Easy Star-Fangled Nut (SFN) Removal

[Danneaux]

Hi All,

In the event another of you need to remove the star-fangled nut (SFN) from your steerer, here are my suggestions to make it much easier than some other methods posted on the 'Net.  I needed to remove mine so I could replace it with Tout Terrain's removable adapter, equipped with a channel to allow the power lead to reach their "The Plug2" USB charging adapter installed atop my Sherpa's steerer ( http://www.en.tout-terrain.de/fileadmin/media/pdf/deutsch/dokumentation/bedienungsanleitungen/The_Plug_II_Anleitung_de_en_05_11_V1.0.pdf ).

SFNs were originally developed to hold tubing together, as in lawn furniture and portable scaffoldings.  By their very design, they are meant to be permanent and unremovable, either by accident or intent. Installing them is generally regarded as a one-way venture.

Nearly every other removal method advocates...

1) Punching the existing SFN lower in steerer and placing another above it (as in the event of improper placement or damage to the threads on the original).  This would not allow me sufficient clearance for passage of the TTTP2 charger wiring.

/or/

2) Punching the original SFN through the bottom of the steerer.  This will not work if the steerer is butted or if there is a fender mounting plate at the base of the steerer, as in the case of my Sherpa.

/or/

3) Drilling out the SFN using progressively larger drills until the assembly collapses and the pieces can be removed.

None of these were desirable on my Sherpa, and #3 would not work because as soon as one drilled through the peened "collar" on the upper SFN, the threaded spacer would simply spin atop the lower SFN, stopping progress there.  For the life of me, I do not see how this succeeded in the Tout Terrain video demonstration available here:  http://www.youtube.com/watch?v=5P097uHFfyY 

The method I use gives almost immediate results while greatly minimizing any possibility for damage or injury:

1) With the fork still in the frame and the bike laid on its side, remove the top cap from the steerer and any spacers above the stem.

2) Using an electric drill and a 5/16" (8mm) bit, drill-out the peened rivet atop the upper SFN.  Drill only until the peened "collar" parts, leaving the upper SFN essentially free of any connection with the lower, held in place only by friction against the steerer sides.  The threads in the spacer attached to the lower SFN will still be intact.

3) Insert a small hook-shaped device or the end of a drift punch into one of the holes between the "petals' of the upper SFN and twist gently from side to side. The petals on the upper SNF should deform and you can then tilt the upper SFN out and remove it with some needle-nose pliers.  Once tipped in the steerer, it should remove with surprising ease.

4) With the upper SFN removed, you will see the threaded spacer sitting atop and riveted to the lower SFN.  Insert a spare, standard 6mm x 1.0mm pitch bolt into the threaded spacer and use mole grips (Vise-Grips to 'Merkins) to tilt the bolt to the side.  The lower SFN will tilt with it.  As soon as it is tilted about 40 degrees, grab the edge with some needle-nose pliers and gently lift it upward, free of the steerer.

You will be left with no damage to the interior of the steerer beyond the original light scoring caused by installation of the SFN. You may now replace the original SNF with another, or with a removable substitute anchor such as Tout Terrain's ( http://shop.tout-terrain.de/epages/es117678.sf/de_DE/?ObjectPath=/Shops/es117678_tout_terrain_Zubehoer/Products/837-011-022 ), which works on the principle of an double-expanding cone, much like the bottom of an expanding-cone quill stem.  Be sure to coat the removable anchor lightly with anti-seize compound to prevent galling and aid in future removal.

As a final note, it is possible to install the power lead for "The Plug 2) if the petals of the original SFN are aligned and if they are of sufficient size to pass the lead.  Unfortunately, mine were a bit slim to allow this, requiring removal and replacement with Tout Terrain's substitute.

In the event my photos upload out of order, I've marked them 1, 2, and 3 to show the proper sequence.

Best,

Dan.

[julk]

Dan,
That is brilliant and I will use it if and when I go for a TT Plug2 or maybe Plug3 by then.
It is great to see an analytical engineering mind at work or is that at play?
Many thanks for posting the idea.
Julian.

[Danneaux]

Thanks for the kind words, Julian.  I may occasionally post illustrated technical tips as they become relevant to forum threads.  For example, I never use 3rd or 4th hand brake tools on tour or in the shop; my technique just doesn't require anything but a hex wrench and perhaps a rubber band or folded business card.  While I love using "proper" tools, improvisation at home makes it a done deal when required on the road!  I'm sure there's lots of tips and tricks we've all picked up over the years or developed in response to need.

This is a terrific forum whose members comprise a wonderful resource and a supportive community of like-minded enthusiasts.  It is nice to be able to sometimes give back in return for what I've gained.  I have learned and gained from every other contributor to the list.

All the best,

Dan.

[julk]

Dan,
Coincidence - I was fitting new brake cables yesterday and was using a Park 4th hand tool to get the cable just the right length before nipping up the fixing bolt.

I usually just do it by hand, but wanted to avoid squashing the new cable in the wrong place.

What technique do you use?
Julian.

[Danneaux]

Hi Julian,

I'm glad you asked! My HKC 4th hand is my most-used tool...for tightening zip-ties properly! My 3rd hand gathers dust on my toolboard.  I found I only used them to fight spring tension.  Eliminate spring tension, and brake cables can be tensioned and pads replaced more quickly and accurately by hand in a fraction of the time.

My technique varies a bit depending on whether I am dealing with sidepulll, cantilever, or v-brakes, but the essence of it depends on first releasing return-spring tension, then fixing the cable lightly to the anchor -- just enough to hold the brake in place -- before refixing the tension springs and tightening the anchor bolt home.  All of this is done with the idea of leaving the adjuster a bit slack to allow for additional takeup or release if needed.  Centerpulls can usually be done with the springs tensioned; it just takes a bit more effort to get it right, but is easy provided you allow enough slack in the straddle carrier to seat the free end of the transverse cable.

I like to leave my brake cable adjuster screwed out just a little way.  Why, if cables stretch, pads wear, and excess space needs taking up?  Well, the answer is simple enough -- I want to be able to take up slack if needed, but I also want to have enough room to open the brakes up a smidge in the event the rim goes wowzers from an impact or other damage.  Crashing through an unseen pothole at night, striking a fallen rock as it rolled down a hillside and across the road, and having a blowout so severe as to knock the rim out of true are all incidents that made me happy for a bit of extra clearance I could dial in on the spot, saving the wheel truing for later at home or camp.

As mentioned, my technique varies depending in the brake.  For centerpulls, I slide the straddle up the cable and anchor it lightly at a point that *just* allows me to engage the straddle cable in the the brake arm eyelet.  For cantilevers, I do much the same, leaving *just* enough room to catch the leaded end of the transverse cable beneath the arch on the free canti when I squeeze the pads against the rims.  I do this on both types of brake with the adjuster screwed fully home, as there is some slack in the system that will need taking up.  I will sometimes use a folded business card to preset the needed pad-to-rim clearance.  If all goes right, that will equal my desired 1-5 to 2 turns of the adjuster (thew amount needed to fully bed the housings against their stops and secure the leaded ends in their lever stirrups).  Sidepulls, cantis, and v-brakes are a bit easier 'cos there isn't a straddle wire to deal with, and I only need to hold the one arm/pad against the rim as I use the free end of the cable to equalize the tension and pull the opposite pad to the rim.  I gauge rim clearance from one side...doubling the overall clearance.  For example, if Shimano specify 1mm rim-pad clearance for each side of their v-brake, I make sure I have 2mm on the side I'm looking at, the pad drawn fully against the rim on the opposite rim side.

Once everything looks right, I tighten the cable anchor a bit more, hook up the springs, and check everything over.  If the pads are a bit tight, I can either let out some cable at the anchor or using the adjuster.  After a final check, I tighten everything up solidly and I'm done.  This whole process is much easier thanks to modern die-drawn or double die-drawn cables that develop little stretch despite being much thinner than cables in days past.  It is harder to accidentally squash the strands out-of-round when one only intends to pinch them lightly, as the cables just don't distort as much. 

As for pad adjustment, I free the brake return springs and set the pads up on a slack brake, typically before I deal with the cable at all.  It is just so much easier, and makes adjustment a "go" the first time, even on otherwise problematic cantilevers.  A folded business card beneath the rear 1/4-1/3 of the pad sets the toe-in and I'm good to go.  In a pinch, a heavy rubber band will set toe-in, but because it is elastic, results can vary, so I prefer the card instead.  Rehook the tension springs, do the cable adjustment, and it's done.  Brake adjustments are just so much easier when one isn't fighting a return spring, and only one pair of hands is needed -- yours!

As an aside, I rarely use the centering tension screws on v-brakes, preferring instead to center them by lightly bending the linear tension springs directly by hand with the tension screws backed out equally.  I have yet to encounter a factory-supplied v-brake with equal spring tension.  Bending the springs is an easy remedy, and tension then stays very close to even for the life of the brake in my experience.  The tension adjusters are still there if needed, and can be used to adjust overall system return spring tension if needed (as might be the case if your mounting bosses have only a single spring-anchoring hole).

Since I learned to adjust brakes this way, it has become a quick and simple pleasure instead of a dreaded task, even while on the tour in the worst of conditions.

All the best,

Dan.

[julk]

Dan,
Thanks for that, much more than I expected.
I will try next time with the return springs released, sounds like a great idea.
Thank heavens for a good forum and generous posters!
Julian.

[troy57]

HI ,Im new here. I'm organising a trip to Brittany and wanted to fit a tout plug to my Thorn. These instructions were very good and with trepidation I managed to remove the sfn. Many thanks Danneaux.

[Danneaux]

Hi Troy!

Welcome to the Thorn Cycling Forums!

I'm just tickled to hear the SFN removal instructions helped someone!  Brittany is a gorgeous touring locale (some very good friends live off the N12 west of Saint-Malo; if they weren't currently on the other side of the world, I'm sure they'd welcome a touring cyclist like yourself in their lower field or back garden); you're bound to have a wonderful time. Eat well! The fresh breads in that region are something to really look forward to. If it is Wednesday or Saturday, look for an open market near a town square almost anywhere for fantastic produce.

I so hope you'll favor us with some photos on your return. The Forum has a gallery board here:
http://www.thorncycles.co.uk/forums/index.php?board=5.0

When you return, I'd love to hear how the Tout Terrain The Plug 2 worked for you. The Forum has a board and child-board devoted to just that topic ( http://www.thorncycles.co.uk/forums/index.php?board=10.0 ...and... http://www.thorncycles.co.uk/forums/index.php?board=32.0 ). I think you'll find the TTTP2 charger to work very well with a minimum of fuss. I am still amazed at how I can just "plug in" and a short while later...my gadget is charged. I made my own charging adapters so my non-USB gadgets can charge, too. A compact electric shaver is a pretty nifty take-along. No cold-water on the face at dawn, and less weight than ca can of shaving cream. Away from the mains? The charge lasts a couple weeks of use, and the TTP2 recharges it in about two hours' riding time. If sounds long, but if you're going to be riding anyway....

Happy, safe, fun trip-wishes your way!

Best,

Dan.

[troy57]

Hi danneaux, thanks for your reply. Unfortunately i managed to mangle up the tout whilst fitting it. When I tried to tighten up the headset i rounded off the nut.  Then I attempted to drill it out and along the way mashed up the plug. Then i tried to tighten up the headset and it wouldn't have it which was why i overtightened in the first place. Adding the expander made the steerer longer which required an extra spacer which I didn't realise at the time. I managed to scrounge a spacer off another bike of mine and get the Thorn steering sorted. I've also ordered another plug. expensive day !

Any idea how I can charge up Tenergy 3v batteries ?

Thanks for the tips and I will do my best to put up some photos.

[Danneaux]

Unfortunately i managed...

Oh. Ohhhhh, man. I feel your pain. I don't think there's a single one of us who have not messed-up somehow in the course of installing a part at some time in our career. I once got a faulty torque wrench. It did a dandy job of signalling when I had exceeded the proper torque. Uh-huh; it suddenly got easier to turn and half the bolt was left in the threads, the other in my hand as a remembrance.  Of course, I used the new, very expensive torque wrench for the first time on the new, very expensive component. Trashed two spendy things in one go; that's efficiency!

These experiences come with another bonus in the form of a free language course. I have sometimes put-together common words in uncommon ways as a result.

As for the Tenergy's...you're in luck! They are rechargeable 123A batteries, and there are a number of USB rechargers available for them. I don't have a set so I can't make a personal recommendation, but enter "123A USB charger" in Google or eBay and the hits just keep coming. If you don't have luck, give a shout and I can come up with some specific links for you. I'd just place the batteries in the charger, putthe charger in my HB bag, and connect the lot to the TTTP2 with a USB cord and call it good. Do be aware, different USB cords do vary in resistance. If you're not getting the results you wish from the TTTP2, change the USB cord first before going after The Plug. It's very likely the cord, and a simple swap will do (if you have a volt-ohm meter, it is easy to check and compare the resistance...the problem is usually at the end. Inside the molded lug cover. Where you can't get it to fix it. A replacement is the usual cure).

All the best,

Dan.

[troy57]

Hi Dan, Thats brilliant. Every cloud etc 

The plug is actually fixable I think if you're good with a soldering iron.

Again some great ideas especially the usb chord thingy.

I'll tell you how I get on.

Troy

[troy57]

Sorry , I'm in the uk and I can't find them. Any help would be appreciated . They are lithium batteries.

[Danneaux]

Troy,

Might the ones listed here in ebay.co.uk work for you?
http://www.ebay.co.uk/sch/i.html?_trksid=p5197.m570.l1313&_nkw=123A+USB+charger&_sacat=0

And, this thread listing British sources...
http://www.britishblades.com/forums/archive/index.php/t-134542.html?s=5d391664bd477dae776bea88b008e169

Another UK source...
http://stores.ebay.co.uk/hkequipment/Chargers-/_i.html?_nkw=rcr123&_fsub=16553775

You can use this Google search I customized for you to find other rechargeable CR123 USB chargers:
https://www.google.com/#hl=en&safe=off&sclient=psy-ab&q=rcr123A+USB+charger+.co.uk&oq=rcr123A+USB+charger+.co.uk&gs_l=hp.12...0.0.6.355126.0.0.0.0.0.0.0.0..0.0...0.0...1c.fBhf3XOKX3g&psj=1&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=e48c354da497c1c4&biw=1173&bih=574

If you wish to make your own Google searches limited to UK sales sources, just enter ".co.uk" (no quotes) with Boolean operators in your search string, and there ya go.  

Hope this helps.

Best,

Dan.

[troy57]

That's great , full of useful info as  usual. Thanks a lot.  I'm very excited about getting all this working. I'm not sure I'll have time to order and receive the charger until I get back. But I certainly will. I'm leaving on Monday

[keleher]

Just wanted to add my 2 cents. Once Dan explained what "drilling out the peened rivet" meant, I was able to follow his instructions and get it done in 15 minutes, despite being *very* cautious. I had to switch from an ordinary bit to a masonry bit to make progress, but this worked quite well.