Final drive rebuild

[Bendy toy]

The FD is tied back to the frame with a parallel bar.

The shock stops the swing arm going up or down too far.

The Motorrad tester didnt find any problems with his test ride (presumably after the shunt) so how can he say the UJ failure was caused by the accident?

 

[autogs]

top link works in expansion and contraction

 

[Mr Bean]

Thanks both.

My question is:

Is it possible for the rear impact (30mph when stationary) to cause damage to the shaft or bearings in the UJ by the final drive pivoting forward?

I appreciate under normal usage this would not be an issue.

 

[autogs]

anything is possible,a sharp shock to the uj may have accelerated a break up of the joint but lets get real proving it would be impossible.

 

[Mr Bean]

Thanks.

According to the legal advice the issue is either an insurance issue or BMW's.

Apparently, even though the BMW extended warranty expired in March if there was a 'latent' issue that no one was aware of then BMW are probably still liable for the repair costs.

 

[jwpzx9r]

Thanks both.

My question is:

Is it possible for the rear impact (30mph when stationary) to cause damage to the shaft or bearings in the UJ by the final drive pivoting forward?

I appreciate under normal usage this would not be an issue.

At the risk of causing you an offence, are you certain of the impact speed? The reason I ask is that is a high speed for a stationary vehicle to be hit without suffering some major damage. At that rate of impact I personally would expect broken wheels and buckled frame minimum. Lets be honest a car hitting you from the rear at 30 mph is going to travel right through you before coming to a halt, both you and the car are going to travel quite a distance, a car under braking from thirty mph travels more than 10 meters and you would not have greatly reduced that distance since you have not sustained sufficient damage to have absorbed the energy of the impact. Sorry but I think you have over estimated the speed at which the vehicle that hit you was travelling. Remember momentum is conserved in an impact so where did the energy go... you have very little damage. Out of interest what damage did the car suffer?

 

[Mr Bean]

At the risk of causing you an offence, are you certain of the impact speed? The reason I ask is that is a high speed for a stationary vehicle to be hit without suffering some major damage. At that rate of impact I personally would expect broken wheels and buckled frame minimum. Lets be honest a car hitting you from the rear at 30 mph is going to travel right through you before coming to a halt, both you and the car are going to travel quite a distance, a car under braking from thirty mph travels more than 10 meters and you would not have greatly reduced that distance since you have not sustained sufficient damage to have absorbed the energy of the impact. Sorry but I think you have over estimated the speed at which the vehicle that hit you was travelling. Remember momentum is conserved in an impact so where did the energy go... you have very little damage. Out of interest what damage did the car suffer?

Don't worry about offence - I offend daily!

I am quoting what the driver said - all I know was I heard a screech and was punted in to the van in front. At the time of impact I was stationary, probably two meters behind the van in front.

The wheel and tyre were replaced as part of the repair, one of the footrest hangers was bent too.

The VW Polo van that hit us was caved in with a nice V in the front.

After being hit we were punted in to the van in front at an oblique angle. With sufficient impact to cause the articular surface in my radius to be shattered in to around 8 pcs.

 

[jwpzx9r]

Don't worry about offence - I offend daily!

I am quoting what the driver said - all I know was I heard a screech and was punted in to the van in front. At the time of impact I was stationary, probably two meters behind the van in front.

The wheel and tyre were replaced as part of the repair, one of the footrest hangers was bent too.

The VW Polo van that hit us was caved in with a nice V in the front.

After being hit we were punted in to the van in front at an oblique angle. With sufficient impact to cause the articular surface in my radius to be shattered in to around 8 pcs.

I again doubt the speed involved. It could be that the driver of the van that hit plucked the figure from the air, but let's look at the facts that we know. You heard a screech, I presume of the vans tyres under braking, which if I am looking at things correctly means that the the vans brakes were locked prior to the impact. That could mean one of two things. The van driver was doing thirty mph braked locked his brakes in an effort to stop and hit you at a speed well below thirty mph or the van was still travelling at thirty mph with locked wheels when he hit you. If the latter really was the case then your bike would have been well crushed between the van that hit and the stationary van in front because you would have had to absorb the energy of the impact and two meters would not be far enough to slow that impact enough to avoid stop that van crushing the bike between it and the van in front. At thirty mph the van that hit you would not stop on impact it would travel quite a distance after the impact and since that van in front had to be stationary I just don't think you were hit by a thirty mph impact. The main thing is that you were not seriously injured but the fact remains and this is purely my opinion if you had been hit at thirty mph from behind while stationary with another stationary vehicle only two meters in front of you I would be amazed if there was not A) major damage to your bike and B) major injury to you due to the impact.

 

[Mr Bean]

I again doubt the speed involved. It could be that the driver of the van that hit plucked the figure from the air, but let's look at the facts that we know. You heard a screech, I presume of the vans brakes, which if I am looking at things correctly means that the the vans brakes were locked prior to the impact. That could mean one of two things. The van driver was doing thirty mph braked locked his brakes in an effort to stop and hit you at a speed well below thirty mph or the van was still travelling at thirty mph with locked wheels when he hit you. If the latter really was the case then your bike would have been well crushed between the van that hit and the stationary van in front because you would have had to absorb the energy of the impact and two meters would not be far enough to slow that impact enough to avoid stop that van crushing the bike between it and the van in front. At thirty mph the van that hit you would not stop on impact it would travel quite a distance after the impact and since that van in front had to be stationary I just don't think you were hit by a thirty mph impact. The main thing is that you were not seriously injured but the fact remains and this is purely my opinion if you had been hit at thirty mph from behind while stationary with another stationary vehicle only two meters in front of you I would be amazed if there was not A) major damage to your bike and B) major injury to you due to the impact.

I cannot quote with any degree of certainty, but we were travelling on a winding A road (national speed limit) in Sussex when we came round a bend to find a Transit van stopped in the road. I stopped quickly - not sufficient for the wife to headbut me. We were about two meters from the Transit (stationary) when we were punted in to the nearside corner - the only real impact with the Transit was with the plastics/bars/my wrist. We were midway alongside the van with the bike on my wife's leg.

The driver that hit us was certainly not paying attention to what was happening and was sent on an awareness course by Sussex police.

As mentioned previously we hit the Transit at an oblique angle which is why the bike was not crushed - only my wrist.

The initial repair quote to the insurers (I know it went higher) was £4,600 +VAT. I am also likely to require further surgery to fuse the bones in the "radio carpal" joint - in effect lose my wrist function. As it is, I only have 50% today. As an aside, try wiping your backside without flexing your wrist!

Apart from the wheel, tyre and footrest hangers (all with reported damage) the only other thing that I suspect could have been damaged is the swing arm/final drive - hence my question:

"Is it possible for the rear impact (30mph when stationary) to cause damage to the shaft or bearings in the UJ by the final drive pivoting forward?"

 

[Bendy toy]

A 30mph impact between transit back end and car front end would probably have killed you TBH. The bike would have been toast.

The driver probably claimed to have been doing 30 when he hit the brakes. If the speed limit was 30, to say anything else would invite a more serious charge from the police. The final impact speed is unknown but hardly matters. The car suffered frontal damage and presumably the vehicle in front of you suffered damage.

With something as complex as a BMW Boxer back end, its not unreasonable for hidden faults to surface when the bike superficially looks ok. Its not designed to take loads like that. The bike back end suffered various damaged parts so nobody can say the UJ drive-shaft and FD failures were not caused by the crash. What about the swing arm bearings, frame, gearbox, forks, front wheel, etc? All should (have been) be inspected and replaced if needed. If this was not done properly by the accident garage then they may need to sort it out. Hopefully the insurance will deal with it.

I think you have more than enough grounds to claim on the offending party's insurance. The final impact speed is really not relevant as there is more than enough evidence from the damaged suffered to the vehicles involved.

That arm wont be playing tennis again. This is definitely a personal injury claim get every penny you can! AND work VERY hard on the physio one to one if possible. Fusing the joint is an absolute last resort.

 

[Mr Bean]

The driver probably claimed to have been doing 30 when he hit the brakes. To say anything else is inviting a more serious charge from the police. The final impact speed is unknown but hardly matters. The car suffered frontal damage and presumably the vehicle in front of you suffered damage.

With something as complex as a BMW Boxer back end, its not unreasonable for hidden faults to surface when the bike superficially looks ok. What about the swing arm bearings frame, forks, etc? The bike back end suffered various damaged parts so nobody can say the UJ driveshaft and FD failures were not caused by the crash. All should be inspected and replaced if needed.

I think you have more than enough grounds to claim on the offending party's insurance. The final impact speed is really not relevant as there is more than enough evidence from the damaged suffered to the vehicles involved.

Your arm was badly broken - a comminuted fracture of the radial head is really not good news. That arm wont be playing tennis again. This is definitely a personal injury claim get every penny you can! And what about the wrist and shoulder? Soft tissue damage can be just as debilitating as a bone fracture(s).

You responded before my reply but you are correct I have a comminuted fracture of the radial carpal joint and it is a problem. I can no longer unscrew tightly closed jars, have difficulty pouring a kettle, twisting door handles and wiping my backside is an issue that will not improve!!

Everything else seems ok though. The wife is as straight as a die and is happy that there is no lasting soft tissue damage, even though she was bruised by the bike landing on her.

 

[Bendy toy]

I edited it again because I thought you had said radial head fracture but hey your's isn't a bowl of cherries.

I can't pm you but I am a chiropractor and see many people who had seemingly minor (and sometimes not so minor) injuries that were not properly managed in the recovery stages. Those are the things that come back years later. We aren't magic, but can do a lot to reduce long term problems.

email me on david dot e at hotmail dot co dot uk

As said about the bike nobody can say the driveshaft failure was not accident damage so the insurers should fix it and check all the other drive-line stuff.

 

[Mr Bean]

Thanks, I'll drop you a message.

 

[jwpzx9r]

Not totally relevent but lifted straight out of a guide for jurors to understand speed and impact injuries sustained at certain speeds. I don't fancy the outcome of the bit it bold!

A fall off a 3.3 feet desk results in a speed at impact of 10 m.p.h. A 10 m.p.h. change in speed (Delta-V) in a motor vehicle collision is equivalent to falling off a desk. Similarly, a 15 m.p.h. change in speed is equivalent to falling 7.5 feet - off a step ladder. A 20 m.p.h. change in speed is equivalent to falling 13.4 feet - off the roof of a one story building. A 25 m.p.h. change in speed is equivalent to falling 20.5 feet - off a two-story building. A 30 m.p.h. change in speed is equivalent to falling 30 feet - off a three-story building.

 

[Mr Bean]

Not totally relevent but lifted straight out of a guide for jurors to understand speed and impact injuries sustained at certain speeds. I don't fancy the outcome of the bit it bold!

A fall off a 3.3 feet desk results in a speed at impact of 10 m.p.h. A 10 m.p.h. change in speed (Delta-V) in a motor vehicle collision is equivalent to falling off a desk. Similarly, a 15 m.p.h. change in speed is equivalent to falling 7.5 feet - off a step ladder. A 20 m.p.h. change in speed is equivalent to falling 13.4 feet - off the roof of a one story building. A 25 m.p.h. change in speed is equivalent to falling 20.5 feet - off a two-story building. A 30 m.p.h. change in speed is equivalent to falling 30 feet - off a three-story building.

Interesting info.

I don't think I said that I hit the van at 30mph.

Imagine the scenario. I have just done a quick stop, I am stationary with my hand still gripping the front brake. A small van impacts the rear at whatever speed it was, the wheel and tyre deform absorbing some of the force, it is likely that other deformation also absorbed some of the impact, i.e. footrest hanger, rear subframe which returned to it original position whilst other parts may not have - the footrest hanger needed to be straightened.

The bike is now being forced by the impact in to the rear nearside corner of the van - slowing down all the time. The offside bar with my hand still gripping the front brake, trying to avoid colliding with the van. I hit it with enough speed to shatter my right wrist.

I suspect if it were at a low speed the bar would have been pushed to the right and I wouldn't have had the fracture.

 

[Bendy toy]

I think its reasonable to say there was a significant impact but TBH 30mph would have done more than badly break one wrist.

But as said it doesnt matter what the speed was. The bike was hit from behind by a myopic driver. Bike and car were damaged and Mr bean has a badly damaged arm.

The driver failed to stop in time so was not paying attention. He/she should have got more than a retraining course.

 

[Mr Bean]

Thanks for your input and support.

Now we have finished with the accident does anyone know if the impact could have caused the the telescoping of the drive shaft to bottom out?

I bear no ill will to the driver. I have on more than one occasion over the past 30 years needed to apply the brakes in an emergency because I wasn't paying enough attention - fractions of a second are the difference at times.

 

[Bendy toy]

It cant be proved but it all failed just after the post-crash rebuild. IMO it reasonably could have been damaged in the crash. After all the hub bearings (IIRC) and wheel were replaced.

I once had a car insurance repaired after a front wheel hit a kerb after sliding on ice. The impact was under 10mph but the car was unusable.

It came back with a clicking from the repaired front wheel which the repair garage were happy to ignore. I drove the car slowly on full lock and the CV joint could be heard clacking away. I refused to accept the car. They then replaced the drive shaft and wheel bearing and all was fine.

This doesnt exactly correlate with a rear-ended BMW FD but they did accept a problem still existed and sorted it out.

 

[ianm00]

I have just been told that I need a drive rebuild due to leaking outer seal and play on the bearings.

I thought the advantage of shaft drive over chain was maintenance free and would outlast the life of the bike. My bike has done 75K miles but I had an old yamaha divvy 900 which did many more miles and the only thing done to the shaft was replacing the oil.

Why are BMWs failing? Some at very low milages eg less than 20K?

My real question is if I have the rebuild done what is the expected milage before another re-build would be required?

Ian

 

[Sgt Bilco]

I have just been told that I need a drive rebuild due to leaking outer seal and play on the bearings.

I thought the advantage of shaft drive over chain was maintenance free and would outlast the life of the bike. My bike has done 75K miles but I had an old yamaha divvy 900 which did many more miles and the only thing done to the shaft was replacing the oil.

Why are BMWs failing? Some at very low milages eg less than 20K?

My real question is if I have the rebuild done what is the expected milage before another re-build would be required?

Ian

You thought wrong old chum. Nothing lasts forever and 75k is pretty good. Get the rebuild done by Mikeyboy for £350 and you will be good to go for another 75k.

It's pot luck on drives from the factory so a rebuild by someone competent with good bearings is the best option.