Long 1” expander plug?

[drgonzo]

Im about to install a Columbus Minimal fork with a 1” head tube. The only expander plug I can find is the Columbus/Cinelli 1” expander (https://www.universalcycles.com/shopping/product_details.php?id=84687&gclid=EAIaIQobChMIz83nw4yH6gIVRCCtBh3FCAscEAQYASAB EgL5y_D_BwE). The problem is that it’s so short it won’t even fill the area that is clamped by the Fizik stem.

Are there any better/longer alternatives? TIA!

[Dino Suegiù]

Isn't the Cinelli/Columbus one OK since it is apparently made specifically for the Columbus Minimal 1" fork?

I have a 1 1/8" Cinelli/Columbus expander here and the serrated tube measures +/- 40mm, so = stem stack height; is the 1" model tube shorter than 40mm?

[Wakatel_Luum]

I'm on the hunt for a 1" expander too but so few choices for carbon steerer's...

[drgonzo]

Isn't the Cinelli/Columbus one OK since it is apparently made specifically for the Columbus Minimal 1" fork?

I have a 1 1/8" Cinelli/Columbus expander here and the serrated tube measures +/- 40mm, so = stem stack height; is the 1" model tube shorter than 40mm?

Yes the serrated tube part is only 29mm long so there’s no way it can extend the length of the 40mm stem clamp height (I’ve attached a pic). Maybe I’m being overly cautious but this seems strange to me. And for the life of me, I cannot find any other option for a 1” carbon steer plug.

[thirdgenbird]

FSA has one

https://www.amazon.com/dp/B002SR7HUY

[Dino Suegiù]

Yes the serrated tube part is only 29mm long so there’s no way it can extend the length of the 40mm stem clamp height (I’ve attached a pic). Maybe I’m being overly cautious but this seems strange to me. And for the life of me, I cannot find any other option for a 1” carbon steer plug.

Interesting.
I guess Columbus feel that 30mm of expander tube in a 1" steerer = 40mm of expander tube in a 1 1/8" steerer, in terms of stress distribution.

That said, I would not worry about much since the Columbus Expander 1" threadless carbon forks text reads (https://columbustubi.com/en/portfolio/columbus-expander-1-en/):
"To be used with Columbus 1" Minimal carbon fork
Product code: KGAPCAP25.4C"

And, you're using a stem shim as well, which I guess will distribute the stem clamp force a bit more evenly.

[drgonzo]

Interesting.
I guess Columbus feel that 30mm of expander tube in a 1" steerer = 40mm of expander tube in a 1 1/8" steerer, in terms of stress distribution.

That said, I would not worry about much since the Columbus Expander 1" threadless carbon forks text reads (https://columbustubi.com/en/portfolio/columbus-expander-1-en/):
"To be used with Columbus 1" Minimal carbon fork
Product code: KGAPCAP25.4C"

And, you're using a stem shim as well, which I guess will distribute the stem clamp force a bit more evenly.

I suppose you’re right, I just would have felt a little better if the expander was at least 40 or 50mm long. I wonder why they make it so short?

[ultraman6970]

Never seen a super long for 1 inch. If the steering tube is aluminum (no idea what it is tho) you can put a starnut in there.

[Dino Suegiù]

I suppose you’re right, I just would have felt a little better if the expander was at least 40 or 50mm long. I wonder why they make it so short?
Good question. I don't know. Money savings seems unlikely. It seems counter-intuitive to not make a plug length =/> stem stack height but again all I can surmise is that Columbus have calculated that 30mm of expander tube in a 1" steerer = 40mm of expander tube in a 1 1/8" steerer, in terms of stress distribution.

Anyway, Columbus fork + Columbus expander designed specifically for that fork = good to go imo.

Never seen a super long for 1 inch. If the steering tube is aluminum (no idea what it is tho) you can put a starnut in there.
It is a full carbon monocoque fork, so one should definitely not use a starnut.

[m_sasso]

These are the 1" ones I have been using for a few years, mid length second from the left. The eBay seller I usually get them from is on vacation but you should be able to get them from any Neco, Taiwan seller. Neco makes quite a few different models, you can check their corporate web site catalog online. https://www.necoparts.com/en/index/index.html

And just a side note their carbon caps are quite nice appearance wise.

https://www.ebay.com/itm/Neco-Taiwan-1-Carbon-Fiber-Bike-Headset-Top-Cap-Key-Expander-Compressor-Plug/163402419142?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649


https://images-na.ssl-images-amazon.com/images/I/61-gSdJSgEL._AC_SL1000_.jpg

[drgonzo]

These are the ones I have been using for a few years. The eBay seller I usually get them from is on vacation but you should be able to get them from any Neco seller. Neco makes quite a few different models, you can check their corporate web site catalog.

https://www.amazon.com/Neco-Headset-Expander-Expanding-Carbon/dp/B083WKRLMB


https://images-na.ssl-images-amazon.com/images/I/61-gSdJSgEL._AC_SL1000_.jpg

Thanks sasso. I had already looked into them but the only 1” plugs they make are less than 40mm long. The extra long version would be perfect but they only make those for the 1 1/8” steer tubes :(

[m_sasso]

Yep, bad news, you are correct, just checked their 2020 catalog and it looks like they stoped making the 1" X 52mm plugs. Time to find a new supplier. Have you checked with Michael, ex Sales Guy AKA Velocipede?

Or 22mm solid Al rod, cut some cylinders, drill press and epoxy, easy enough!

[drgonzo]

You should have another look, because you are incorrect.

Here is a direct link to their catalog https://www.necoparts.com/en/product/Compression-Nut/C286GL.html

I hope I’m wrong but from what I could find on their website (https://www.necoparts.com/en/product/Compression-Nut/C286G%2C+C254G.html) they make 6 versions of expander plugs - 18mm, 32mm and 52mm. Each version comes in either alloy or carbon cap. The 18mm and 32mm versions are available for either 1” (Ø20-Ø22.2) or 1 1/8” (Ø22-Ø25.4). Unfortunately they list the 52mm versions as only available for 1 1/8” (Ø22-Ø25.4).

I’d love to grab a 52mm for a 1” steer tube, please point me to where you saw it! Thanks!

[osbk67]

I'm no engineer and have used Zinn Cycles aluminium 125mm bonded inserts in the 1 1/8" carbon steerer tubes of so-equipped bikes I ride, but wouldn't an insert the same depth as the stem clamp (generally 40mm) exacerbate potential problems? Adding an internal fulcrum/stress riser at the same point on the carbon steerer as the external one? So 30mm, especially with an external shim employed, or whatever greater length puts the lower edge of the insert below the headset top race, but not 40mm being the stem clamp depth. Say at least 50mm on a steerer without spacers. Having said that I'll sit back down by the fire...

[Dave]

I avoid the expander issue entirely by filling the entire stem clamping area with jb weld epoxy, with a 6mm thread insert encapsulated in the epoxy. This avoids the problem of possibly over tightening a plug or plug slippage.

[clyde the point]

I avoid the expander issue entirely by filling the entire stem clamping area with jb weld epoxy, with a 6mm thread insert encapsulated in the epoxy. This avoids the problem of possibly over tightening a plug or plug slippage.

Where does one find that 6mm thread insert? And thanks.

[Dave]

I've used tee nuts for wood and I've also taken a 1 inch star nut and ground it down so it slips into the steerer. With a 1-1/8 steerer, very little metal is removed.

Centering a tee nut can be challenging.


https://www.amazon.com/Prime-Line-9078847-T-Nuts-4-Prong-10-Pack/dp/B07DS7HF3J/ref=sr_1_3?gclid=CjwKCAiAvriMBhAuEiwA8Cs5lWpSFq6sh ESUl5dNzQ9NP_sCSxCJnQqmMafw-1kKf70OexyO3hLqBBoCzf4QAvD_BwE&hvadid=409937781748&hvdev=t&hvlocphy=9028904&hvnetw=g&hvqmt=e&hvrand=227136806639899627&hvtargid=kwd-55496714838&hydadcr=5106_10979580&keywords=m6+tee+nut&qid=1636722723&sr=8-3

[BRad704]

Well that's certainly an idea that's never occurred to me. But I can see how it would work just fine, once you know your forever-steeter-length.


Sent from my iPhone using Tapatalk Pro

[Dave]

My current bikes have the star nut set lower, so the steerer can be cut 15mm shorter. At that point, it can only accommodate a 15mm headset top cover and a 40mm stem. I have a 30mm headset top cover and use a -17 degree stem. I could cut the steerer and use a -6, but I decided to leave the steerer longer, to improve the chances of reselling.

I know what stack height works for me, so I don't have to guess at it. I could also change to a -6 stem and raise the bars about 2cm.