Goldtec Hub Failure

For people, who are interested, I emailed Rob Torres about the lacing and he sent me this back:

You did build it right. You can cross the spokes any way your prefer really, the only exception will be if they interfere with the rear derailleur on multi-speed rear wheels, but that isn't a consideration in your case.

I'm sorry that you had this happen, but things do go wrong at times. From what I can tell from your photo is looks like the hub wasn't strong enough to take the stresses from the radial spoke(s) in the area where the failure occurred. This can happen because of a low-quality hub made with poor quality metal, the design of the hub, a flaw in the casting that was internal to the section and couldn't be seen, or a combination of all of those.

Several companies that make hubs warn not to lace them radially because of potential problems like what happened to you, even Campy warns not to lace their hubs radially for this reason and they use the best metals and have strong designs. And I did have an older Campy hub have a 'pull out' as this is commonly called (probably partly because the hub had been built many times with various lacing's before I settled on the half Crow's Foot lacing, all those lacing's had stressed the hub flange many ways). But with my present rear wheels that I have Crow's Foot laces, a Campy for my road and Shimano for my mountain, they have done fine.

It could have been a manufaturing defect that causes what happened to you since the hub's makers say the design is strong enough for that type of lacing, an air bubble or an impurity in the metal what was hidden by good metal would have caused something like this and not been detectable through normal quality inspections.

While you can lace a pattern like the Crow's Foot, or any pattern really, with spokes alternating or not, there usually isn't any absolute reason why you have to one way or the other. If you had alternated the lacing it would not have prevented what happened.

Is it possible that having three spokes crossing at the same point, all laced heads-in, has caused this?

The tensioning/detensioning cycle the wheel goes through while turning under load, could act to stress the hub flange lateraly. I imagine the hub shell is'nt designed to undergo this sort of stress cycle. Radial heads-in causes the same stress, but not with three spokes focusing the stress to the same point on the flange. Pure speculation though, as I really dont know much about the crows-foot pattern. For patterns with no crossing or crossings away from the flange. I would have also gone with heads-in for the improved bracing angle.

Just some thoughts. Still most likely a defect. Good to hear your being sorted with a replacement.

(ED: If the spokes are 'unhappily' crossed. Should'nt a spoke elbow fail before the hub flange?)

(ED: If the spokes are 'unhappily' crossed. Should'nt a spoke elbow fail before the hub flange?)

That's what I was thinking.

It is possible that it was my fault but I asked (^) the guy who wrote the tutorial I used and he said that it was no problem to do it like that. Well, it has led to problems but I dunno what was the cause.

Johnny and broken777 have had their flanges cracked with 3cross.

With a bit of imagination you can picture the two crossing spokes pushing on the radial spoke of the triplet, which transmitts this to the edge of the flange. In reality the forces should be too small, and the the bracing angle far too small, for this to cause the failiure (IMHO). I've heard loads of postive reports regarding the quality of Goldtec hubs, maybe they are having problems controling this quality?

I'd be interested in seeing some stress images of some hubs with different lacing patterns. Surely there are some out there on the interwebs.

With a bit of imagination you can picture the two crossing spokes pushing on the radial spoke of the triplet, which transmitts this to the edge of the flange. In reality the forces should be too small, and the the bracing angle far too small, for this to cause the failiure (IMHO). I've heard loads of postive reports regarding the quality of Goldtec hubs, maybe they are having problems controling this quality?

I'd be interested in seeing some stress images of some hubs with different lacing patterns. Surely there are some out there on the interwebs.

You do mean in bending, right? I think that spokes are so flexible that you can assume they only transmit tensile forces. At least, that's what I would do if I were building an FE model of a wheel. (Sorry if I missed something).

Where is that contour plot from? Looks very interesting.

You do mean in bending, right? I think that spokes are so flexible that you can assume they only transmit tensile forces. At least, that's what I would do if I were building an FE model of a wheel. (Sorry if I missed something).

Where is that contour plot from? Looks very interesting.

Yeah, badly worded. I meant the inside of the elbow of the spoke is pushed against the flange, due to the bracing angle.

The pic is from here:
http://www.m5-ligfietsen.nl/site/EN/_m5__Lightweight_bike_parts/Front_and_rear_hubs/sAction:addtoshoppingcart/jump:1432/art_id:1432.2/quantity:1/custom:

Was tempted to use these in my road wheel build. Very light, and well priced, but I cant seem to find a source of straight pull bladed spokes.
)
)
I'll probably go with a Tune MAG 180/ MIG 70 combo instead.

Does the stress patteren really matter that much... Why not just get hubs that don't suck and use any patteren you like? ;)

After several threads about goldtec's breaking I for one will never get one... I'd rather run on-one's - actually I do atm on my winter-wheels, and the cheap hubs never failed me.

Why get expensive shit-hubs when you can get cheap and nice Miche?

Does the stress patteren really matter that much... Why not just get hubs that don't suck and use any patteren you like? ;)

Its mostly bike nerdism.
But the fact is most hub manufactures dislike radial spokes. Whereas most OTP road wheelsets these days have loads of them. This doesnt quite add up to me.

After several threads about goldtec's breaking I for one will never get one...

I've read far more positive reports regarding Goldtec hubs, and weighing up the weight/cost/durability(OK mute point on this thread). They're pretty impressive.
http://weightweenies.starbike.com/forum/viewtopic.php?t=50133

I'd rather run on-one's - actually I do atm on my winter-wheels, and the cheap hubs never failed me.
Why get expensive shit-hubs when you can get cheap and nice Miche?

I've a set of Shimano Deore's which I no idea have many miles I've put on them. I've moved them from beater to commuter to winter bike etc. and lost track over the years. I almost didnt want to open them up to service them before winter, in case I broke the spell.

Its mostly bike nerdism.

Yeah, with some engineering nerdism thrown in too :-) I have been idly considering doing some FE modelling of bike components. I'm sure it has either already been done, or isn't financially a viable idea. Which is a shame, although I haven't actually researched it much yet.

I've a set of Shimano Deore's which I no idea have many miles I've put on them. I've moved them from beater to commuter to winter bike etc. and lost track over the years. I almost didnt want to open them up to service them before winter, in case I broke the spell.

Oh good. I just got some Deores for my MTB and I can't be bothered to buy more hubs anytime soon...

Well, yesterday my new hub shell arrived. You can say what you want about BETD, but can't really fault them on their service.

Good on 'em. You gonna build it up silly again? :)

I'm not sure that I deserved it though, but as a sacrifice to the Wheel Gods, I will re-lace my wheels into ordinary 3-cross, if I really get this hub shell.
.

hehe

Does anyone know how to get the old axle and bearings out? I have the feeling I'm majorly fucking up the old one. mdcc_tester suggests just using my fingers but that definitely ain't working.

you need to pop off that cover with something, then just tap the end of the axle, one side of bearings should come out, then put axle back in and tap out other side.

That cover ain't shifting. I have already bent it. Keep going?

er i don't know then. pliers wrapped in electric tape to not scratch it?

That cover ain't shifting. I have already bent it. Keep going?
Could just be seized with crap. Have you tried spraying some WD40, or similar, in the gaps and leaving it for a while*.

(*I realise this is the bike equivalent to an IT help desk's 'have you turned it off and on again')

The caps are just held on by an o-ring so they slide off, but they're quite a tight fit. I usually use pliers or mole grips with something to protect the aluminium like a bit of inner tube or a rag. It looks like you've made quite a mess of yours TBH, but you might be able to straighten it out when you get it off.

you've laced it wrong.

The other side is laced right

^ i am unsure of the seriousness of this, and so feel quite silly explaining that my post was a joke at the whole incorrect-yet-correct crows feet lacing debacle espoused in this thread.

It doesn't matter on a fixed wheel, but on a wheel for a derailleur bike the drive side pulling spokes should be laced inbound because they get tighter under power and pull the third (outermost) crossing towards the centreline of the wheel. If you lace them as EFC has on the side facing us in the pic, the pulling spokes when using that side as the drive side will pull the crossing away from the centreline - this can potentially cause interference with the derailleur cage when applying high torque in bottom gear.

In short, I was joining in with your joke, because it really doesn't matter on a fixed wheel.