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PostPosted: Tue Jul 23, 2013 5:33 pm 
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until the point you said the numbers matched, I was going to suggest looks like someone has bodged a steerer extension of some type to get forks to fit which would explain why given lack of crash damage, as others advise, needs to be checked by frame builder........


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PostPosted: Tue Jul 23, 2013 5:35 pm 
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Rampage wrote:
Looks to me like the origional steerer has been cut off and then a length of something has been tapered so that it fits inside the old steerer.
Do you have means to accurately measure the outside diameter of the new steerer tube section?


Steerer has the same frame number stamped on it as the frame so it's the original steerer and they are the original forks - Giant composite in purple which came with the lime green frames. It isn't a frankenstein job of two separate pieces, more a complete hash of a repair.


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PostPosted: Wed Jul 24, 2013 12:19 pm 
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Midlife wrote:
Looks like it has been repaired / modified and held with two-mix epoxy putty (fake metal). There are not a lot of things that worry me about bits on a bike breaking............apart from the forks :(

It would play on my mind that any minute now my face would be plunging towards the tarmac.

I'd either replace or send to a frame builder for a *propper* repair.

Shaun

+1


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PostPosted: Wed Jul 24, 2013 2:12 pm 
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Location: A wretched hive of scum and villainy...
It looks to me like an original Giant fork, specially if all the serial numbers match.
Giant were pioneers in bonded and composite bikes.

The upper part of the steerer has been swaged down to be a bonded plug fit into a cast crown, not a cheap bodge process. It does give a 'neck' to the steerer, which is not good structural design. Maybe this is a 1" - 1 1/8" transition period fork?

Most modern carbon forks are constructed this way, with an aluminium crown and separate bonded steerers (in carbon or aluminium) and blades. These days the steerers remain 28.6 straight into the bonded joint. Only the very high end stuff is truly monocoque.

The smoother metal finish on the lower section is from the reaming of the headset crown seat after bonding, hence the smoothed off section of white epoxy.
I can't say if it's OK to ride, that's up to you. It would be worth trying to assess the length of the bonded joint and the wall thickness of the steerer around the joint.

All the best,


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PostPosted: Wed Jul 24, 2013 8:28 pm 
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You make a very good case Dan, so thanks for an alternate perspective on this one. This has been bugging me all day, as I simply cant think of a reason why someone would repair in this manner - the bottom section has been cut very straight and the swaged section, despite appearances, has been done very neatly in that it's constant in it's 'machining'. The overall job looks rough around the bonding and the fact that a steerer section like this is the last thing you'd expect to see - so your mind is made up already that it's been broken and then fixed.

Halfway down this page http://my.opera.com/badmadcyclist/blog/?startidx=2620 is a cutaway picture of a a carbon fork and there's a lot to be said of the similarity to how mine appears to be constructed - at least there's some idea that the steerer on a carbon tube isn't perhaps built as we all might expect?

So - does this mean i'm any more confident in riding on these forks?....erm, no not really. I'm going to contact Giant and see if there's anyone there who can I ask some questions of...basically if this is how it came out the factory i'm happy to ride it (I think), if it's any sort of repair then it's to the skip.

If I hear anything back i'll post it up here so that it's out there for anyone else who finds such a gruesome discovery :shock:


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PostPosted: Thu Jul 25, 2013 6:35 am 
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Id never ride anything with a repair like that. period. On downhill runs it would be playing on my mind all the time.


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PostPosted: Fri Aug 30, 2013 9:56 am 
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Well Gentlemen,

Given I was looking at financial recompense from the seller, I thought I'd fire off an email to Giant UK with the hope of getting confirmation that these forks had been bodged. How wrong could I be (in using the word 'I' I off course mean you lot as well :) ) Turns out that this was the production method employed at the time...

"From factory - This is how they are bonded and then they are cleaned for any excess over spill. So no need to worry about this being repaired"

That's the extract from Giant UK that I received this morning. This however, hasn't at this time built up my confidence to such an extent that I'd be willing to brake hard so I guess it's a case of getting some miles in and building the confidence up. Or I could just swap the forks but I don't fancy changing headset, stem etc as this was a parts bin build done for less than £200.


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PostPosted: Fri Aug 30, 2013 10:34 am 
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Joined: Tue Oct 09, 2007 1:55 pm
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There are really some things best not known!


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PostPosted: Fri Aug 30, 2013 11:14 am 
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hamster wrote:
There are really some things best not known!


Oh so true - I wish I hadn't taken the forks out of the frame!


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PostPosted: Fri Aug 30, 2013 11:25 am 
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Joined: Wed Apr 24, 2013 8:09 pm
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Location: cheshire
i carnt fig out the point in doing this, is it a bigger bearing at the bottom? also the bottom looks steel top looks alloy to me maby its to save weight, seems wrong, but if thats how they are then thats it lol


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