Experimental clutch, version 2.0
Last year, I made the version 1.0 experimental clutch mod, using adjustable features that I felt was not suitable for others to implement. After determining the settings and measurements, I made the parts for the version 2.0 earlier this year. Now that I've got a few months and about 1000 miles on the thing, it's time to reveal.
To fully understand this mod, here's the previous, original threads:
http://www.xs650.com/threads/yamaha-xs650-experimental-clutch.47498/
http://www.xs650.com/threads/finding-neutral-while-stopped-and-in-gear.47568/
The concept and principle is really quite simple. All that happens is the plates are "pulled" apart, accordion style. When the pressure plate moves outward a few thousandths, it pulls on the adjacent steel plate. When that plate has moved outward a few thousandths, it pulls on the next adjacent plate. And so on, until all the plates have been pulled outward equally. A clutch plate "spreader", if you will. Doesn't use any spreader springs which would compete with the clutch's compression springs.
To do this, takes advantage of a feature that I believe is unique to the XS650 clutch. The large exposed annular space between the clutch hub and the ID of the friction plates. This area was once occupied by the "damper" o-rings on the early bikes. Long discontinued, the space previously occupied by those o-rings is large enough to fit small #2-56 machine screws that connect the steel plates.
Although the concept is simple, the execution is painstakingly tedious and complicated, requiring drill fixtures and darn near watchmaker precision. Holes must be precisely positioned, drilled, and tapped. Shoulder screws, with specific diameters and lengths are used.
The mod consists of drilled and tapped holes, and 21 shoulder screws. Spread uniformly about the clutch, this adds only 4 grams to the clutch weight. Since the holes and screws only occupy the unused region of the clutch, they have no other impact on clutch operation. And, the screws can be removed to return the clutch to its original configuration...
Last year, I made the version 1.0 experimental clutch mod, using adjustable features that I felt was not suitable for others to implement. After determining the settings and measurements, I made the parts for the version 2.0 earlier this year. Now that I've got a few months and about 1000 miles on the thing, it's time to reveal.
To fully understand this mod, here's the previous, original threads:
http://www.xs650.com/threads/yamaha-xs650-experimental-clutch.47498/
http://www.xs650.com/threads/finding-neutral-while-stopped-and-in-gear.47568/
The concept and principle is really quite simple. All that happens is the plates are "pulled" apart, accordion style. When the pressure plate moves outward a few thousandths, it pulls on the adjacent steel plate. When that plate has moved outward a few thousandths, it pulls on the next adjacent plate. And so on, until all the plates have been pulled outward equally. A clutch plate "spreader", if you will. Doesn't use any spreader springs which would compete with the clutch's compression springs.
To do this, takes advantage of a feature that I believe is unique to the XS650 clutch. The large exposed annular space between the clutch hub and the ID of the friction plates. This area was once occupied by the "damper" o-rings on the early bikes. Long discontinued, the space previously occupied by those o-rings is large enough to fit small #2-56 machine screws that connect the steel plates.
Although the concept is simple, the execution is painstakingly tedious and complicated, requiring drill fixtures and darn near watchmaker precision. Holes must be precisely positioned, drilled, and tapped. Shoulder screws, with specific diameters and lengths are used.
The mod consists of drilled and tapped holes, and 21 shoulder screws. Spread uniformly about the clutch, this adds only 4 grams to the clutch weight. Since the holes and screws only occupy the unused region of the clutch, they have no other impact on clutch operation. And, the screws can be removed to return the clutch to its original configuration...
