Of course, I spent more money for the harder primary rubbers in order to see them in person in comparision with the other rubbers. First, I wanted to use them.
Then I decided not to use them in my engine (please see reasons above). Please do not misunderstand, it does not matter how much the different rubbers cost.
According to your helmet example. I'd rather like to protect my engine components instead of replacing them several times during a race/street season. It is not about the price. I would not throw away my helmet after every ride, too. (IHMO, the molded primary rubbers are a much more better engineerd and developed (and a more expensive) part). But the club rubbers are subzidized to the members, so they are cheaper than the the harder ones.
I know, that you didn't have a chance to see them in person w/o being a member.
I measured both types of rubbers, the difference between the harder rubbers and the softer club rubbers is approximate 12% (shore). It sounds not that much, but it is a huge difference. We do not talk about chewing gum. From my point of view, the soft rubbers are hard enough to do the balancing and damping job very well (see above) , even in tuned engines and they protect the abrasion of the involved primary drive components (chain and crank sprocket). This is an important point for me and all non professional racers, too. I'd rather would like to replace worn primary rubbers instead of a crank (but this is not the case until yet. they are perfect.). I never heard a negeative feedback from my classic race (not GP) buddies about the 'softer' primary rubbers and they use them all for years. Of course, there is big difference. If I would ride my bike only a quarter mile like R.C. did, ...with welded primary sprockets and replacing them after every run, or if I want to ride my bike for a whole race or street season w/o replacing primary chains and cranks.
There is the difference.
Mark, i know, you are a serious racer and your are hunting for the max power w/o any compromises, but how many times do you or your mechanics disassemble your engine during a race season in order to replace the primary chains and crank? Woud a 'normal' rider do that? Mark, how long will your involved primary drive train components last? Your primary chains and sprockets are worn much more faster with much more harder primary rubbers. You know, if the chains are too long, they want to climb over the crankshaft sprokets, especially during alternation of loads and deceleration. Softer rubbers will almost avoid this or they will delay it under race conditions because they protect the chain and crank sprockets much more better. Until yet, i did not read anything about the durability of your primary drive train components.
It is a logical process, harder rubbers will abrase your primary drive train components much more faster than softer primary rubbers. Why did so many guys try to convert the primary drive train into an automatic crank and Hi-Vo chain? And, i repeat, harder rubbers cannot balance the power between the independent primary chains until they receive the equal power from the crank. E.g., with a Hi-Vo chain and automatic crankshaft, you do not need primary (soft) rubbers to balance the chains, but with two independent and poorly made RK stock chains, there is a need to balance the power of the chains until the two single chains receive the equal power from the crank. This is one of the primary goal of the primary rubbers in my opinion.
In case of the poorly made stock RK chains, one of the independend chains will receive more power during the beginning of acceleration and deceleration. The rubbers will balance them.
Mark, you wrote:
"In actual operating conditions on street or racing conditions you DO NOT want to have the two cush drive sprockets moving independently."
Of course i want to have softer primary rubbers and a little movement of the sprockets in comparison with the harder ones, in case i do not have an automatic Hi-Vo cahin. With the given (two single chains) circumstances, we have to live with, what Honda gave us. In fact, two primary chains and two crankshaft sprockets.
I think, we speak about two different things. I speak about durability and a very good solution according to protect the primary drive train components and to quiten down the primary chain rattle to a like new condition with chains in good shape.
You speak about max. power w/o durability.
A serious question, would you remove the rear wheel rubbers inside the hub, too in order to get more power to the rear wheel from the drive chain?
From my point of view, with all efforts you are going to eleminate the function of the primary rubbers, you will increase
the abrasion of all primary drive train components. It does not matter if you have a stock or a heavily tuned engine.
It is just a question of time. But i understand that this is not important or the primary goal for a serious racer like you and your team are.
You need as much power as you can get.
Back to AshimotoK0, currently, The only chance to get the club made primary rubbers is to join the club.
They are reproducing much more parts like oil pump rubbers and springs, ignition springs and so on.
I think (not sure) the current price for a kit of primary rubbers with rivets is Eur 65.00 - Eur 70.00. Not too bad IHMO.
Then you could have your sample and you could start reproducing them,.......but calculate with a minimum of EUR 2000.00 to make your molds, material analysis and production.
I really do not want o make a club probaganda, that is not my style and my intention, I just want to explain the current situation. And honestly, I wish to have more skills in the english language to be able to write more detailed in order to avoid any misunderstandings.
nippon
