About to go out for a ride this morning but decided to swap the stem before hand. Bloody good job as I found a crack in the steerer tube. It looks like the hope head doctor had slipped up the steerer when I tightened the top cap when I fitted the previous stem. Being at the top of the tube it was able to flare the end and start the crack.

I imagine I would have lost a few teeth if the crack had gone horizontal and snapped off.

Anyone else had this happen, and successfully had it welded?

Nope. Time for a new fork or steerer if you are lucky.

How the deuce did you do that?

How the deuce did you do that?

I’m no engineer but I believe the technical term is ‘ham fisted pillock’

Head docter tightened up to much, where the crack has started looks to be either the start or end of the hacksaw cut.

Over time the tube has split, new tube/fork/fork uppers required.

It’ll polish out – good job it wasn’t somewhere you can see it!

I have nothing to contribute other than to congratulate you on your choice of headset.

played sir…

Technically, anything metal can be welded, but whether it would be worth the hassle is another thing. More to the point, would you ever be confident in it again?

How long is the steerer?

If there’s enough left for use on another bike saw it off and eBay it.

I don’t imagine you’d be able to weld that, as it’s a split along the length of the tube. You might be able to get something like a zero stack headset and chop the steerer below the split?

I have nothing to contribute other than to congratulate you on your choice of headset.

Goes with my colourway innit, besides onza do surprisingly good headsets.

I like the idea of cutting the steerer tube and getting a zero stack headset, I always thought they were the same as integrated? I’ll do a bit of browsing on crc.

Cheers guys

Surely, as the stem is clamped around it, it will be ok. Especially if you were to remove the spacers and clamp the stem almost below the crack. ??

That is ruined. Buy a new fork or start saving for private dental work. Your choice…

can you just wrap some tape round it?

Silicone spray and a couple of tie wraps, job sorted

Personally, i’d drill a small hole at the end of that crack to take the pressure off it, put the stem back on, and carry on riding it.*

*may cause some / all of the following outcomes:

-death
-tooth loss
-memory loss
-death

Technically, anything metal can be welded

Mercury?

Mercury

Absolutely, at the right ambient temperature… Sodium may be a challenge though.

I used a similar FSA expander plug (10 years ago mind) and had a similar problem. Now I only use SFNs as they just work, and are less hassle.

Despite a crack appearing, I rode the fork for another couple of years. Only stopped when that bike was stolen!

I believe the same principles apply:

[video]http://www.youtube.com/watch?v=mVM-Oi2YP_I[/video]

I had a pair of forks where the custom frame builder had cut the steerer about an inch too short. I couldn’t get him to sort it (long story) but in the end I had someone make me an aluminium ‘plug’ which he bonded into the existing steerer. It had the same outside diameter as the steerer, with the lower section milled down to the internal diameter of the steerer, and then it was bonded in with some fancy Loctite or 3M adhesive. It also gives a stronger tube for the stem to clamp onto. I can’t quite remember what happened to the star fangled nut – perhaps the inside of the plug was threaded, or maybe the SFN was able to be placed at the correct height in the fork steerer below the plug. I hope that helps – if you can understand it!

I don’t understand what’s happened there. I may be wrong (and this being STW, somebody will tell me if I am) but I thought the purpose of the top cap was to apply a very light preload to the stem / spacers / top bearing, just to make sure there’s no slack, before you tighten the stem bolts. Thereafter, all the top cap does is make the bike look neater and reduce the injury if you try to impale your body on the steerer. So all the star nut or the Hed Dr has to do is hold that very light preload. Hope supply the Hed Dr with a very weak bolt, partly to save weight and party because it stops anyone overtightening it.

The stem is clamped hard around the steerer – this should mean the steerer is in compression, so how can it crack? One thought is that if the stem isn’t a good fit on the steerer, tightening it could ovalise the steerer (squash it from the sides), leading to cracks on the front and/or back of the steerer.

Hope supply the Hed Dr with a very weak bolt, partly to save weight and party because it stops anyone overtightening it.

this. The bolt is ally and the threads strip if you look at them wrong.

Don’t know about the hope design.

The late nineties FSA design had a steel bolt in the lower expanding plug (which I overtightened). The upper top cap type bolt was a wide diameter alloy bolt.

In my defense, it was a long time ago when aheadset type headsets were new. It was my first attempt at using an aheadset type headset. I would be much more gentle now!

Greybeard – i think your right

After a closer inspection it seems it might have been the stem that caused it. The stem isn’t a very snug fit around the steerer, about 1mm clearance all round, so it has ovalised the steerer when it was tightened.

I will have about 175mm of steerer left when I cut the cracked section off which probably isn’t long enough for most bikes so I won’t get much for the forks on eBay. So now im looking for a cheap second hand frame with a short headtube, a medium on one inbred seems a likely candidate

Great excuse to build a new bike i suppose, every cloud eh…

175mm isn’t that short, most small frames it would probably be ok depending on headtube length and stem stack height, and many with an integrated headset would be fair game…

You could cut the steerer off so the cracked bit is removed. Then buy a low stack headset and run your stem with no spacers.

Obviously this will affect your handlebar height.. which you could correct that with a higher rise bar.

Thumbs up for Star Nuts – and not re-inventing the wheel.

Cheaper
Lighter
Simpler
and in this case…
Less destructive
Safer

ndthornton – well put. That could be applied to loads of “new” mtb parts.

Like gearboxes when normal rear mechs work well enough, and tubeless tyres for example.