07-07-2016, 09:11 AM
(07-06-2016, 04:01 PM)dsinned_imp Wrote: The cynical reason is to make more money for Honda Dealers, but surely there must have been a technical reason. Although, I can't think of any reason why not. OTOH, I may not log more than 8,000 miles, during the short number of years I have left as an active motorcycle enthusiast due to my advanced age. ;-)
Mate, there are, in fact, technical reasons that shim under bucket is a preferred configuration. Efficiency, that is less mechanical drag; shims can be made smaller thus reducing valve train weight; shim under bucket does not "spit" shims (as opposed to shim over bucket); reduced valve float at high RPM; less requirement for adjustment than other adjustable systems. The prime disadvantage is that when adjustment is required the cam has to be lifted. But, believe me, on the CB it is not such a big deal for the home mechanic. However, at whatever your dealer charges out his labour, it can be expensive if you need to get the dealer to do it. In short, it's really the preferred system for modern performance motorcycles. If you wanted to optimise Flynrider's Nighthawk's performance it would be the system of choice. OK, the CB is not a "performance" motorcycle but Honda specs it well. I wouldn't really want the CB to go back to balancing carbs, adjusting tappets at regular intervals, relining and adjusting brake shoes, cleaning and setting points, adjusting timing and all the myriad things I still have to do on my '61 T120. If all these things had to be done on a modern motorcycle, at today's rates, then Honda might very well make a lot of money on their margins.
8000miles is not a big deal. I consider you to be still a youngster and I reckon I should have another 100000kms left in me, with luck that is.
. Cheers