We know those chains too, but we never decided to use them according to the following facts and that's
the reason why we only supplied the stronger version without holes to Ken.
One of the biggest difference is that those chains have been manufactured with pressed bushings with seams
(like stock RK) in order to reduce costs of manufacturing instead of using hardened seamless bushings.
On those chains, the seams are aligned to the opposite side of the sprockets.
RK did not take care about this back in the days. In fact, the hole on each bushing is not a
lubrication hole (of course, everybody calls it mistakable lubrication hole).
It is a center hole for automatic positioning of the bushing seams on the opposite side of the
crank and clutch sprockets to make sure, that the bushing seams do not touch the sprocket
bcause the seams are the weak point on the bushings.
It's not a roller chain, bushings and pins are not rotating, so no additional lubrication is needed?
Pressed bushings with seams are not that strong as seamless hardened bushings and they are cheaper
to manufacture with less strength what results in a lower manufacturing and sales price.
Of course, holes do not weigh anything, so they are lighter.
Some physical rules:
The holes are located on the outside of the chains as you can see on the pictures above.
If the holes would be lubrication holes the oil would float out of the hole by centrifugal
force but never would find the way inside, especially with high revs like engines produce.
(same effect which Honda has been used for the automatic drive chain lubrication on the earlier CB750s).
It would be needless too, the HD chains and RK chains do not need more lubrication, which those chains do not supply, too.
If there should be a lubrication effect, the holes should be on the inside of the chains to get filled by centrifugal force
(compare the centrifugal force lubrication effect on the early Honda automatic drive chain lubrication again).
This would mean, that the weaker seam side of the bushing with the hole would hit the sprockets.
It would not be an improvement in comparison with stock RK chains.
Those chains will not stretch that much as stock RK chains, but noticeable more than the HD chains without the hole and seamless hardened bushings.
A long term test will show it and we can compare it with our personal results.
We are far away to blame a product we do not sell, but we wanted just deliver some facts according to the better, faster, cheaper, lighter discussion
w/o supplying data details or a data sheet.
And in fact, they are an improvement of the stock RK chains only.
A data sheet of those chains would be helpful, too.
nippon
