Proper Use of Expander/Compression Plugs

[TobinHatesYou]

Hi guys... I’m bringing the issue back again... what is better to use the short or long compression plugs... I would say straight away that a longer one would do a better distribution of loads around the fork and would increase the friction (although penalising the weight). Another question is, would you use carbon compound in order to again increase friction... additionally I’m asking this because of a “tantan (Chinese)” project and I’m concerned about the torques everywhere!!!

Longer is better, with the caveat that there are some less that optimal long designs that don't make as much contact as fully sleeved options. You generally don't need fiber grip as the expanders have textured or knurled surfaces. Make sure you don't overtorque the expander plug because carbon cylinders can't take as much load in expansion as they can in compression.

[andriyi1]

Hi guys... I’m bringing the issue back again... what is better to use the short or long compression plugs... I would say straight away that a longer one would do a better distribution of loads around the fork and would increase the friction (although penalising the weight). Another question is, would you use carbon compound in order to again increase friction... additionally I’m asking this because of a “tantan (Chinese)” project and I’m concerned about the torques everywhere!!!

Longer is better, with the caveat that there are some less that optimal long designs that don't make as much contact as fully sleeved options. You generally don't need fiber grip as the expanders have textured or knurled surfaces. Make sure you don't overtorque the expander plug because carbon cylinders can't take as much load in expansion as they can in compression.

Thanks for the reply mate... would you recommend any in particular??


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[Lewn777]

Great post. We discussed this on another thread, engineers mostly suggest supporting the bottom bolt with an expander long enough to reach that far, which means use of spacers above the stem should be avoided. Also that some manufacturers that supply very short plugs believe that their steerers are tough enough to withstand those forces, so it is obviously not advisable to switch out a long plug that might of come with your bike for a shorter one.

[OlieSimpson]

Reviving a VERY old thread here!

I'm looking to replace my stock steertube expander and am wondering if anyone has any feedback on the 70mm Deda expander or the Colnango Expander which I think is over 100mm in length?

Deda: https://www.chainreactioncycles.com/ded ... prod171842

Colnago: https://www.chainreactioncycles.com/col ... prod196617

[gkski]

Both should provide great steerer tube support. Also look at the Origin 8 compression plug.

[musiclover]

Reviving a VERY old thread here!

I'm looking to replace my stock steertube expander and am wondering if anyone has any feedback on the 70mm Deda expander or the Colnango Expander which I think is over 100mm in length?

Deda: https://www.chainreactioncycles.com/ded ... prod171842

Colnago: https://www.chainreactioncycles.com/col ... prod196617

Get the Deda one, Colnago is too slipery. May slide right out.

[c60rider]

Reviving a VERY old thread here!

I'm looking to replace my stock steertube expander and am wondering if anyone has any feedback on the 70mm Deda expander or the Colnango Expander which I think is over 100mm in length?

Deda: https://www.chainreactioncycles.com/ded ... prod171842

Colnago: https://www.chainreactioncycles.com/col ... prod196617

Get the Deda one, Colnago is too slipery. May slide right out.

Got Colnago's fitted to all my frames after I first had one with my C60. I won't fit anything else. They've been torqued to the specified amount and never moved once.

[mag]

The Colnago one is fine, no issues with slipping here.
The Deda one is fine as well, but it has slightly larger diameter. Make sure it would fit into your steerer tube (>= 23.5 mm ID) before purchasing it.

[musiclover]

Got Colnago's fitted to all my frames after I first had one with my C60. I won't fit anything else. They've been torqued to the specified amount and never moved once.

Depends on how smooth the internal surface of the fork is I guess. It slipped multiple times in my Boardman until I got PRO one which looks like Deda. Out of the top of my head I think the recommended torque was 9 Nm which I adhered to.
You lose nothing getting a rougher design with more friction.

[wooger]

Great post. We discussed this on another thread, engineers mostly suggest supporting the bottom bolt with an expander long enough to reach that far, which means use of spacers above the stem should be avoided.

Not sure that spacers are relevant really - does this not just mean that the expander plug needs to be at the same point the stem is attached? So provided you have or get a long enough bolt to reach and position the expander in the right place, why would spacers above the stem be an issue at all?

[DaveS]

If a short spacer is placed at the bottom of the stem, it leaves the top of the steerer unsupported. My Cinelli expanding plugs have a ledge at the top, so the have to sit on top of the steering tube and then a spacer is needed on top of the stem.

I avoid all of this problem by gluing a thread insert low enough that it supports the bottom of the stem and the rest is filled with solid epoxy, so the top of the steering tube is also supported. Most of my steerers are slammed, but my current ones have 15mm that could be cut off. I most often use a star nut, ground to a diameter just small enough to barely slide into the steerer. Once epoxies in place, I have good support and no chance of slippage.

[c60rider]

Got Colnago's fitted to all my frames after I first had one with my C60. I won't fit anything else. They've been torqued to the specified amount and never moved once.

Depends on how smooth the internal surface of the fork is I guess. It slipped multiple times in my Boardman until I got PRO one which looks like Deda. Out of the top of my head I think the recommended torque was 9 Nm which I adhered to.
You lose nothing getting a rougher design with more friction.

Bit of carbon paste certainly can help here. I use it as a routine when I'm tightening things against carbon so maybe that makes the difference.

[musiclover]

Bit of carbon paste certainly can help here. I use it as a routine when I'm tightening things against carbon so maybe that makes the difference.

Did not change anything for me.

[OlieSimpson]

The Colnago one is fine, no issues with slipping here.
The Deda one is fine as well, but it has slightly larger diameter. Make sure it would fit into your steerer tube (>= 23.5 mm ID) before purchasing it.

Good catch, the ID of my steerer tube is only 21.5mm so the Deda won't work unfortunately.

So...can anyone recomend something similar to the Deda 70mm compression plug that will with a 21.5mm ID steerer tube?

[musiclover]

The Colnago one is fine, no issues with slipping here.
The Deda one is fine as well, but it has slightly larger diameter. Make sure it would fit into your steerer tube (>= 23.5 mm ID) before purchasing it.

Good catch, the ID of my steerer tube is only 21.5mm so the Deda won't work unfortunately.

So...can anyone recomend something similar to the Deda 70mm compression plug that will with a 21.5mm ID steerer tube?

That's what I use. https://www.pro-bikegear.com/global/acc ... ander-long ps oh sorry it seems that it says "Minimum inner diameter: 23mm" in the description there.

You will need to search for something with your non-standard steering tube.