Deda 70mm expander - no torque values?

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MaxPower
Posts: 407
Joined: Fri Sep 20, 2019 9:30 pm

by MaxPower

Hey all Deda expander plug users

What Torque do you use for a deda expander? i would think it is the same for the 45 and 70mm version.

i have the 70mm (for a bike were expander slipping with the original FSA was a issue), and was suprised to find no markings about torque what so ever.

only thing i could find was a handlebar/stem manual from deda saying 3 Nm - which to me sound like very little?!?


Since the expanders seems to be popular for carbon steerers - let´s hear what the different owners do.

Thanks for the input.

Br

c60rider
Posts: 872
Joined: Mon Feb 27, 2017 11:12 pm

by c60rider

I have the super long Colnago expander in all my compatible frames, I forget how long it is but I've not seen one bigger, that has max 8Nm max stamped on it. I put carbon paste around it then tighten up typically to about 7.5Nm and they've never moved on any frame.

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g00se
Posts: 94
Joined: Fri Feb 21, 2014 11:22 pm

by g00se

I wouldn't think it would need too much. It's not there to push out on the steerer - it's there to block compression from the stem (and help with pre-loading the headset bearings before the stem is tightened). /

The Cervelo/3T way is to epoxy a metal cylender into the steer - which contains an old-school star-nut. That's just a friction fit and achives the same effect.

PoorCyclist
Posts: 783
Joined: Wed Dec 07, 2011 1:26 am
Location: California's country side

by PoorCyclist

When you first drop it in you can still spin it but then it will grab, you can probably add 1/8 a turn and stop. Or pull with one finger until a L shape hex key starts to flex a little. But that doesn't work so well if it is a 8mm hex key. (usually I see 6mm) So just snug and check it.

There is no need to pull until your muscles shakes or such, you might possibly make the steerer bellow out. You can always come back and add some more torque if needed.

3Pio
Posts: 1581
Joined: Wed Mar 09, 2016 7:13 pm

by 3Pio

MaxPower wrote:
Tue Apr 05, 2022 1:32 pm
Hey all Deda expander plug users

What Torque do you use for a deda expander? i would think it is the same for the 45 and 70mm version.

i have the 70mm (for a bike were expander slipping with the original FSA was a issue), and was suprised to find no markings about torque what so ever.

only thing i could find was a handlebar/stem manual from deda saying 3 Nm - which to me sound like very little?!?


Since the expanders seems to be popular for carbon steerers - let´s hear what the different owners do.

Thanks for the input.

Br

Interested about the same.. And also just recently i realized that in manual they stated 3nm which to me look low torque for the expander.....

Just for comparation:

Specialized Fork Expander 45mm - They have 9nm max torque

Colnago Fork Expander 8nm on the expander, but 7 nm in the manual of C60 Manual (I was using here 8nm, but in last checking i went 1nm down 7nm as i stated in the manual of the bike.. When i checked internal surface there was no any damage or problems)

Enve for their fork on install video they use 8nm for expander they use (7nm in faq):

https://support.enve.com/hc/en-us/artic ... structions


When i google it a little bit what harm can be done if u overtorque expander to expand the fork from inside, i realized in extreme casing there is some bulging of the fork stereer before crack happening (i guess it depend from fork stereer material but did not find any crack from my search, and u can check that with spacers sliding on the stereer and realize if there is some change in the diameter after expanding the fork expander). But i dont remember that i find anyone to crack the fork stereer with over expanding...

In my case i was testing that Deda 70mm expander on cutout part of the fork stereer and went to about 7-8nm and did not not noticed any bulging or some issue on the fork stereer part (again i was experimentng on cutout stereer part).

And personally i think that more harm can be done from slippery fork expander (imagine since it's metal all the deep scratching will be done on the surface if there is some slippage of fork expander inside the fork and potential damage on carbon from that)...

Or moments when there is setting the headset just using torque values in some services (with slipped fork expander) and not nice rocking test and damage that can be done from lousy headset (i also have idea that more damage is done with lousy headset on fork stereer, frame etc than overtighten (in that case u'll feel and in worst case bearings will be damaged first, and u'll get the feeling when wheel is centering and to back off...) Im not sure if possible from overtighten headset to damage the frame/fork bearing contact part, i guess its possible but only if u really really over tighten the things which is definitely noticable and less likely then lousy expander, headset...

Also Deda expander is 68mm long, which mean that torque is spreading on wider area so i guess 9nm on short expander (Specialized for example 45mm long) will do more stress on the fork then with longer expander and same torque value (but i guess it depend from the material of bolt mechanism etc what will be real end torque..)

But if get some avg values for expander using same 6mm bolt and similar mechanism i think that 3nm will be too loose fit, but the end of the depend from the fork and other things...

For the end.. Im really interested in what value u settle after this thread?

In my case.. On Specialized expander is written 9nm, on every other expander i found 7-8nm.. Deda state in manual 3nm.. If i want to use this Deda expander since it's longer what torque will u use in this case?

velocipedeimp
Posts: 97
Joined: Mon Mar 14, 2022 5:24 pm

by velocipedeimp

According to Deda, the torque setting is 7nm for the expander plugs - 45mm and 70mm lengths. Same for the Columbus 60mm expander.

MaxPower
Posts: 407
Joined: Fri Sep 20, 2019 9:30 pm

by MaxPower

velocipedeimp wrote:
Thu Apr 28, 2022 3:17 pm
According to Deda, the torque setting is 7nm for the expander plugs - 45mm and 70mm lengths. Same for the Columbus 60mm expander.
Interessting. Thanks for sharing

velocipedeimp
Posts: 97
Joined: Mon Mar 14, 2022 5:24 pm

by velocipedeimp

MaxPower wrote:
Fri May 13, 2022 5:39 pm
velocipedeimp wrote:
Thu Apr 28, 2022 3:17 pm
According to Deda, the torque setting is 7nm for the expander plugs - 45mm and 70mm lengths. Same for the Columbus 60mm expander.
Interessting. Thanks for sharing

Sure thing.

kmm
Posts: 1
Joined: Thu Sep 09, 2021 12:29 pm

by kmm

velocipedeimp wrote:
Thu Apr 28, 2022 3:17 pm
According to Deda, the torque setting is 7nm for the expander plugs - 45mm and 70mm lengths. Same for the Columbus 60mm expander.
The Deda manual states 3 N.m max! I tried that; of course, the plug was pulling out as I started torquing the top cap bolt. I tried increments of 1 N.m and at 6, it was still pulling (I was probably applying too much torque to the top cap bolt; more than twice the recommended 1.5 N.m...)

The Deda manual I am referring to is at https://dedaelementi.com/pub/media/wysi ... web-EN.pdf
See page 8.

ToileySiphon
Posts: 91
Joined: Fri Jul 19, 2019 2:58 am

by ToileySiphon

That's a topic in which there seems to be a lot of guessing, even from manufacturers.

When I got my Trek Emonda ALR, the plug slipped as it was probably undetorqued. I reached out to Trek to get the proper torque, they gave me a 8-10nM range, which seems to be on line with most of their documentation. So I went for 8nM with a freshly calibrated wrench. This bulged the steerer a little, just enough to be noticeable. Left it that way and haven't touched it for two years, everything seems fine.

Prior to that, I installed a specialized plug in another bike. Slightly under-torqued to 7nM - bulging steerer, rode like that for a couple of years.

I've read that carbon is supposed to be strong in expansion than compression (like a circular piece of cloth).

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steveadore
Posts: 386
Joined: Wed Mar 04, 2020 10:01 am

by steveadore

Reviving this thread: Is there some consensus on the correct torque value? The Deda site now suggests MINIMUM 5Nm for the 70mm version: https://dedaelementi.com/expander-70
But what is the optimum or maximum torque value? 7-9 Nm or so?

Those of you who have used this Deda expander, how to do you cut your fork steerers to length? The standard recommendation is for the top of the fork steerer to be around 3mm below the top of the stem (or the top of the spacer above the stem). But this Deda expander seems to add another 1.5 mm or so to the steerer, as its upper edge sits right above the top of the steerer. So would I need to measure 3 mm from the top of that metal edge?

PoorCyclist
Posts: 783
Joined: Wed Dec 07, 2011 1:26 am
Location: California's country side

by PoorCyclist

5nm should be safe, but I always set it looser than that just by feel. You can do 3nm put on the stem and top cap, load the bearing, remove all to check I bet it did not pull upwards at all. Easier to add more if needed than deforming everything then try to undo the mistakes.

For cutting just draw a sharpie with the stem on and then cut it, not cutting into the sharpie mark. Usually that gets you about 3mm with the expander on then put a 5mm spacer. If you want to go tighter, like 2.5 or 3mm spacer you better have a consistent and precise cutting process.

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steveadore
Posts: 386
Joined: Wed Mar 04, 2020 10:01 am

by steveadore

Just heard back from Deda. They've told me 5Nm is the magic number

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