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SNAFU or cluster!@#$....CF expander/compression plug

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SNAFU or cluster!@#$....CF expander/compression plug

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Old 04-16-18 | 06:20 AM
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SNAFU or cluster!@#$....CF expander/compression plug

I have a vintage full carbon fibre fork with a 1" steerer.

The carbon fibre steerer has an ID of >>2cm<< the compression plug I bought has an OD of 2.22cm and it seems to be common for compression plugs of this size.

I have thought of whittling the existing compression plug down to 1.9cm but I would have to remove material from a marginally 'strong' part.

Any kind soul out there know where I could get a compression plug which would fit ?
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Old 04-16-18 | 07:17 AM
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I might consider a solid (with threaded draw bolt hole of course) self made plug of AL and bond it into place. Andy
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Old 04-16-18 | 07:28 AM
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Originally Posted by Andrew R Stewart
I might consider a solid (with threaded draw bolt hole of course) self made plug of AL and bond it into place. Andy
It has a 2mm hole at the bottom of the fork and I managed to push an internally threaded 'plug' from an alloy bush (18mm ID) which is jammed into the steerer tube.

Yes I have thought of it but read the above =P, I was stupid young when I got it and in the process of reviving an old ride for my son.

Sorry for the blah and thank you for the advice. Great idea by the way.
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Old 04-16-18 | 08:49 AM
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Originally Posted by L0TT0
I have thought of whittling the existing compression plug down to 1.9cm but I would have to remove material from a marginally 'strong' part.
The plug really doesn't need to be super strong. Once you've set your bearing preload and tightened down the stem bolts it's job is done.
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Old 04-16-18 | 10:09 AM
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[MENTION=481085]L0TT0[/MENTION] is likely using a plug designed specifically for 1 1/8" steerers.

Plugs for 1" steerer are available. A good shop will have a selection of plugs to try.
Expansion plugs cannot be "Whittled" down. They have a knurled surface to grip the inside diameter of the steerer and any attempt to file or machine it will ruin it.


-Tim-
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Old 04-16-18 | 10:17 AM
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Expansion plugs are specifically made for steel or carbon steerers in both 1" and 1-1/8". You need to find a 1" carbon steerer plug.
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Old 04-16-18 | 10:53 AM
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Originally Posted by TimothyH
[MENTION=481085]L0TT0[/MENTION] is likely using a plug designed specifically for 1 1/8" steerers.

Plugs for 1" steerer are available. A good shop will have a selection of plugs to try.


Expansion plugs cannot be "Whittled" down. They have a knurled surface to grip the inside diameter of the steerer and any attempt to file or machine it will ruin it.


-Tim-
Yes I was looking at the internal bits of the plug and not the knurled sections, thank you again. 😊

I have bought one sad thing is that most of the of these have an diameter of 2.2 at the minimum.
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Old 04-16-18 | 11:47 AM
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Profile Design compression plugs on eBay (or Treefort, Niagara, etc.) go down to 19.6mm. Can't vouch for quality, but have used one of their stems in the past. Or maybe an older Cinelli 1".

John

Edit added: I would think a 22mm minimum would be for a 1-1/8" steerer considering a 1" steerer has a 25.4mm OD. 1.7mm wall thickness seems a bit thin for a carbon steering tube.

Last edited by 70sSanO; 04-16-18 at 01:35 PM.
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Old 04-16-18 | 01:48 PM
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Originally Posted by 70sSanO
Profile Design compression plugs on eBay (or Treefort, Niagara, etc.) go down to 19.6mm. Can't vouch for quality, but have used one of their stems in the past. Or maybe an older Cinelli 1".

John

Edit added: I would think a 22mm minimum would be for a 1-1/8" steerer considering a 1" steerer has a 25.4mm OD. 1.7mm wall thickness seems a bit thin for a carbon steering tube.
I just found the same exact item awhile back. Thank you =)
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Old 04-16-18 | 01:59 PM
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Originally Posted by HillRider
Expansion plugs are specifically made for steel or carbon steerers in both 1" and 1-1/8". You need to find a 1" carbon steerer plug.
That is what I am trying to do =)
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Old 04-16-18 | 03:07 PM
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Cinelli 1" expander plug Universal Cycles



The top cap even has the classic Cinelli dove icon which is a bit of a collector item. The top cap may need to be replaced with a 1.125 cap however, depending on the OP's application
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Old 04-16-18 | 05:28 PM
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Originally Posted by TimothyH
Cinelli 1" expander plug Universal Cycles



The top cap even has the classic Cinelli dove icon which is a bit of a collector item. The top cap may need to be replaced with a 1.125 cap however, depending on the OP's application
+1 This is the right type.
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Old 04-16-18 | 08:32 PM
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Originally Posted by Crankycrank
The plug really doesn't need to be super strong. Once you've set your bearing preload and tightened down the stem bolts it's job is done.

The reason to have a pressure plug isn't for drawing up bearing preload, that can be done other ways. It's to keep the carbon steerer from collapsing or cracking from the pressure (hence the name) of the stem clamping. Not a problem for steel or AL steerers. Andy (who remind all of one more reason to be careful about carbon in certain applications)
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Old 04-16-18 | 10:15 PM
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This video explains the purpose of an expansion plug, why they are used and what to look fo when selecting one.

The video is worth the ten minutes for anyone who has a carbon steerer.



-Tim-

Last edited by TimothyH; 04-16-18 at 10:44 PM.
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Old 04-17-18 | 09:49 PM
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You guys have been great. thank you =)

I have already moved on to phase two of my little project.....assembly.
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