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View Full Version : boysen pro series or rad valve?



400exracer511
06-25-2005, 07:24 PM
is a boyesen read valve or other reed cage worth the extra money or is it jsut as good to go with replacement reeds for the stock cage like boyesen pro series reeds

thanks

400exracer511
06-25-2005, 07:27 PM
also what is better boyesen rad valve or v-force 3 reed valve if anyone has these and can tell us how they worke out that would be nice

thanks again

06-25-2005, 08:02 PM
I have boyssen Rad valve and love it.... Vforce supposedly is better but im not gonna spend that kind of money to find out, i have more than enough power.

Think of a reed valve like a carburetor, bigger valves with large flow-areas work best for high rpm power bands. In general, reed valves with six or more petals are used for high rpm engines. Reed valves with four petals are used for dirt bikes that need strong low end and mid range power. There are three other factors to consider when choosing a reed valve. The angle of the reed valve, the type of reed material, and the petal thickness. The two common reed valve angles are 30 and 45 degrees. A 30-degree valve is designed for low to mid rpm and a 45 degree valve is designed for high rpm. There are two types of reed petal materials commonly used, carbon fiber and fiberglass. Carbon fiber reeds are lightweight but relatively stiff (spring tension) and designed to resist fluttering at high rpm. Fiberglass reeds have relatively low spring tension so they instantly respond to pressure that changes in the crankcase, however the low spring tension makes them flutter at high rpm thereby limiting the amount of power. Fiberglass reed petals are good for low to mid power bands and carbon fiber reeds are better for high rpm engines.

Boyesen Dual Stage reeds have a large thick base reed with a smaller thinner reed mounted on top. This setup widens the rpm range where the reed valve flows best. The thin reeds respond to low rpm and low frequency pressure pulses. The thick reeds respond to higher-pressure pulses and resist fluttering at high rpm. A Boyesen RAD valve is different than a traditional reed valve. Bikes with single rear shocks have off-set carbs. The RAD valve is designed to redistribute the gas flow to the crankcases evenly. A RAD valve will give an overall improvement to the power band. Polini of Italy makes a reed valve called the Supervalve. It features several mini sets of reeds positioned vertically instead of horizontally like conventional reed valves. These valves are excellent for enduro riding because of improved throttle response. In tests on an inertia chassis dyno show the Supervalve to be superior when power shifting. However these valves don't generate greater peak power than conventional reed valves. Supervalves are imported to America and sold by Moto Italia in Maine.

06-25-2005, 08:12 PM
yeah if you got the money go with rad if not the v-force is almost as good

06-25-2005, 08:20 PM
Almost the same price 10-15 bucks difference so its up to you.

Believe i gave you the info you need to select which one is best for you.