Steve W. Posted January 27, 2008 Share Posted January 27, 2008 Found this over on the Advirider site. A guy is making new improved inputs shafts, longer and harder. Maybe the FIX!! http://www.advrider.com/forums/showthread.php?t=301863 http://www.advrider.com/forums/showthread.php?t=207014&page=10 http://www.sunshinecoast.ca/bmw/InputShaft.pdf Just passing along info on a common problem. No $$$ intrest for me. Cheers Steve Link to comment
T__ Posted January 27, 2008 Share Posted January 27, 2008 Found this over on the Advirider site. A guy is making new improved inputs shafts, longer and harder. Maybe the FIX!! http://www.advrider.com/forums/showthread.php?t=301863 http://www.advrider.com/forums/showthread.php?t=207014&page=10 http://www.sunshinecoast.ca/bmw/InputShaft.pdf Just passing along info on a common problem. No $$$ intrest for me. Cheers Steve Steve, I have been following that for a little while now.. A while ago he was looking for enough potential customers to get a production run started.. In fact the shaft has actually been listed for sale on a couple of web sites for a while now.. It might work, I have always wondered why BMW OEM used such a short spline shaft.. Problem is,, spending that kind of money & installation time to test a product for him.. Doing what I do for a living involves addressing many similar problems as the BMW clutch spline issue only in automobiles.. Sometimes what looks the best or what everybody thinks “should work” to control a certain problem or address a failure mode just flat doesn’t pan out,, or brings on other issues.. I have been fighting this for a long time now as we are rapidly replacing our older seasoned engineers with young ones just out of college.. The older experienced ones try to throttle the situation & demand thorough testing & long term durability miles.. Some of young ones in a lot of cases try to circumvent the testing schedule by making decisions based on what looks good to them or running a computer simulation on the issue.. Sometimes it works but a lot of the time it doesn’t,, or brings on side issues with other mating components.. Without thorough testing the cure could be worse than the disease.. Problem is the BMW spline problem doesn’t show up for many miles so we won’t know for quite a while if that new design shaft actually repairs the issue.. Or even adds other problems.. Plus I doubt anyone will disassemble their motorcycle to take a look/see if all seems to be working well.. I sure hope it works as that would take a lot load off peoples minds that have had spline problems.. If I was working with those new shafts I would be running a few in high mile test bikes (my cost & installation),, a few in extreme usage situations (again my people installing them to control installation process) ,, but would also have a test machine set up with side by side (OEM shaft/clutch disk) & (his shaft with new OEM clutch/disk) running 14/7 with rock cycles,, simulated shift cycles,, high torque power reversals,, low load shudder & idle rattle simulation,, high RPM moderate torque in the engine vibration/buzz RPM zone.. If it works (again I hope it does) maybe BMW will look into the issue or offer his product for over the counter sale… Twisty Link to comment
ragtoplvr Posted January 27, 2008 Share Posted January 27, 2008 I agree with the above post. I have not had a failure (knock on wood) or seen a failure with my eyes. So take this with a grain of salt. Many believe that the root cause is a misalignment, and the pictures of the failed and failing shafts sure seems to confirm that diagnosis. I also know from experience that it can be a challenge to properly fixture castings for machining. The long shaft does not address the root cause of misalignment, and being longer it may actually make misalignment wear worse by increasing the forces. That could be the unanticipated effect Twisty1 was referring to. When a step forms between the unused splines of the disk and the worn area, that can interfere with clutch release and might accelerate wear and produce some end loads not expected. Someone could much easier remove the excess splines from the clutch dish hub. While the misalignment would still exist, it might improve shifting, and might have an effect on wear. Hopefully that effect would go the right way. Now, back to hoping I got a good one. Just like I used to hope I got a good final drive. At least that was less money and work than a clutch/shaft job. I wanna ride. Damn freezing fog! rod Link to comment
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