Bristol 411 , fractured wheel rim

[clewin]

Dear members,

I just had the terrible experience with a fractured wheel rim . Did any one have the same experience and a does anyone know, what could have caused the damage ?

[David C]

That looks really shocking! Must have been very scary when it let go.

It looks as though the cracks go through most of the mounting holes. I wonder whether the wheel nuts have been over tightened or under tightened at some stage. I imagine you will be getting the other wheels crack tested before you drive any further.

[Kevin H]

I'm sure I have read something before about fractures around the holes on the steel wheels of the 411, but it hadn't got anywhere near the shocking stage displayed in this thread. Nevertheless, this would have started with a small fracture or two.

[Barrie]

I suppose that bearing in mind we have little idea of what abuse our wheels have suffered over the last forty or fifty years we ought to have them xrayed at least once during our ownership. Here is one of the many facilities that carries out such work.

https://www.supremewheels.co.uk/how-we-do-it

From my personal experience I do know that cracks or crystallisation breakdown of the metal is not always visible with the naked eye although the outcome of my episode was nowhere near as serious as yours as it was limited to a single stud hole.

[David C]

It looks as though Magnaflux now do some DIY aerosols for crack testing that could be used for this.

SKL-WP2 penetrant and SKD-S2 developer. Roughly £20 per can each.

Does anyone have any experience of this sort of product?

[Roger Morrall]

clewin

I’m wondering whether your horrific pictures are indeed of a genuine 411 wheel.

I’ve noticed that the width of the web between the slots on your picture "fractured-wheel-rim-foto-reifen-2.jpg" appears to be narrower than the length of the slot.

When I compare your picture with one of a genuine 411 wheel (albeit one fitted to a 410 - attached) I perceive that the width of the web appears significantly wider than the slot. This is also my impression when I look at 411 wheels in Christopher Balfours excellent book "Bristol cars, a very British story". Now I know this is not germane to the bit that failed so catastrophically, but it causes me to wonder whether the wheel you picture might actually not be a Bristol wheel at all but might perhaps be a Jaguar wheel that has come to be fitted to your 411. I understand the Jaguar wheel looks very similar but is subtly different and I have heard of Jaguar wheels suffering the sort of failure you have had when they were fitted on Bristols.

Perhaps another 411 owner might be kind enough to measure and post the relevant slot & web dimensions to enable you to check out my suspicion that your wheel may not actually have been the genuine article.