Failing caliper lugs or spokes? I need some guidance!

[Mark Hooton]

Hi Guys(Gals), hope you are all ok in these strange times and riding safely

I never have the time to deal with anything that`s not directly in front of me so I`m after some (respected) views from anyone who can comment because I simply don`t know what the score is with this "collapsing wheel" business I have heard about, if there is one (don`t shoot the messenger!)?

Basically a fellow biker (who shall remain nameless until permission is given otherwise) has come to me stating that the `collapsing wheel` issue is NOT anything to do with the spokes, rather the real reason for the collapsing wheel is that the brake caliper lugs are failing, causing a catastophic chain of events resulting in wheel collapse.

Stressing I ALWAYS respect everybodys opinion, no matter what it might be however I then usually ask others (more knowledgable than me - its not hard ) for what they think before I make up my own mind.

The fellow biker has suggested that a bracket (made by me) which attaches to the ringed in red fastening points would a) greatly reduce the failure in the first place b) make me a billionaire and c) go viral. b & c I`ve heard too many times that I can remember and I still have to get up to go to work however before I dismiss it out of hand I thought I would ask you guys for your opinions?

Personally, I suspect the caliper lugs are just fine, with no design issues or reason for additonal support but what do I know! So, as an aside, has there been a loose spoke issue.......... (I don`t knw )

Thanks for your forbearance and any heads up and, please, ride safe and do nice things (buying me wine is in that category )!

And don`t forget, if I can help any of you then please say, I won`t forget the support I had off you guys all those months ago

[/url]idea by cymarceng, on Flickr[/IMG]

Ah, I already see that a good friend of mine has already put something out there!

https://www.ukgser.com/forums/showt...ar-wheel-collapse?highlight=collapsing+spokes

 

[Mark Hooton]

and thank you Giles - I guess you could be right here!


But there have been no reports of this happening with cast wheels! Its only happening with spoked wheels. So .. I don't agree

It aint the mount, its the spokes.

Blimey ..... look at all the dozens and dozens of people that have been affected by loose spokes in their wheel. Twizz on here had about 6 spokes that went thud when you twanged them.

It aint the calliper mounting bolts!! Its the wheel.

 

[Doc]

Is this on newer bikes ? Ie the 1250 ?

 

[spoonz]

I read a lot of the personal accounts of the failures and looked closely at the pics. Spokes and Calipers have obviously contacted but which failure started the chain reaction. I doubt the pictures or the rider could reliably make that call from the evidence.

The other point that makes me think it isn’t lugs is why are the failures almost exclusively with spoked wheels. If the lugs are a problem it should be across the board shouldn’t it ?

I have seen a technical bulletin regarding it from bmw but can’t remember exactly what it said. I’ll see if I can find it.

 

[beaver]

Has it ever been seen on cast wheels?... If its only spoked wheels then I guess thats a good indication

 

[Mark Hooton]

Hi Guys, thanks for the replies, I`ve actually just spent a lengthy time reading a thread started by Oldrat (hope you are ok pal) which I should have read in the first place and it seems that there`s all the information on the thread - I`m not a gambling man (neither time, sobriety or money) but my cash is on the spokes (so far).......

 

[spoonz]

This is the bulletin I mentioned. (Covers various models including the Gs) Seems to suggest re use of one of the bolts and over tightening after maintenance leads to potential failures.

BMW reports the following error pattern: “The material of the bearing journal, which connects the swing arm to the angular gear, is not of the correct quality. The necessary yield point is not reached. The error only occurs if the screw connection has been tightened manually in the reworking process.” Due to the error, the bearing pin can tear, which can loosen the screw connection of the rocker to the bevel gear. This can result in contact with the spokes on the rear wheel. In the worst case, there is a risk of falling. The bearing journal will be replaced on the affected vehicles.

 

[Mark Hooton]

This is the bulletin I mentioned. (Covers various models including the Gs) Seems to suggest re use of one of the bolts and over tightening after maintenance leads to potential failures.

BMW reports the following error pattern: “The material of the bearing journal, which connects the swing arm to the angular gear, is not of the correct quality. The necessary yield point is not reached. The error only occurs if the screw connection has been tightened manually in the reworking process.” Due to the error, the bearing pin can tear, which can loosen the screw connection of the rocker to the bevel gear. This can result in contact with the spokes on the rear wheel. In the worst case, there is a risk of falling. The bearing journal will be replaced on the affected vehicles.

"Angular gear" = FD?

 

[spoonz]

"Angular gear" = FD?

That was my assumption yes.

 

[Mark Hooton]

That was my assumption yes.

Yup mine too


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[Winjar]

This is the bulletin I mentioned. (Covers various models including the Gs) Seems to suggest re use of one of the bolts and over tightening after maintenance leads to potential failures.

BMW reports the following error pattern: “The material of the bearing journal, which connects the swing arm to the angular gear, is not of the correct quality. The necessary yield point is not reached. The error only occurs if the screw connection has been tightened manually in the reworking process.” Due to the error, the bearing pin can tear, which can loosen the screw connection of the rocker to the bevel gear. This can result in contact with the spokes on the rear wheel. In the worst case, there is a risk of falling. The bearing journal will be replaced on the affected vehicles.

I believe that was for latest bikes, not older ones that failed, bracket to secure caliper more look very interesting, offroad heavy load, I would like one please.

https://motorcycles.news/en/recall-of-various-bmw-models/

 

[spoonz]

I believe that was for latest bikes, not older ones that failed, bracket to secure caliper more look very interesting, offroad heavy load, I would like one please.

https://motorcycles.news/en/recall-of-various-bmw-models/

It may be a red herring but the wheel failure part caught my eye.

The recall is for later bikes having a specific problem with the material used not having enough margin for over stress. But that doesn’t mean a random % of earlier bikes aren’t suffering failures from over torqued bolts in a similar fashion. Like anything there is a failure point If stressed, especially repeatedly over a few years. How many bikes that have had diy spline maintenance have had their bolts tightened without a torque wrench for instance.

The other thing I noticed about some of the failure bikes was that they were carrying significant luggage, not just the usual panniers so load may be a factor. I still think spoke failure is the Most likely trigger in most cases.

 

[Winjar]

It may be a red herring but the wheel failure part caught my eye.

The recall is for later bikes having a specific problem with the material used not having enough margin for over stress. But that doesn’t mean a random % of earlier bikes aren’t suffering failures from over torqued bolts in a similar fashion. Like anything there is a failure point If stressed, especially repeatedly over a few years. How many bikes that have had diy spline maintenance have had their bolts tightened without a torque wrench for instance.

The other thing I noticed about some of the failure bikes was that they were carrying significant luggage, not just the usual panniers so load may be a factor. I still think spoke failure is the Most likely trigger in most cases.

All is very possible, and I can agree, it is possible we only hear about spokes because it finish very bad, I wonder if rear break caliper has broken or come loose on other bikes also without spokes, look below.

https://advrider.com/f/threads/2012-r1200-gs-adv-rear-brake-caliper-fell-off.1091525/

https://advrider.com/f/threads/rear-brake-collapse-disaster-pics-and-questions.969129/

 

[Winjar]

I just see also BMW make service bulletin in 2017 and say use 5mm longer bolts.

https://www.realoem.com/bmw/enUS/sh...0-BMW-R_1200_GS_17_0A51,_0A61_&diagId=34_2072

 

[twizzle]

To be honest Mark from a personal litigation perspective I’d not try and fix this - assuming your “hard” part is fitted and a failure still happens - it weakens a case against the manufacturer - opens a door of doubt around cause and effect and drags you into a muddy exercise - if a rider dies or is seriously injured .... well if I were you I’d not want to be involved.

In 2018 a batch of dodgy wheels made it through - loose spokes were common and lots of wheels replaced including mine.

I’d stay away from this one.

 

[dean0n0]

Before I got to Twizs answer I was thinking the same.

 

[Mark Hooton]

To be honest Mark from a personal litigation perspective I’d not try and fix this - assuming your “hard” part is fitted and a failure still happens - it weakens a case against the manufacturer - opens a door of doubt around cause and effect and drags you into a muddy exercise - if a rider dies or is seriously injured .... well if I were you I’d not want to be involved.

In 2018 a batch of dodgy wheels made it through - loose spokes were common and lots of wheels replaced including mine.

I’d stay away from this one.

Funnily enough the hairs were standing up on my neck over this - I’d rather be part of the solution than part of the problem however when it comes to legalities I suspect both BMW and the vultures wouldn’t hesitate to deflect blame, knowing I lack the resources to fight any claim.


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[JohnnyBoxer]

To be honest Mark from a personal litigation perspective I’d not try and fix this - assuming your “hard” part is fitted and a failure still happens - it weakens a case against the manufacturer - opens a door of doubt around cause and effect and drags you into a muddy exercise - if a rider dies or is seriously injured .... well if I were you I’d not want to be involved.

In 2018 a batch of dodgy wheels made it through - loose spokes were common and lots of wheels replaced including mine.

I’d stay away from this one.

Bang on

Walk away from the laser cutter

 

[spoonz]

I would agree re the litigation etc but it would would be nice if a failure point was identified. It’s not tied to the 2018 wheel issues directly as some of the failures were pre 18 bikes.

 

[Winjar]

I would agree re the litigation etc but it would would be nice if a failure point was identified. It’s not tied to the 2018 wheel issues directly as some of the failures were pre 18 bikes.

Maybe combination of both, bad spoke make wheel not round and make disc shake a little and make caliper fall out, and caliper go into spoke and destroy rear wheel, this not happen on cast because wheel runs straight, so BMW make longer bolt and better spoke.