Then I needed another 50mm shorty for the Grom and bought an Iodine 1 stem (new) and started fitting that. I usually rely on 30 years of spannering to get the right torque but I have recently decided to follow torque spec on carbon kit, so I thought i’d Be ‘good’ and use it on alloy too. The Iodine 1 has two trad pinch bolts, and states 5mn, so I set the wrench at 4 ish and did the first tighten. Bolt stripped the thread. Soft as cheese. Just for fun I tightened the secind bolt. Same thing. Torque wrench is reasonable spec, so it seems to be the stem not the wrench. Anyone else had this with Iodine stems?

 

[benjabbi]

They did an Iodine with a carbon faceplate, the first one cracked well before the 5NM torque spec, I chalked it up as a faulty one and received another under warranty, that did exactly the same. The torque wrench was calibrated between the two, just in case. Freshly greased bolts etc.
Sounds like the steerer clamps are crap as well! Never got that far on mine, just bought a Thomson X4 instead!
I've been bitten once too often by Crank Bros, there newer stuff could be the best available but the damage is done, they'll never get their hands on my money again.

 

[2manyoranges]

Re:

Here the little tinker.....

 

[2manyoranges]

Re:

Benjabbi - thanks...this somewhat reinforces my impression of their quality control. Many things can fail on a bike and be inconvenient but not life threatening. A stem is not one of them. Stem failures are not funny.

Thanks for the response...very helpful.

 

[benjabbi]

Yeah that's the one. I think mine was a 3 looked the same but with a carbon faceplate. Is there enough thread left to try longer bolts? I suspect not! I'm not sure I'd trust it anyway!

 

[2manyoranges]

Re:

Thanks ... yep that’s what I am considering - in the background of the photo you will see a longer bolt I am thinking about fettling in. But everything is shaped and recessed, so I will have to make a very careful choice of nut/fixing.

This made me look up the effects of putting on lube or antisieze on a bolt when using a torque wrench. There’s a LOT of controversy about it....

http://benmlee.com/4runner/threads/threads.htm

Do you know if this has been discussed on RetroBike before? If not I may start a thread.....

 

[benjabbi]

I've always used grease on bolts, and had heard that anti-seize could cause false readings but, having read your link- 71% over torque! That's a bloody big difference, I wonder if grease has a similar, if not quite as bad effect? Might have to start using oil!
I don't recall there ever being a thread on the subject.

 

[2manyoranges]

Re:

Thanks - I think I need to dig into this a bit. I have always used a torque wrench on car wheels, suspension, etc but always followed exactly the guidance re lubed or non-lubed in those contexts - eg VAG wheel bolts s definitely non-lubed. I’ll dig a bit more and then post. It might save a few components and increase safety a little...

Many thanks

 

[mattr]

Most torque specs default to light oil on the threads.
So unless it says otherwise, that's what I do.

Alternatively, just tighten until it stops whatever it's clamping moving.
Silly question, but you did snug up the bolts and get everything in place before tightening to torque?

 

[2manyoranges]

Re:

Mattr - yes, I did the ‘do it up with fingers, then do it up gently with a tool, then do the penultimate bit with a torque wrench on a lower setting, then do it up for the final bit on the right setting..’. I used a very light film of grease and maybe that was the problem. But it stripped before I got to the ‘final bit’ part. I still think it could be a cheese problem, since there have been other tales in the past of CB QA problems.