2004 BMW R1100 S problems

Filed Sep 8, 2014 · Fuel system, Transmission · 33,861 miles · VT

I was traveling at 47mph and as I shifted from 4th to 5th gear, the bike suddenly lurched with a bang as it decelerated and I lost the ability to accelerate. The engine revved as if the bike was in neutral with the throttle engaged even though I should have been in 5th gear. I twisted the throttle back to zero and tried to shift into other gears. Even though the shifter was working, the bike would not engage into any gear and was moving only under it's own momentum. There was a grinding noise which was prevalent. I coasted to a stop and tried shifting gears again, but could not get the bike to engage. I heard loud grinding noises when trying to put the bike in gear and then it would stall. After being towed, the bmw dealer confirmed clutch spine failure as root cause. There are numerous incidents of this failure documented on the internet, especially on the r1100s. In looking at the failure itself, one can see that the input spline shaft teeth are about 3/4 sheared as are all the splines on the clutch mating plate except for the ends furthest away from the input shaft. This is a design error since the input shaft is 8-10mm short and does not fully engage the full length of the clutch mating splines. Therefore load and torque are not equally distributed amongst the full length of all the spines, which results in premature failure. It also appears that the input shaft was not correctly aligned to the chassis upon initial build. The fact that the design does not fully mate all the splines and that it wasn't aligned correctly when built are the root cause for this failure at less than 34,000 miles. Not only is this a costly repair since the entire bike needs to be dis-assembled, it also has the possibility of creating a fatal safety situation depending on if the fail were to occur in heavy traffic, around a curve or when carrying a passenger.