Steerer tube too short?

Discuss light weight issues concerning road bikes & parts.
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Lightweenie
Posts: 153
Joined: Sun Aug 03, 2014 1:00 pm

by Lightweenie

Hello all,

I built a commuter/winter-bike mostly from my parts-bin. The issue is that the fork was cut some years ago for a different bike with internal bearings, and it is 1-2mm shorter than the top of the stem edge, see the pictures (this is with preloaded bearings).

ImageDSC_0566 by AAntonios, on Flickr
ImageDSC_0564 by AAntonios, on Flickr
ImageDSC_0563 by AAntonios, on Flickr

Is this on your opinion a big problem? It seems ok for commuting to me, especially since the stem clamps a bit lower, but I'd still be afraid to do some longer-steeper descents. Would you personally fix it or leave it as is?

Now, if I decide to fix this I'd not like to replace the fork (it is 320gr cut and replacing it with something equally light would be expensive for such a build). The easiest solution would be to replace the top of the external headset bearing which seems to be quite tall (see next picture). Where can I find such a top for replacing though?

ImageDSC_0568 by AAntonios, on Flickr

The second idea would be to replace the stem. This one has a stack of 40mm. Any recommendations for some light&cheap stem with a stack of roughly 38mm?

chiumomo
Posts: 73
Joined: Tue May 29, 2012 1:38 pm

by chiumomo

Image

Try using headset compression plug with a lip, that might help.

by Weenie


Delorre
Posts: 867
Joined: Sat May 24, 2014 12:09 pm

by Delorre

Seems OK to me. In most manuals, you will read to cut the steerer 1 or 2 mm lower than the top of the stem to alowe some space to the topcap.

mattr
Posts: 3412
Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

What fork is it?
Some (very few) require that the steerer is proud of the stem. 95% or more require that it be something like 3mm below. Like yours.

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Lightweenie
Posts: 153
Joined: Sun Aug 03, 2014 1:00 pm

by Lightweenie

It's a fork that came with my (now taken out of traffic due to corrosion) 2004 carbon/aluminum Merida frame. Nothing really special, but still a quite light fork. It is full carbon with aluminum dropouts.

nathanong87
Resident master of GIF
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by nathanong87

looks good in my opinion. Just need to make sure that your top cap clears the steerer when u compress. different designs of top cap might bottom out on the steerer.

but all of my steerers are cut that way under the top of the stem , and are fine , and looking so pro

WannabeWeenie
Posts: 105
Joined: Mon Aug 03, 2015 7:05 pm
Location: Minnesota, USA

by WannabeWeenie

As others have said, 1-2mm below the top of the stem should be fine.

If you would still like to go the route of replacing the upper bearing, Cane Creek's AER range has some very low profile options.
http://www.canecreek.com/products/headsets/aer

Marin
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Joined: Wed Jan 22, 2014 11:48 am
Location: Vienna Austria

by Marin

If it's any longer you'll need a spacer on top of the stem so the top cap doesn't bind against the steerer. I'd say it's perfect as it is.

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Lightweenie
Posts: 153
Joined: Sun Aug 03, 2014 1:00 pm

by Lightweenie

Thanks for all the responses. As I wrote it is 1-2 lower after bearing preloading.

I do like the idea of the compression plug with a lip, might try it. But I feel more confident after all the replies. :)

5 8 5
Posts: 1353
Joined: Sat Jul 29, 2006 2:36 am
Location: UK

by 5 8 5

As others have said it should be okay. The upper stem bolt isn't too high up. Make sure you fit a compression plug.

What make of headset is that? It looks like it has quite a high profile.

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Miller
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Joined: Thu Sep 21, 2006 8:54 pm
Location: Reading, UK

by Miller

One option would be to find a stem with a lower height, stems do vary in this regard.

My opinion is that the most secure clamping, in what is a high stress area, is when the fork steerer has some height above the top of the stem and the steerer is supported internally by a compression plug. This approach does mean having a spacer above the stem which will not look so pro. (Do pros actually care about that?)

hambini
Posts: 117
Joined: Tue Nov 15, 2016 8:13 am

by hambini

Miller wrote:One option would be to find a stem with a lower height, stems do vary in this regard.

My opinion is that the most secure clamping, in what is a high stress area, is when the fork steerer has some height above the top of the stem and the steerer is supported internally by a compression plug. This approach does mean having a spacer above the stem which will not look so pro. (Do pros actually care about that?)



I'd agree with this. I think one spacer above the stem is the best way, you don't have an area of "nothingness" for the stem to compress against.

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Calnago
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Joined: Sun Nov 07, 2010 9:14 pm

by Calnago

You are fine with that set up. If the top of the steertube was at the junction where the top stem bolt clamps to the steerer, I'd be more concerned. Typically, I like to leave just a "lip" above the steertube to 1) ensure that there is complete contact for the entire stem and 2) provide an "anchor" for a 5mm spacer so that it doesn't move around. The spacer also ensures there is room enough for the top cap to provide pre-load. As for what the pros do, this is (used to be) the preferred method in almost all cases. Some stem manufacturers like FSA would insist on a spacer above the stem. Trek would insist on a spacer above AND below the stem. It's really all over the board now, depending on design. If the top of the steer tube is too low (like where I mentioned at the intersection of the top stem bolt, and if it is unsupported by way of a solid insert or something, you run the risk of slightly crushing the top of the steer tube into a slighty cone shape, which in turn creates an upward pulling effect on the stem and the whole thing becomes a lot more prone to loosening up as the stem works it's way "up the cone".
But I wouldn't worry in the least in your situation.
Other stems that I know of currently, might be the new Deda SuperZero. It has a stack height of only 36mm... one of the reasons I did not use it on my last build. Not due to structural reasons, just that I wanted the future flexibility of using stems of the more standard 40mm stack height without having to remove spacers or otherwise reposition the stem on the steertube. I'm presuming in your current setup you are still going to use some kind of insert to be able to apply a preload with the top cap and bolt.

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Lightweenie
Posts: 153
Joined: Sun Aug 03, 2014 1:00 pm

by Lightweenie

Thanks all again for the responses!

@585: it is a Ritchey Logic EC34. Yes it is quite tall indeed, I think this is where the problem stems from

@Calnago: yes, I have a quite massive FSA compression plug. I just removed it for the pictures.

I might try a compression plug with a lip that I have somewhere, as chiumomo suggested. It seems though that the consensus, is that it is OK so I'll see if I do it or not. Since I would like a slightly narrower handlebar and the current stem is for 26.0mm bars I might get a cheap Kalloy UNO or something to replace it (which from I read in another thread also has a stack of 40mm). We will see.

by Weenie


ryanw
Posts: 324
Joined: Sat Apr 16, 2016 6:52 pm
Location: London

by ryanw

Looks absolutely fine to me.
'16 Cervelo S5 - 6900g
'17 Focus Mares Force 1
'15 Scott Addict Team - 6850g Sold
'17 Cervelo R3D DA - 7580g - Sold
'16 Cannondale CAAD12 DA Disc - 7560g - RIP

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