RE: [ST] Front fork bottoming with RT Valves

["Jeremy Witt" <jeremyw@xxxxxxxxxxxxxx>]

There's PVC pipe in my Hawk front end as spacers on top of the RT
springs (and GV emulators).  Cheaper than aluminum, but heavier, I
guess.

Jeremy Witt
Field Engineer
Corrugated Networking Services Inc.
Office: 603-703-0365



-----Original Message-----
From: st-triumphnet.com-bounces@xxxxxxxxxxxxxxxxxxxx
[mailto:st-triumphnet.com-bounces@xxxxxxxxxxxxxxxxxxxx] On Behalf Of
simonb
Sent: Friday, September 16, 2005 4:55 PM
To: ST@xxxxxxxxxxxxxx
Subject: Re: [ST] Front fork bottoming with RT Valves

On Fri, 2005-09-16 at 13:13 +0000, sprint_st@xxxxxxx wrote:
> Simon,
> I think you said you went about 220lbs???  When I ran the RT
"computer" at
> around 220 it said 0.75Kg/mm for springs and that was even with
options
> for racing, expert and prefer stiff.

It said 1kg when I looked 750kg/mm is standard Triumph ST

>  (my experience with that "computer"
> has been it really doesn't change much except for rider weight)  That
> means you have a spring that should be more stiff than required,
unless it
> is totally the wrong spring and mismarked - that does happen.  You can
> check that because that rate is just what it says, it takes three
quarters
> of a kilogram to compress one mm if spring travel.
> 
> As far as fork oil going to water (I know, not literally), I find that
> hard to comprehend.  The original was somewhere around 7wt (no one
> including Showa seems to be able to give a good, exact answer on that
one)
> which is pretty light anyway.  Even 15wt fork oil feels pretty light,
but
> that stuff doesn't come close to taking the abuse of engine oil so it
is
> really hard to understand how it would undergo such a change in its
> physical properties.

It doesn't change its properties. But water seams to get into the oil
through the seals. I haven't had a look as yet but will do soon. I will
take the tops off the forks and put the jack under the front wheel to
push the wheel up to the top. You have to measure the distance wit hthe
forks compressed.

Is still haven't found out if it's a mechanical or hydraulic bump stop.

> 
> I do not use RT springs on my ST but did on my last bike.  They were
> significantly shorter than my stock springs.

You get an aluminium tube to cut to size.

>   That could be a factor, but
> there are a lot of guys using RT straight rates that don't bottom.  My
> HyperPro's state in their marketing literature that they flat won't
bottom
> out and mine sure have not, but then again they are the "inferior"
fully
> progressive springs.
> 
> Hope I'm not being a pest.  This subject intrigues me.  I just rebuilt
my
> forks, even though they didn't need it.  New bushing, seals and RT
> emulators.  If you do find an ultimate cause, I sure would like to
know
> what it is.

I shall have to go and have a look.

-- 
simonb <simonb@xxxxxxxxxxx>

_______________________________________________
Triumph Sprint ST/RS mailing list
Send list posts to ST@xxxxxxxxxxxxxx
Change your list options at www.Triumphnet.com


_______________________________________________
Triumph Sprint ST/RS mailing list
Send list posts to ST@xxxxxxxxxxxxxx
Change your list options at www.Triumphnet.com