China – Toro Rosso upright failure

As you can see, the upright failed towards the top mounting (top right in this picture) where the top wishbone and steering arm connect.

In Free practice to day, Toro Rosso suffered a massive front suspension failure.  The team have put this down to the failure of the upright.  An upright is the component that links the suspension wishbones to the axle and the wheel.  It appears the upright was new and from a batch not previously used.  Its not clear if the upright was a new specification or a newly manufactured batch of the existing spec.

Due the multitude of functions the upright has to accommodate, it is subject to enormous stress.  This is particularly found under braking as the upright has both the load from downforce, braking and suspension movement.  An upright is joined to the suspension at three places; the upper wishbone mounts via a spherical bearing\camber plate bolted to the top of the upright, the steering arm via a spherical joint\clevice bolted to the uprights front edge and the lower wishbone normally attached with a spherical joint bolted directly to the bottom of the upright.  Then the brake caliper bolts to the upright in two places, lastly the axle (hub) rotates in two large diameter bearings through the middle of the upright.

A typical old format upright in cast titanium, featuring a vaned bearing holder

Uprights were commonly made from titanium or MMC up until this year, when the rules were changed to demand aluminium.  The BBC TV sports broadcast wrongly suggested they were made from carbon fibre, No Carbon upright has raced in F1.  The metal upright is cast\machined, rather than the previous practice of welding various parts together, this is due to the different layout of the modern F1 upright, which no longer places the hub in relatively small bearings inside a vaned mounting to pass cooling air to the brakes.  Instead the bearings are larger and the upright wrapped more tightly around the hub, the cooling air now passing around the upright via the carbon fibre brake duct.  Only BAR\Honda had a different solution, which routed the cooling air inside an oversized hub to the brake disc.  This set up compromised the packaging for the Brawn BGP001, leading to its relatively low nose.  For 2010 Mercedes (nee Brawn) have more conventional uprights.

a BAR Honda Upright (exploded), with the large diameter hollow hub visible that feeds cooling air to the brake

In Toro Rossos case the point at which the upright failed is yet to be confirmed, if it will be made public at all.    Most likely the point at which suspension loads pass into the upright will be the area of highest stress and likely to cause the type of catastrophic failure we saw in Shanghai.  Thus the failure could equally be attributed the wishbone ends or the camber plate, rather than the aluminium upright itself.

18 thoughts on “China – Toro Rosso upright failure

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  2. Seriously … Your blog should be required reading for anybody who want to understand Formula 1 racing.

    Brilliant stuff! Thanks!

  3. Thanks for the useful info! It was interesting to see what was presumably the left upright fail within milliseconds of the first one – I know it’s early days but would that indicate a common structural weakness or would there just be unusually massive forces acting on it once the opposite one goes?

    • I am fairly sure that as soon as one goes the other will not be capable of taking the strain, but I’m sure you will be provided with an explanation from the expert! In fact I dont quite understand that explanation because the load transfer cannot be put all onto the other side, surely the braking and downforce loads would just cause the first side of the car to hit the ground, rather than go onto the other side…I have confused myself!

      Scarbs I agree your blog is fantastic! I can only ask for more! I would be interested to know if the parts are machined or cast, I always assumed that machined parts were stronger and able to produce a greater level of accuracy? but maybe with modern casting and hydro-forming methods…not my area of expertise!

      • STR themelves said that the right side failed due the added load from the left upright failure. I expect the second failure was not a upright breakage but the suspension failing, I will ask STR and see if we can get some official comment.
        Casting is popular, Esp when titatnium was used. But now with ALu and as most surfaces are machined at some stage its hard to tell…

  4. Thanks again for a seriously entertaining and most importantly *factual* insight to the issue at hand in F1. And thanks for being observant enough to recognise when others make mistakes, and point out those mistakes! BBC F1 has been very enjoyable – especially the lack of ad-breaks (thanks Trust Board) – but for in depth analysis your pieces take the biscuit.

  5. It was really awkward to see it happening almost simultaneously on both uprights. Could it happen due to a brake failure?

    By the way, congratulations on the blog!

  6. I saw this video on the BBC website, and was like geeez how did that happen?? I know where I can find out…. ScarbsF1.

    Great blog Scarbs, I have been an F1 fan for some time, but only this season have I taken a real intertest in the technical side of it. This site gives me everything, hardcore technical stuff which I can more or less understand.

    I take my hat off to you sir, keep it up!

  7. If these modern aluminum uprights are CNC (Computer – Numerically Controlled) machined from a one-piece block of metal – or “billet” – that alone can introduce massive stress points that working with a casting – whose “grain” normalises in the casting and post-casting treatment “baths” virtually eliminates. Forging – not normally used in aluminum fabrication – is one of THE strongest methods of first-stage forming of high-stress components. Almost ALL engine crankshafts begin life as “forgings” – as do the crank-to-piston “connecting rods”. Next would come casting – aluminum is prime for this first-stage forming method with post-casting annealing baths (e.g.) to relieve cast-in stresses – and finally – for a high-stress piece, the last way I’d consider as a mfg process would be CNC machined from a single uni-block of metal. Especially in aluminum! Stress-relieving baths *CAN* help reduce stress points and help provide for a smoothing of the internal “grain” of metals such as aluminum … but it can never eliminate them.

  8. Given an apparent failure of 1 upright and the subsequent near instant failure of the 2nd is it safe to say the 2nd failure was due to vertical load?

    My thinking, as a lay-man, is that the horizontal retardation would have been halved with the loss of the left brakes so the only additional load on the right upright was vertical load?

    That’s not to say there’s anything wrong or unexpected about this. Parts in F1 must be so pared-down to absolute minimums that designing something for twice it’s expected load would add unnecessary weight?

    I’m new to the technical side too and only discovered your blog a week before Australia so I’m still learning!

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  10. I first read your blog right after Australia’s race this year. Today when I saw the video of the accident, I knew where I had to look for an explanation. Your blog is great! I hope you manage to keep it going and make a well deserved living out of it, either directly or indirectly (bringing more business to you).

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