SNAFU or cluster!@#$....CF expander/compression plug
#1
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SNAFU or cluster!@#$....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 ?
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 ?
#2
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From: Rochester, NY
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
I might consider a solid (with threaded draw bolt hole of course) self made plug of AL and bond it into place. Andy
#3
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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.
#4
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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.
#5
- Soli Deo Gloria -
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From: Northwest Georgia
Bikes: 2018 Rodriguez Custom Fixed Gear, 2017 Niner RLT 9 RDO, 2015 Bianchi Pista, 2002 Fuji Robaix
[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-
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-
#6
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Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
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.
#7
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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-
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-
I have bought one sad thing is that most of the of these have an diameter of 2.2 at the minimum.
#8
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Bikes: 1986 Cannondale SR400 (Flat bar commuter), 1988 Cannondale Criterium XTR, 1992 Serotta T-Max, 1995 Trek 970
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.
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.
#9
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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.
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.
#11
- Soli Deo Gloria -
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From: Northwest Georgia
Bikes: 2018 Rodriguez Custom Fixed Gear, 2017 Niner RLT 9 RDO, 2015 Bianchi Pista, 2002 Fuji Robaix
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

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
#12
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From: Pittsburgh, PA
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
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

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
#13
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From: Rochester, NY
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
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)
#14
- Soli Deo Gloria -
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From: Northwest Georgia
Bikes: 2018 Rodriguez Custom Fixed Gear, 2017 Niner RLT 9 RDO, 2015 Bianchi Pista, 2002 Fuji Robaix
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-
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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