BearBack – I’d presume that the reason Russ didn’t go after the QR manufacturer is because in effect they don’t exist any more. The Syncros that designed/made Russ’s QR had gone belly up and GT bought the name for their OEM stuff, since then the name has changed hands again and is part of the same group as Ritchey.
As an aside the QR design was so old that I’m pretty sure that when it was designed and manufactured disc brake use was not prominent so it could easily be argued that it was never designed to be used in conjunction with a disc brake.

aracer – If Russ believes what was claimed in court to be correct then he also believes that the sequence of events that led to his accident WILL happen again to somebody else. His claim was not that a use of this qr, with this brake on this fork is dangerous but was in fact ALL forks with vertical dropouts and disc mounts are dangerous and wheels WILL be ejected from the dropouts regardless of which qr, hub or brake you use on a fork with vertical dropouts.
Now of course I can sympathise with his situation, I can’t even begin to imagine how horrendous paralysis must be. Yet by taking the out of court settlement he has missed the chance to stop what happened to him potentially happening to THOUSANDS of other people if what he believes to be true is just that.

To be honest though I don’t believe that vertical dropouts are to blame for his accident I think using an ancient, stretchy, knackered qr is the more likely culprit but as I said at the top of this post chasing them for money was never going to be viable.

On a more general ‘product liability’ note – how does buying a complete bike compare with a home build ?
If you buy ‘ready to ride’ then the manufacturer has selected components that in their view are performance and safety matched and the retailer will have used their profrssional epertise to assmble them.
If you self build I assume you take responsibility for the combination of parts you have selected and so lose any claim for liability if they don’t work together ?? (unless of course they don’t individually conform to ISO standards or there are material defects)

Yet by taking the out of court settlement he has missed the chance to stop what happened to him potentially happening to THOUSANDS of other people if what he believes to be true is just that.

But why is that his responsibility more than anybody else’s – particularly those who believe in the theory as it seems you do (otherwise why is it an issue to you at all)? Hence you are just as culpable as him – if you were really bothered you could have always contacted him and provided him with sufficient funding to take it all the way.

To be honest though I don’t believe that vertical dropouts are to blame for his accident I think using an ancient, stretchy, knackered qr is the more likely culprit

With appropriately aligned dropouts it wouldn’t happen even with the stretchiest skewer, so why is the skewer to blame? In reality I’d suggest it’s a combination of factors, but the fork manufacturers who were aware of the issue are far from blameless.

aracer – I’m sure Russ and his legal team considered asking for donations as it is quite common for plaintiffs to make appeals for ‘fighting funds’ for cases when the outcome will be of benefit to interested third parties. I’m sure if Russ had put such an appeal on here and similar forums then he would have got plenty of support. A problem with that sort of appeal though would be that he would then be obliged to follow the case all the way through and would have to forgo a significant out of court settlement.
By not following the case through to a conclusion it seems apparent that the reason that this case was taken to court was simply to obtain compensation, where there is blame there’s claim, and all that.
Now there is nothing wrong with him doing that, I’d probably do the same myself if I was in his situation. What I wouldn’t want though would be my mates implying that I’m some sort of a saint fighting the big company for the sake of the common mountain biker.

As for your second point ‘why is the skewer to blame?’. If you don’t believe the performance of a skewer on a bike plays by far the most significant role in maintaining the wheel between the dropouts then it’s pointless discussing this with you. Even a child would be able to identify that a skewer is what keeps a wheel within the dropouts regardless of the orientation of the dropout.

Jim – you soooooooooooooooooo miss the point. With a downward facing dropout a QR failure will be catastrophic as the wheel will be ejected. With a forward facing dropout out it wont. Fail safe????

When there is a clear mechanism for QRS undoing and a QR was never designed for these stresses then QRs will fail ( rarely but I know of half a dozen cases}

With a downward facing dropout a QR failure will be catastrophic as the wheel will be ejected. With a forward facing dropout out it wont. Fail safe????

I would be unhappy riding a disc braked bike without a skewer, particularly over a rough undulating surface.

I have ridden a Magura braked bike with a completely loosened skewer, and surived a small jump without worry. The calipers rubbed the tyre and stopped the wheel falling out.

With a disc braked bike, there is no such backup.

TandemJeremy – After reading some of the reports Anaan, etc, I have come to the same conclusion as you that the forces necessary to loosen the quick release are present. Also that should the quick release be loose and thus no friction between the dropout and the hub during braking then the wheel will eject from a fork with vertical dropouts. This I’m sure is one of the reasons that ‘Lawyers Tabs’ were fitted as a fail safe.

What I don’t believe is that if a functioning qr is fitted correctly that under braking it is able to stretch/deform enough to not only become loose but to also clear the layers tabs with out even marking them. I just don’t see how Russ’s accident could have happened without either user error or a malfunctioning quick release being the most significant factors.

I’m puzzled about this – the braking forces managed to rip the qr clear of the lawyer tabs? Did the qr itself break or was it pulled free?

And over what sort of timeframe/distance are we talking here? From memory the worst section of the Gap ride is over fairly quickly. We are talking about 100s of yards rather than Alpine miles, iirc. Is that a factor, in that the damage was done over time, or did it happen instantaneously?

I’m not taking sides, just puzzled that something like that could happen to an experienced rider without him being aware that something was wrong.

I would be unhappy riding a disc braked bike without a skewer, particularly over a rough undulating surface.

Yep – me too. With no skewer at all, all bets are off, as a variety of forces from bumps could push the wheel out, whatever direction the dropouts faced. The point though is that with downward facing dropouts, braking WILL force the wheel straight out, whereas if you change the alignment it won’t. Therefore a skewer which will withstand normal forces will withstand braking forces if you align the dropouts correctly, even if it only just withstands normal forces.

It’s pretty easy to not tighten up a QR lever enough, particularly if there’s grit or mud in the mechanism. There’s a well written article by Sheldon about this here:

http://www.sheldonbrown.com/skewers.html

So I’d really take the “half a dozen of my friends had QR levers loosen” stories with a pinch of salt. If there’s any issue to be aware of, it’s keeping your QRs clean. Spending £400 on a new set of forks won’t help you much if you don’t maintain them properly. I’ve had the Maxle on my Pikes come loose because it was gunged up, and seen pictures of broken dropouts on 20mm forks that were overtightened.

The point though is that with downward facing dropouts, braking WILL force the wheel straight out, whereas if you change the alignment it won’t.

But will it? Given the geometry of many fork legs / caliper placements, braking will force the axle back as well as downwards, towards the back of the dropout, rather than directly down.

The calculations of Annan et al assume that the interface between the caliper and disc acts as a pivot point. If this effect occurs, then in many fork leg/caliper configurations the axle could not come out of the drop out.

If there is displacement of the axle in the dropout then this is different to the rotational movement originating from a pivot, but it is the interaction between pad and disc rotor that would have to originate any such displacement. I’m no expert, but from a layman pespective I’m not sure that I see how a displacement occurs that is sufficient in magnitude to overcome the pad/rotor interaction that originated the forces that Annan describes as being in the direction of the dropout opening.

Once you add in the skewer/axle/dropout interaction as well (that is present under normal conditions) I just don’t see where this huge ejection force is coming from in many (most?) fork/disc/caliper combinations.

Testing this in the ‘bike upside down with the skewer undone’ garage laboratory the wheel does not eject under braking. The axle may bang/rattle in the dropout, but the combination of dropout/disc/caliper geometry and the effect of the brake restricting the movement of the wheel restrains the axle in the dropout

I’m still open to the idea that I’m missing something in this pure ‘forces’ argument (as distinct from the loosening-skewer argument), but no-one has put one forward as yet.

seen pictures of broken dropouts on 20mm forks that were overtightened.

Fox 36’s by any chance?

seems to be a theme here.

Rich, I think those particular ones were a 36, but why is that a theme? Bloke riding QR forks has an accident, he’s horribly injured, no-one knows for sure how or why, it goes to court, lots of handwringing on forums. Bloke’s 36s fail, sends them back, they say he’s overtightened them, they warranty them anyway (IIRC).

36’s are the only forks that I’ve heard of which had a problem with snapping dropouts from over tightened bolts and the torque for the bolts was very low, so it was very easy to do (and who carries a torque wrench on rides with them?).

Every other manufacturer seems to have put enough metal in so that this doesn’t happen. Hence the theme seems to be Fox not putting enough engineering thought into their designs.

Also I though most of the snapped dropouts on 36’s got refused warranty? due to *user error* and the next years models came with a washer to ensure the dropouts couldn’t be squashed together enough to crack them.

And over what sort of timeframe/distance are we talking here? From memory the worst section of the Gap ride is over fairly quickly. We are talking about 100s of yards rather than Alpine miles, iirc. Is that a factor, in that the damage was done over time, or did it happen instantaneously?

The accident happened way down near the bottom of the trail, where it’s not too steep or rocky, and really open. So he must’ve been really pinning it, as far as I can tell.

But will it? Given the geometry of many fork legs / caliper placements, braking will force the axle back as well as downwards, towards the back of the dropout, rather than directly down.

M – I thought this when I heard about it in the first place and the arguments were going on then. So I undid my skewer and rode slowly round the carpark and tapped the brake. I theorised that the forward force of my weight under braking would keep the wheel in the dropout. Well, it didn’t. A tiny tap of the brake pulled the wheel out of the dropout on the disc side. If I’d properly braked, it’d have twisted the wheel and mangled the disc. At speed, this would have bent the disc to buggery, ripped the caliper off and certainly dumped me on my face.

If I’d been going slowly down something very steep, it might’ve been different (but I’m not prepared to do this experiment). So the fact that it was at the bottom of the Gap where the trail’s not steep but very fast is probably a contributing factor. There are also not that many trails like that (relatively speaking, compared to what most people ride regularly) so one would conclude that a lot of people whose skewers come undone wouldn’t have the same problems as Russ.

Given the geometry of many fork legs / caliper placements, braking will force the axle back as well as downwards, towards the back of the dropout, rather than directly down.

The dropout then constrains the motion of the axle to a downwards direction like the keel on a sailing boat. Since there is a component of force in the downwards direction that’s the way it goes – the only way to get rid of this component is to align the dropouts so they are perpendicular to the original force (alignment so the force pushes the axle into the dropout would also be acceptable). Personally I’d still prefer a lightweight QR through axle system which doesn’t have this problem at all though. Unfortunately no lightweight race forks such as I use yet come with such a feature – though by my calcs it could be made just as light and with faster release than having to unwind a skewer to get past tabs.

Every other manufacturer seems to have put enough metal in so that this doesn’t happen. Hence the theme seems to be Fox not putting enough engineering thought into their designs.

You seem to be assuming that Russ’s accident was the result of the forks he was using, and not the QR or the way the wheel was installed. Nothing proved there. And as for Fox having shoddy engineering, Marzocchi QR20 anyone? The fiddliest and most fragile system for installing 20mm forks known to man? Or the broken Revs that the bloke posted further up the thread? (Even though he broke them by doing stair drops to flat.) If you’re going to be paranoid, at least be fair.

Unfortunately no lightweight race forks such as I use yet come with such a feature – though by my calcs it could be made just as light and with faster release than having to unwind a skewer to get past tabs

I’m looking for old-skool Control Tech style skewers for my race bike. In the belief that this might be better…..

Been following this a bit and having read the blog and James Annans pages there’s a few things that stand out from the trial reports.

In October 2005 Fox submitted a patent application in the names of two of their designers (one of whom was in the witness box as the paper was disclosed). The patent application was for a “new design of dropout”; specifically one that had a forward facing angle relative to the fork lower of 40 degrees. As part of the application commentary was the phrase “massive forces through the centre of the disk brake pad”. These forces, the maximum recorded in a document published by Hayes the brake manufacturers in 1999, were around 4,430 newtons, represented simultaneously a force in the order of 3-4,000 newtons on the axle at the disk brake side drop out. Reading from the patent application the plaintiff’s counsel asserted that the patent application design change was “specifically to prevent ejection of the wheel under braking forces”.

So it appears fox made a patent application for their revised dropouts and the stated reason for the redesign (and thus the patent application) was “specifically to prevent ejection of the wheel under braking forces”.

If the wheel can’t be ejected under braking why did Fox make this Patent Application stating that as the (a?) reason?

As to the question of riding along with a loose QR it’s already been said about the nature of the Gap track – perhaps the following from the court blog is of relevance –

have summarised all the agreed technical evidence with respect to Quick Release behaviour……. 6) Loose screwing nuts CAN UNWIND VERY QUICKLY THROUGH VIBRATION

The obvious cause you would have thought would be a crap or incorrrectly installed QR and that can’t have missed the attention of Fox’s legal bods, had the QR not complied with the relevant standards for QR’s then the case would surely never had got off the ground let alone made it to court. If it was incorrectly installed then having ridden the route, he made it a long way round without noticing before the wheel came out.

I was also more than a little concerned with the statement

These forces, the maximum recorded in a document published by Hayes the brake manufacturers in 1999, were around 4,430 newtons, represented simultaneously a force in the order of 3-4,000 newtons on the axle at the disk brake side drop out.

This figure is twice that calculated by James Annan and three times the force he says the standards require to be resisted by the QR. Presumably the fact that this document was brought up in court suggests either that Fox had that document or that they should have done similar testing to establish the forces involved?

Still the running theme from the court reports seems to be that

whilst the theoretical sequence could be defined it was only in a combination of many complex factors (many of which he believed were either not able to be identified yet, or if they are not adequately explained) acting in exactly the right manner that the very unfortunate sequence could occur in real life.

which will be of no comfort to Pinder but will hopefully mean that, as molgrips explains above, the chances of another serious injury happening even if (or when?) the next wheel gets ejected are low.

Seems there’s a lot of smoke there if there’s no fire but as people have said it’s a shame that we’ll not get a definitive precedent setting ruling. The cynical amongst us might conclude that it’s in the interests of the manufacturers that we do not.

Wunundred!

Well put spannerman. there is also the question of precessional forces unscrewing the QR even from tight – then once its loosened a bit the vibration might do the rest.

As you say its a shame no definite conclusions were reached and cynical me absolutely agrees with your last sentence – if a precedent had been set how many people would be suing?

Is there a “Standard” for QRs?

Can i sue them for the worry and anxiety this is causing me?

Can we lay this one to rest now please? Even if there had been an award of damages by the Court it’s clear that QR forks with the wheel properly installed are far from unsafe. I rode the same route myself (just after I got some QR Fox forks in fact) and didn’t die, nor do hundreds of other mountain bikers who do that route (or even rougher ones) each year.

I don’t think it’s idle speculation to suggest that even if he was successful Russ’s award could have been reduced massively due to contributory negligence. So it might have lead anyone looking to bring a similar claim to reconsider. And if there had been a ruling against the fork manufacturers it wouldn’t necessarily work against them – loads of people are already rushing to buy massively expensive XC forks with non-QR retention systems, and presumably if they have the strength of TJ’s convictions they’ll be throwing the old ones in the bin rather than selling them on.

I don’t run QRS and disc. both disc brake bikes have 20mm axles.

spannerman – your analysis of the key points of my reports I think is spot on and has managed to avoid the many red herrings that seem to have distracted a lot of the other commentators on this thread.

Neither side was able to conclusively model, measure or recreate the sequence of forces wholly BECAUSE it is such a complex and dynamic interplay of all the components, user actions, and environment.

I believe a crap QR may well bear some responsibility for the accident, but the fork design was such that EVEN IF THE QR was done up correctly, it could have led to the ejection of the wheel. But even then, my opinion is, as you also suggest, that the correct sequence of events is so remote that it would be a very rare occurence.

Stoner (aka spoompliM)

I don’t think it’s idle speculation to suggest that even if he was successful Russ’s award could have been reduced massively due to contributory negligence.

Mr A there would never have been a reduction since the case was not brought for negligence. The case was brought under the consumer protection act.

Even with a 20mm axle you can still have a failure caused by bad installation.

Stoner, surely it’s still a PI claim though?

Mr Agreeable – true. But with a QR you can have a failure even with correct installation.

Even if there had been an award of damages by the Court it’s clear that QR forks with the wheel properly installed are far from unsafe. I rode the same route myself (just after I got some QR Fox forks in fact) and didn’t die, nor do hundreds of other mountain bikers who do that route (or even rougher ones) each year.

All your evidence proves is that the vast majority of the time the conditions which make such a combination unsafe don’t happen. It proves absolutely nothing about whether there is an inherent issue.

I’m not sure though why people are getting so hung up on the idea of a judgement being so important. I can see 3 reasons behind this:
1) You want to know whether you should keep using your QR disc forks.
2) You want to sue because you’ve had a crash.
3) You want all QR disc forks to be recalled.
4) Have I missed another reason?

To which I respond:
1) Do you really trust lawyers over engineers on a safety critical issue relating to your riding? All the engineering arguments are out there for you to read already.
2) Go ahead and sue if you have the evidence. This isn’t the first out of court settlement of a disc brake related front wheel ejection. If you have the right evidence and argue it the right way, the chances are you’ll win (in or out of court).
3) Fair enough – though I doubt a judgement would have resulted in a general recall.

But with a QR you can have a failure even with correct installation.

Or your steerer tube could snap. Or your brakes could stop pack in. Or your tyres could burst. Or your wheels could disintegrate. Really, I’m surprised any of us leave the house…

Did anyone actually ever find a link to this patent? I’ve had a look several times but nothing ever seems to match…

funkynick – I did look hard for it but could never find it. It was confirmed to me in the courtroom that it was never granted but that the application was “in the public domain”. I even had the benefit of the name of the designer as applicant but still had no luck. That was why I referred to the catalogue for 06 instead.

36’s are the only forks that I’ve heard of which had a problem with snapping dropouts from over tightened bolts and the torque for the bolts was very low, so it was very easy to do (and who carries a torque wrench on rides with them?).

Sadly not.. Marz 888’s went through a phase of breaking the through axle tabs from over tightening.. Fox and IIRC Marz have warning stickers to inform you not to over tighten the pinch bolts..
Of 3 second hand 888’s on complete bikes I’ve had, 2 have been snapped here.. fortunately they also snapped mid lower casting at the mid bushing machining so I got both lowers warranty replaced.

With a downward facing dropout a QR failure will be catastrophic as the wheel will be ejected. With a forward facing dropout out it wont. Fail safe????

Without real world testing, I expect there a very high probability that a failed QR on a forward facing drop out fork would also cause the wheel to fall out (if you continue to ride) I appreciate that if you immediately [as quickly as this catastrophic failure occurs] identify the QR failure and continuously apply brakes till you stop, said wheel may stay in place.
So, ultimately, direction of the dropouts aside, a failed QR is still a failed QR 🙁