I'll jot this down in my little notebook of things to tinker around with when I have spare time. Perhaps just replacement stars made of a more suitable material (maybe hardened 440C) would fix this for a lot of people. I have a spare engine, and enough left of the star to model a new one up. Also, knowing the theoretical nominal distance between the center of the shift drum, the pizza cutter wheel, the number of degrees it needs to move out of the way to clear an in tolerance star point for each gear and the angular distance on the star for between gears, it might be possible to design a plunger style unit that has a roller mounted on the end of a detent that doesn't require radial force. Maybe there is a point where it will work for a longer time without wearing as bad as long as you aren't hammering through the gears trying to break something. I can also calculate shift drum rotational speed and attach my mad scientist experiments to a stepper motor and cycle it a few hundred thousand times and watch for wear. I have the means to evaluate the springs function in situ or an analog of installed state and decrease the pressure 5% at a time and see what happens. To be clear to everyone, I am not promoting people run for the nearest dremel and damage your bike or potentially parts that are hard to replace - consider this a disclaimer - please don't do that. Has anyone suggested weaken the spring so this will stop happening? It seems like massively over sprung.Īs far as the cases, I wonder if I was just getting cheap with the solution in the ultrasonic and maybe a fresh bath of new chemicals might solve it. That thing is made of woodpecker lips, because it has ZERO wear to the point you can still see the imperfections from the stamping process. The paranoid in me wants to high temp silver solder the pin in as a precaution, but I not want to ruin the temper of the wheel. In the meantime, I fabricated a new rivet from a Class 12.9 bolt and staked it in. From a manufacturability standpoint, I see why the did what they did, but I might be able to solve this problem for good. It is a pretty poorly designed part and could be improved upon pretty easily as a screw/stake together assembly where the wheel is riding on a machined boss with a bronze sleeve to even out the load. I will probably repair the spare shift stopper, but given the only one I found for sale NOS was $115, I should probably make some. The shift star was pretty badly damage, so I harvested the shift drum, input shaft, output shaft, forks and all associated parts from the spare engine with substantially less miles. I have already repaired the shift drum stopper and will likely rerivet the neutral stopper while I am at it.
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