[Closed] Snapped fork steerer - anyone ever seen this happen?

😯

Ham fisted overtightening of stem?

Snapped a one inch steerer at the crown BITD but never at the top like that... *doffs hat* well done sir!

overtightened stem bolts?

How tight was the stem done up and how much steerer was in the stem?

How much steerer was in the stem was my first thought but if you look closely, you can see that the open back of the stem itself is still filled in with the snapped off steerer.

Valves out of line with tyre logos?

I can see that now I have had a closer look.

Star fangled nut damage inside the aluminium steerer?

What kind of forks were they?

What forks are they?

Have the forks been on another bike with a longer headtube and a Chris King headset which has scored the steerer tube right where it has now failed?

😯 That is odd.
I would have though that overtightened bolts would cause a clean shear, not the shape of the the break shown (but that's guesswork on my part)

Possible that weather had something to do with it? Maybe some water got in there, froze, and caused extra pressure?

I asked the same question about what kind of forks they are. I don't recognise them (this despite my geeky encyclopedic knowledge of bike kit!) 😀

I asked the same question about what kind of forks they are. I don't recognise them (this despite my geeky encyclopedic knowledge of bike kit!)

Ahhh Watson, a clue!! The hunt is on!! 😉

 

Er... how do you quote? 😉

you need to close the quote with

but back on topic. never seen one like that...

you need to close the quote with but back on topic. never seen one like that...

Thanks!

It will polish out 😯

I've snapped my road bike mid steerer JRA.

The fact I'd ridden it down the beast the day before might have had something to do with it though.

It is cracking season! Don't ride your bikes!!!!!!! 😯 😆

far too many spacers under the stem imo

Nice to see someone else on an Enduro Elite

Did the same a couple of years ago coming off Blencathra:

[img] http://www.flickr.com/photos/parkedtiger/8411140136 [/img]

http://www.flickr.com/photos/parkedtiger/8411140136/

Apologies - it's not too clear an image, but the steerer broke just above the star fangled nut in a very similar fashion to the OPs. Forks were 140 Bombers, about five years old; no other signs of damage from the SFN and the stem bolts weren't overtightened.

thisisnotaspoon - Member

I've snapped my road bike mid steerer JRA.

The fact I'd ridden it down the beast the day before might have had something to do with it though.

Good effort 😀

Did the same a couple of years ago coming off Blencathra:

That picture looks like it was taken at night. Fair play for riding up and down Blencathra on a night ride!

From the picture that could be an old Manitou Sherman/Travis/Nixon fork?

Was the headset delievered a day late due to snow? That's probably your problem.

Seen several of forks having done that, usually due to scores, earlier damage crash/bad installation or actual material defect.

lights too powerful..

Too many spacers. Correct amount = 0.

That picture looks like it was taken at night. Fair play for riding up and down Blencathra on a night ride!

Night time = no walkers 😉

If he takes off the spacers he can keep using that fork 😈

This happened to my riding buddy a few months ago (Darkcyan on the forum). The steerer on his Fox Talas forks snapped in the same place with a very similar looking tube breakage. Incidentally he was also using a Chris King headset although there was no evidence that it had casued any damage or scoring to the steerer tube. Since the tube was now too short to use with his frame he had to send the forks back to Mojo to have the whole fork uppers replaced; they come as one unit steerer, crown and stantions. I don't think this was mega-expensive and was far more economical than replacing the forks, especially as they serviced them at the same time. The breakage occured landing a small log jump but certainly nothing that should cause a steerer failure. More importantly he wasn't injured!

Yep i had exactly to same mate!....
Christ knows how....was your mate using a headlock bolt through thingy instead of star fangled type topcap????.... if stearer was a tad too long the headlock would effectively squash headtube when tightening the capbolt,thus cracking headtube....thats the theory i came up with re mine anyway......i cut damage off stearer & sold fork as was perfect after damaged part removed from steerer,& bought nother pairv forks with longer steerer....what a pisser it was!.... new years eve 2 yr ago i discover it..ARRGGGHHHHH!

There's some left take the stackers off an cut it straight then just put stem on front end will just be lower

you were lucky. My alu steerer tube snapped 100mm up from the fork crown within the headtube, I have a false tooth and about 48 stitches because of this, about 25 inside my mouth and the rest on my face. Plus a hatred of a certain fork manufacturer.

ti_pin_man - Member
you were lucky. My alu steerer tube snapped 100mm up from the fork crown within the headtube, I have a false tooth and about 48 stitches because of this, about 25 inside my mouth and the rest on my face. Plus a hatred of a certain fork manufacturer.

^^^^^^ OUCH!

Is there a nail in the tyre?

Seriously though, no idea other than stuff that's been suggested. Good effort though.

Thanks ti_pin. Now I'm going to get the sh1t's about my steerer tonight 🙁

That's real interesting.

Is your post a "just out of interest post"? or are you looking to determine the reason for failure for a warranty challenge?

I would be interested to know how old the forks are. If you have a good macro lens a close up of the fracture surfaces would be very useful to provide some clues as to the reason of the failure. when things like this happen, its always tempting to put the two pieces back together to see how they fit, however this can destroy some of the "evidence" which tells the tale of the failure.

Snapped fork steerer - anyone ever seen this happen?

once.

messiah - Member

Star fangled nut damage inside the aluminium steerer?

was the culprit - either that or just a total coincidence that the crack lined up with the star-nut.

Is your post a "just out of interest post"?

It was; I don't know the person who owns the bike, I am just connected to his mate who posted the picture through another friend.

Nevertheless, your post has stimulated some discussion and also brought to light similar problems which others have had. Would be interesting to know just how many steerers are failing like this.

ahwiles has mentioned that that his star fangled nut was the culprit in his case. Sounds highly likely. Overtightening of these can put an indent into the inside of the steerer, this can serve as a crack initiation point and lead to this type of failure.

dday, the fork manufacturer said these need to be serviced annually, its the steerer tube ffs, what exactly do you service on a steerer tube. My belief is that the steerer simply failed. Its worth a check of the steerer every now and then IMO.

I could post the picture of my face but people will have just had lunch.

[img] [/img]

Big George wondering how he's gonna tell Lance about breaking on of his bikes...

Too many pies ❓

ti_pin_man, you've been Paced by any chance?

northwind - - and the prize goes to ... your good self

Sigh - looks like we all need 1'5 steerers now - where's my credit card....

Some of us never gave up on the 1.5" steerer... the industry will come back round to it in a while 😉

2005 Enduro Elite came with 145mm Nixons fitted

I've a set of forks with the steerer quite scored all the way round it , I was a bit concerned but it seems ok touch wood , its pretty thick steel but this makes me think 🙁

It's definitely a sticker.

This happened to me with a set if manitou skarebs. I pulled a little jump over a log in Chopwell carpark while waiting for the rest of the lads to arrive and the steerer snapped. I bailed off (as you would). As I stood up very perplexed about what had just happened, one lad said he thought I was practicing falling off. Spoilt my ride that did.

If you have a good macro lens a close up of the fracture surfaces would be very useful to provide some clues as to the reason of the failure

Probably won't be powerful enough to tell you anything useful, other than a possible initiation site, although people often identify the intiation site pretty much as far away from where it really was. We normally look at fracture surfaces with an optical microscope and then an SEM to find potential microstructural flaws that might lead to a failure.

Did he buy it from uk bike store?

nah, if he had, he wouldn't have been riding it last weekend to snap it, as it would not have arrived yet.

What should we be torquing our steerer bolts up to then?
I always do it as tight as possible. Never understood why steerers and stems aren't splined.

I'm not sure that it is established in fact that "overtightened" stem bolts or steerer bolts have caused this, so if I were you I would carry on using the manufacturers recommended settings.

ti_pin_man - Member

you were lucky. My alu steerer tube snapped 10mm up from the fork crown within the headtube, I have a false tooth and about 48 stitches because of this, about 25 inside my mouth and the rest on my face. Plus a hatred of a certain fork manufacturer.

I'm finding a safer hobby.

Thanks mr overshoot for dragging up my old scars. I haven't seen that picture for a while and it nearly put me off me dinner...

Bigjim - I'm still riding, gotta be done, cycling is just part of who I am, I guess we're all the same otherwise we'd be on knittingtrackworld right now! Lol.

To be fair Joe ,you looked better after the accident tbf 😉

Seriously dudes.. I'm surprised none of you have got what caused it..!

It's caused by bimetallic corrosion of the inside of the steerer due to intimate contact with the star nut.

The star nut scrapes the anodising away when it's bashed in, and gets a fair amount of spray up from the wheel in winter, with lots of yummy salt. The steerer has eroded away from the inside. It's the same with those pace forks. Look at how rusty that crown race seat is.

It's best to take the top cap off occasionally and squirt some spray grease round there, or better still, never use a star nut in the first place on an aluminium steerer. Hope head doctors rule.

Go now and take your top cap off and have a look... You'll be appalled at the state inside!

Well said Ti Pin Man. Myself I'm two clavicles, four vertebrae, one humerus, one wrist and multiple soft tissue injuries into my cycling odyssey.

It aluminium, the more you use it the weaker it gets and they look like old forks. Headset, starnut, spacer etc were probably more the straw that broke the camels back. loads on top and bottom of the tube will be high.
good effort sir...

Enough to make me swap my SFN's to those long Ameoba headlock things. At least if it goes the bolt will holdit together.

I snapped a BMX stem once, landing a jump. Bars went forward leaving jagged stem that ripped in to my chest, face hit the tyre & rubbed along it for few secs. Tried to grab the fork legs to right my self but knuckles ended up skinned by Skyways. Managed to roll off sideways.
Not a good day. I looked a state. Managed to ride home no handed holding the severed bars.

Big George wondering how he's gonna tell Lance about breaking on of his bikes...

True and dull story: I was sitting in a bar in Roubaix when that happened, watching on the telly, and Roger Hammond's missus was there too, having wandered up the road, found the bar, and found us chatting in English. What I learned that day: Having a significant other racing in Paris Roubaix is a nerve wracking experience. When his teammate's bike explodes, you go a very pale colour

I got what caused it. They werent that old when they snapped, maybe a couple of years old, but in the UK winters parts can quickly look scruffier quickly. My own 'snap' did happen some time ago and these are old pics. Not sure when the OP's snap occured. Allegedly we should 'service' rigid forks annually... this really surprised me, everybody I rode with at the time (many on rigid SS) and all the road guys I've ever ridden with. I think a few nervous checks were performed by all afterwards. 😉

my next purchase after the snap was some ti forks. 🙂

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[url= http://www.flickr.com/photos/90489422@N06/8414064900/ ]Broken shivers[/url] by [url= http://www.flickr.com/people/90489422@N06/ ]Alpine160[/url], on Flickr

Old Shivers on friends bike a few years ago.
Cwn carn downhill track. Last run of the day. On the section where there are 3 steps a bit after the tunnel.