Rich,

I'd say you're right on the money with that.  When I'm reading 65 or 70 mph, I
am really doing about 5 mph less.  I have had three Z-Rexes, and this latest one
reads more accurately than the first two.  Not sure why...

Todd
Silver City, NM




________________________________
From: rich_betz <h20-k9@...>
To: zrx1100-1@yahoogroups.com
Sent: Thursday, November 6, 2008 6:49:01 PM
Subject: [ZRX1100] Re: sprockets


Yep, yer right. The main sprockets have no effect on the speedo,
however what chris was asking is
"what is the percentage of error of the speedo?"

I have had my GPS gadget on the bike many times, and it is 5MPH
optomistic at an INDICATED 60MPH. I don't have a spreadsheet of
speeds, but I can say that the error increases as speed increases.

At my INDICATED 150MPH, I would give a good guess that I might only be
doing somewhere around 140 or maybe even less, but we all know that we
use the bragging rights of the better of 2 numbers.

About 4yrs ago, I retrofitted a digital speedo/tach into my original
Vmax speedo housing. You have to calibrate the speedo by driving along
side another KNOWN GOOD SPEED SOURCE. Instructions recommend another
car, I used my GPS. In this day and age, your most accurate
measurement of speed is going to be GPS or RADAR. The speedo is
calibrated at a measly 45MPH but I will trust the accuracy of a
digital signal over the mechanical drag of gears and the typical
unlubricated speedo cable.

After years of blasting around on the Vmax with the factory speedo, it
seemed REALLY FAST as indicated by the factory speedo. After hooking
up the digitally calibrated, digital speedo, you would be amazed
(disappointed) as to how much slower you are actually going.

From that experience, when I hear other Vmax guys who are 225+lb fat
asses like myself, when they say they run their Vmax at 145 to 155+
all day long, I know they are sadly fooling themselves. Their factory
speedo's are just as inaccurate as mine was. The Vmax is no slouch,
and there are definately one's faster than mine, but I can tell you
that they are NOT EXACTLY as fast as the owners think they are.

OK, I know, not exactly sprocket talk, but......... .

Later,
R.Betz

--- In zrx1100-1@yahoogrou ps.com, econes <no_reply@.. .> wrote:
>
> Good news. Speedo operates off front wheel. You can mess with your
gearing all you want without affecting it.
>
> --- In zrx1100-1@yahoogrou ps.com, chris burgess <cvb302@> wrote:
> >
> > Sounds great. How bad is the speedo off?
> > Date: Wednesday, November 5, 2008, 2:27 AM
> >






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