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Giant Wedge Seatpost Clamp Issues

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Lava

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Discussion starter · #1 ·
I've had my first frame replaced after the seat-tube on my first Giant XTC 2017 (2) Medium sized cracked.

It's started with loud creaking noises at the wedges. I took it into the shop, and Giant replaced the frame.

I now have a new frame, and the wedge is still doing this same loud cracking/popping sound when I go over bumps. I've taken it back to the shop and they replaced the wedges. And still it doesn't go away.

Here's how I tried to manage it.

1) First, never un-screw the bolt, and I try and set and forget it.
2) I apply grease over all the wedges and the bolt.
3) Then I apply Giant's (prepacked carbon fiber grip) to the inside of the seat tube, and over the seatpost.
4) I make sure that there is no grease touching the frame, and just have carbon paste on the frame and seat tube.
5) Prior to installing/and adding fresh materials, I made sure everything is washed thoroughly (no sand/or old grease.

Now As I tighten up the bolt with the number 4 hex key, I hear the wedges creaking/cracking, and get's less as it meets the 8NM max threshold. But riding it at 8NM makes so much noise, I can even get the wedges to creak and crack when just moving the saddle by hand. Upping the torque makes the creaking less often, but it's still there - I don't know what to do, and I think the shop is getting tired of this same issue over and over.

I think this happens because of the wedges moving over each other, as this is metal on metal. I weight 83Kg and try and get off the saddle over almost everything now.
If I road ride it's great, then I don't hear anything, unless I shift a little in the saddle when my ass get's numb, then I expect a popping sound again.

Has anyone got a solution for this? The bike shop guy said that this is common with Cannondale also. He said to use Carbon paste with everything, but this also doesn't work. :(
 

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#2 ·
I have the same problem. They also changed the frame, but with the new one the problem has not been solved. I have tried everything, but the crack sound does not disappear. I'm sure it's a Giant design problem, but maybe someone has managed to fix it and can help us.
Please help!!!
 
#3 ·
No idea why Giant decided to use this design. Clint Gibbs mentioned it on his vid review of the bike as well (start about 1:40) so you're not alone. I don't know if there's a guaranteed solution. Too bad because it's an otherwise awesome bike.

 
#5 ·
Thanks for your comments.
I hope it's not a design flaw, and that the problem is that we're doing something wrong. I have spoken with several Giant technical assistants, and they all tell me that in theory there is nothing special to do to make it work properly.
I will continue researching and testing different configurations.
 
#6 ·
so that clamp looks like my Giant Defy, the top of the frame is where to access the bolt ?

My 2015 XTC has a bolt underneath, and one wedge, not multiple pieces.

when the bike was new it made a few loud cracks, and when I got back and inspected it, it turned out the cracks was carbon fiber flashing from around the wedge gap and seat tube area, left over from manufacturing. Once I cleared it out ...it cracked (I mean made a crack sound, nothing really broke) one more time when I landed wrong on the saddle. again, took apart, cleaned it, found a tiny piece of carbon flashing. cleaned it, relaid down some tacx carbon paste, tightened up to (this one is speced at 10nm) and no issues since.

so.......maybe it is thin over-moulded carbon flash that need to be chunked out
of the area ? I have a borescope and looked in mine and all is well after the initial 'breaking' in....
 
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#7 ·
LarryFahn said:
Who ever thought such a simple device such as a seatpost clamp wasn't "technologically advanced" enough for a bicycle and was a real issue? Ttyl, Fahn
Click to expand...
yeah I agree. the XTC is a fine bike, but it doesn't need a space age seat clamp. just make it regular, I still would have bought the bike itself. all that does is make it pretty on stage at Interbike.
 
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Discussion starter · #9 ·
The real issue is that I cannot work out where the cracking is originating from. But here's my findings - When I pull the seatpost back, there is a slight clicking sound, and when I push it forward from there, a loud crack sound.

Now this happens almost over every single little bump in the road. when riding, since I'm sitting with my full 83KG's of weight and moving the seatpost around. Also the seatpost is one of those thin ones, so there is a lot of flex and bending - especially right down below where those forces collect on the wedges.

I'm guessing it's the wedges being moved away and to the frame that's causing that cracking sounds. It's almost as if the seatpost area is not tight enough, and there is too much play there.

I've asked the bike shop if I should not maybe inset a lining of inner seat-tube down there and see if this makes things more snug, to which they said it's worth a try.

But I'm not going open the wedges again, each time I've taken the post apart the noise have gotten worse and worse. I'm almost done paying off this piece of ****, then I'm getting a proper XC brand and bike.
 
#10 ·
Lava said:
The real issue is that I cannot work out where the cracking is originating from. But here's my findings - When I pull the seatpost back, there is a slight clicking sound, and when I push it forward from there, a loud crack sound.

Now this happens almost over every single little bump in the road. when riding, since I'm sitting with my full 83KG's of weight and moving the seatpost around. Also the seatpost is one of those thin ones, so there is a lot of flex and bending - especially right down below where those forces collect on the wedges.

I'm guessing it's the wedges being moved away and to the frame that's causing that cracking sounds. It's almost as if the seatpost area is not tight enough, and there is too much play there.

I've asked the bike shop if I should not maybe inset a lining of inner seat-tube down there and see if this makes things more snug, to which they said it's worth a try.

But I'm not going open the wedges again, each time I've taken the post apart the noise have gotten worse and worse. I'm almost done paying off this piece of ****, then I'm getting a proper XC brand and bike.
Click to expand...
well, ASIDE from the noise (and if my bike made a noise like that I would demand full refund)

the XTC is one of the ultimate hardtails ever produced

but that seat clamp design is BULL. I almost tossed mine but I did figure out
what the noise was on my 2015 XTC and it is fixed and ...best hardtail ever...

dammit Giant !!!!! you make great stuff but didn't work out your fancy clamp in QA didja ?

this picture is of the headtube area on a different bike, but I am using
it as an example of carbon flashing that was in my seatpost area. this is the thing
to reach in and break off with your fingertips if there is any of this inside the frame. it caused maddening creaks and crack sounds on my XTC until it all
just broke off and ...now silent
Image
 
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Discussion starter · #11 ·
Deep down in my seatube the only weird thing I could see is a small chip - I've taken it to the LBS who then took the frame to GIANT, who said - that it's just a roughly done job and is nothing to worry about. I cannot claim that this is the cause for the cracking.

My thinking is I cannot smooth anything out in there, it's too deep - if it does however fail like the previous frame did - I will take it back to GIANT for a refund. Will will not want the same frame again, I'd rather downgrade to an alloy Anthem but from prior 2017 when this "tech" was introduced. But thanks for that perspective of the "flashing." That was good insight!
 

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#12 ·
I tell you things that have worked for me temporarily. Carbon paste in the contact zone of the seatpost with the frame. In the area of ​​contact between the seat post and part I do not put anything. I clean very well with degreased Finish Line the wedges and the screw.
In this way I have managed to make it two months without making the noise. After that time I had to do the same thing again.
 
#13 ·
The industry wants you to believe that "carbon is better". Remember though, we all rode aluminum for 20+ years. It's not a "downgrade" by any means. It's just a way of changing a stale market and pushing more changes in our faces. Ttyl, Fahn
 
#14 ·
Today I tried something else:
Carbon paste in the contact zone of the seatpost with the frame. In the area of ​​contact between the seat post and wedges I do not put anything. I clean very well with degreased Finish Line Speed Clean the wedges and the screw. With the degreaser, also clean the contact area between the frame and the wedges. Then I apply Loctite 222 fixer on the screw thread. What I intend with all this, is that the portions do not move. Today I went with the bike, and it seems that it worked well. I'll tell you if it's a solution and hold on.
Sorry for my English, I'm Spanish and it's a bit difficult for me to write in English. I'm trying to improve!
 
#16 ·
My bike is a Giant XTC 1.5 2017, but when I changed the framethey put me on XTC 0 2018. I have put many improvements: carbon seatpost and seat, monoplate, ultralight wheels... I managed to leave it with 9.8 kg of weight. It is the L size
 
#18 ·
Hello Lava! Have you tried the solution I gave you? It's working for me, I'm very happy. The key is that the screw and the wedges do not move. In addition to the instructions I gave you, I also put in some grease (no carbon paste!) In the center wedge. This is to avoid small creaks, not the main noise. It is very important that the wedges and the contact area of the frame with the wedges, haven't grease or carbon paste, so it is best that you put the seatpost and the portions at the same time.
 
Discussion starter · #19 ·
Brilliant, thank you. Yes I have seen your solution - and will be trying this method next time I absolutely need to take out the seat-post again to clean it. It's currently turning winter and my rides end up with lots of mud and sand in everything.

I'm currently hearing only a creak/crack when going standing up after being on the seat, and whilst climbing rough uphills. It's quiet when on the flat roads.

Thank you again for sharing your experiments - happy riding!
 
#20 ·
Good day everyone.

I just inspected my Giant's integrated seatpost clamp and found out there are some chipping above the wedge part. I wasn't able to notice it before as I set and forget that part until recently when I inspected the bike and this is what I found:

Is this normal on Giant bikes or is there anything I need to worry about like breaking or something like? I'm not sure if its just paint chip or it had already penetrated through...

Thank you very much in advance
 
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