# C75 fork question



## rtj67 (Jun 11, 2010)

One of the mechanics working on my bike questioned something with the Colnago C75 fork. Inside the steerer tube there is, in his words, a metal star fangled washer. He's not aware of this being installed in any forks before, especially a carbon one. His concern is that it will dig into the tube and eventually crack the steerer tube.

Any idea if this is in fact proper and the washer should be there? I had a Star carbon fork before, but don't recall... Thanks!


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## fabsroman (Jul 14, 2006)

rtj67 said:


> One of the mechanics working on my bike questioned something with the Colnago C75 fork. Inside the steerer tube there is, in his words, a metal star fangled washer. He's not aware of this being installed in any forks before, especially a carbon one. His concern is that it will dig into the tube and eventually crack the steerer tube.
> 
> Any idea if this is in fact proper and the washer should be there? I had a Star carbon fork before, but don't recall... Thanks!


What should have come with the fork is an expander plug. I believe the star washer is what comes with a Chris King headset. I have plenty of the star washers sitting around since they were not needed. I didn't use them on my Star forks or my C75 fork.

Is your frame a new frame? Did it come with the expander plug for the fork? The expander plug is actually somewhat heavy, but I wouldn't use the star expander in lieu of the expander plug. The expander plug seems to apply the force over a longer length of steerer tube versus the star expander.


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## rtj67 (Jun 11, 2010)

Thanks for the response. The frame is a C-50 that I bought used. It was built as a complete bike, not used and then parted out. It has a Chris King NoThreadSet installed, which the mechanic said needed the cups pressed.

It appears that the star washer is wedged in to the steerer tube and the mechanic doesn't believe he can get it out, without it digging in further into the tube. I have to check whether the expander plug was in the fork.


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## mtbbmet (Apr 2, 2005)

DO NOT USE THAT FORK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Whoever assembled that bike is really dumb and knows nothing about carbon forks. YOU MUST USE an expansion plug on carbon steertubes, star fangled nuts will destroy the inside of a carbon steertube making it quite unsafe.They are intended for aluminum and steel steertubes only. Ride that fork and take you life in your hands. Not kidding.


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## nago67 (May 12, 2010)

Yep that is what the mechanic building up my frame said too. Colnago double-verified it as well. Off to find a replacement fork.... Thanks for the help.


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## fabsroman (Jul 14, 2006)

mtbbmet said:


> DO NOT USE THAT FORK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
> Whoever assembled that bike is really dumb and knows nothing about carbon forks. YOU MUST USE an expansion plug on carbon steertubes, star fangled nuts will destroy the inside of a carbon steertube making it quite unsafe.They are intended for aluminum and steel steertubes only. Ride that fork and take you life in your hands. Not kidding.


Well, that is one thing we can agree on. Sucks that somebody was stupid enough to use the star expander instead of the expander plug that came with the fork.

Had two guys in MABRA land have their steerer tubes on their Madones crack off after they built up the bikes. One caused a pretty good wreck on a gravel section of a race course. The other cracked off right at the beginning of a race wherein the course had two traffic circles in it that were almost like chicaynes (sp.). It remains to be seen if it was an installation issue or a manufacturing/design issue.


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## mj3200 (Apr 18, 2008)

Ah the carbon fibre paranoia continues..................

Where's my angina spray?


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## fabsroman (Jul 14, 2006)

mj3200 said:


> Ah the carbon fibre paranoia continues..................
> 
> Where's my angina spray?


It really isn't just paranoia. If these carbon steerer tubes aren't installed correctly, including the installation of the stem, bad things can happen. Over torque the stem bolts onto the steerer tube and that can cause some serious problems.

FYI - my main rides are carbon forks with carbon steerers since they have the Star fork or the C75 fork. My racing bikes have aluminum steerer tubes on carbon forks.


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