Re: [ST] Suspension upgrade (was: Sprint ABS)

["Sprint ST" <sprint_st@xxxxxxxxxxx>]

Matt makes an excellent explanation of damping.  Blake does make an
incorrect statement that emulators (I'm assuming Blake is talking
specifically about RT emulators) have some way to adjust for high and low
speed compression and rebound.
>An emulator gives you independent control over both the compression and 
>rebound settings on the front forks. It also has different settings for 
>high-speed (sharp) bumps versus low speed (gentle
>oscillations) bumps.
Many good cartridge forks do that.  RT emulators only have one adjustment.
That controls a diaphragm which controls oil flow rate in both directions.
That one setting is all you have for both directions.  So whatever setting
you choose it is probably some type of compromise but at least better than
the one hole you get with a damper rod.  

This may be what Matt was saying with different words.  It has always been
my impression (the internals of shocks and forks are way over my pay grade)
that all damping was done with oil flow rates which impede the spring
compression or rebound.  Both progressive and straight rate springs are
dampened by the cartridge or the damper rod method of oil flow control.  The
spring is the brute force in the fork and the cartridge or damper rod
provides the finesse.  

Most of the progressive springs, to include the stock 99-04 springs are
actually dual rate springs.  Companies like Progressive make some one size
fits all progressive springs.  HyperPro, if you believe their propaganda,
makes a spring designed for a particular bike.  I found it to be way better
than stock, but not perfect.  The RT emulator definitely cleaned up the
minor flaws in the spring.  My guess is that the diaphragm can provide much
better initial flow rates than that single hole which has to get by
hydrostatic lock before it becomes useful.  It is also faster reacting than
the lighter portion of the spring.

Rod


They that can give up essential liberty to obtain a little temporary safety
deserve neither liberty nor safety. 
Benjamin Franklin 

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