[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

Conference noted::bicycle

Title: Bicycling
Notice:Bicycling for Fun
Moderator:JAMIN::WASSER
Created:Mon Apr 14 1986
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:3214
Total number of notes:31946

2274.0. "Avocet 50 Problem" by BTOVT::BESSETT_K (Have Guitar & Computer...will Travel) Fri May 08 1992 11:04

    Hi, I'm having a problem with an Avocet 50 bike computer. 
    
    
    The odometer is off by .2 every 5 miles; No matter what I calibrate the
    wheel to.  I used the value they gave in the manual for a 700x20c and I
    also took the rolling circumferance and  plugged that in.  
    
    Is their a sequence I'm not following when I change the wheel
    calibration?  The sequence I follow is to hold both buttons for 8
    seconds, the press the right button until I get to the wheel
    calibration, and then modify the number.
    
    
    Thanks,
    Kevin.
T.RTitleUserPersonal
Name
DateLines
2274.1Nothing obviousMOVIES::PAXTONAli Baba (TM) was a marketeerFri May 08 1992 12:3816
    Did you take the rolling circumference with you on the bike ? When I
    tried it, I found it very difficult to be accurate that way. The
    numbers in the book are just guidelines which I wouldn't trust too
    much. The only true way is to measure your distance against a known
    course and compensate for the percentage you're out. Which begs the
    question, how do you know you're out by the amount you state ?
    
    You're doing the button-pressing right, as far as I remember it.
    
    Beware that there's a bug in the Avo 50 which has the effect that
    old accumulated distance is changed when you change the calibration.
    They store distance as wheel turns and scale it by the current
    calibration to display the distance. So reset the _trip_ distance to
    0 and always use that when you fiddle with the calibration.
    
    ---Alan
2274.2Maybe a problem inside the computer????BTOVT::BESSETT_KHave Guitar & Computer...will TravelFri May 08 1992 13:2114
    Alan,
    
    I did plug in rolling circumferance with me on it.  It was off by
    .2 every 5 miles.  Then I decided to try the number they gave, and I 
    was still off by .2 miles.   I'm going against milage that my truck
    read for this distance.  I verified that my truck odometer measures
    correctly on the interstate (with the mile markers).
    
    It's almost like I can't change the cablibration figure of the
    computer.  It changes on the display, but seems not to change the
    computer.  I'm going to drastically change the calibration number before 
    I head home tonight....to verify this problem.
               
    Kevin.
2274.3Ride with five riders and really see some differences.NEGDWB::DELORIEAI've got better things to do.Fri May 08 1992 16:233
Maybe the computer is right and the world has it all wrong.

Hmmm 
2274.4LJOHUB::CRITZFri May 08 1992 16:296
    	I've found that my bike computer is more accurate than my
    	car.
    
    	Could it be your computer is right and your car wrong?
    
    	Scott
2274.5Maybe I've got a bad computer??BTOVT::BESSETT_KHave Guitar & Computer...will TravelWed May 13 1992 13:5315
    I verified the odomenter on the car using mile markers on the
    interstate.  It was spot-on.  I only did this for one mile, however.
    I'm assuming that because of the accurricy in one mile, the odometer is
    reading milage correctly.
    
    I'm wondering if I've got a bad computer because I had to calibrate the
    computer for a wheel that is an inch bigger than my wheel's rolling
    circumferance.  Also, when I finish a ride, I stop the stopwatch but
    milage keeps accumulating and my avg. speed starts decreasing as I
    spend time cooling down.  Maybe this is the way the computer is suppose
    to work (as far as the stop watch), if it is, I'm not impressed.
    
    
    
    Kevin.  
2274.6Mine too...ODIXIE::RRODRIGUEZI think I know a short-cutWed May 13 1992 15:188
    I have an Avocet40 with the same feature.  I can't turn it OFF to
    "freeze" my trip distance an average speed.  I could do this with
    my Cateye Micro.  A couple f suggestions on calibrating: go to
    the local high school and use the track or check metric/English
    mode...
    
     2
    r
2274.7hintYNGSTR::BROWNWed May 13 1992 17:475
    I just slide the Av50 slightly forward on the mount so the pins don't
    make contact when warming down and I don't want it to affect the avg
    speed.  I have mine setup so that it can be slid forward to do this,
    but can't be removed (easily by hand) or fall off cuz it runs into the
    aerobar if moved further forward. -kb  
2274.8On a slightly different tack...IDEFIX::HEMMINGSLanterne RougeThu May 14 1992 03:369
I tried out a Sigma 300 I had intended to put on my wife's bike - first time out
it appeared to be reading about 1/2 what I expected in both speed and distance.
Being a computer expert and also an engineer, I immediately diagnosed that it
was most likely in Imperial mode instead of Metric.  I checked when I got home -
no, it was fine.  Then I got to wondering just why they had given me a "spare"
magnet........

I think I had better stick with measuring on the maps, these things are obviously
too technical for me !!
2274.9Yet more about the A5052908::PELAZ::MACFADYENRound up the usual suspects!Thu May 14 1992 05:2322
Re Avocet 50 queries:  The only function that you can turn on and off is
the stopwatch. Distance, climb, ave and max speed all accumulate whenever the
wheel is turning. For me, this is fine. I also have a Cateye 7000, and I've
lost count of the times I've forgotten to turn it on or off, or done this
accidentally.

Coming back to the Avocet, remember that all the functions can be zeroed
individually. So if you want to record your average speed over a set course,
zero the ave speed as you start the course, then read it as you finish. One
thing to remember about the Avocet ave speed, is that it only measures your
*cycling* average - it doesn't take any stops into account. Of course, this
looks better...

As far as calibration goes, I'd question the base-noters assumption of the
accuracy of his truck odometer. Fair enough, you measured over a known
distance. But *one* mile? Does your truck's odometer read any more accurately
than tenths of a mile anyway? I think you'd want to be checking against a
much longer known distance, say 10 miles. And if you have known distances,
why not just cycle them and set the calibration that way?


Roddy
2274.10Phew... (Wot a scorcher - The Sun, VBO, 14-May-1992)IDEFIX::HEMMINGSLanterne RougeThu May 14 1992 06:498
re .9

Am I glad I only have a cooking model Sachs-Huret - it does instantaneous + trip
+ average while the wheel is turning.  There is one button that zeroes every
thing except cumulative, which I don't use anyway because I use several bikes
and changing the battery destroys it anyhow..........

Biking is supposed to be easy - KISS      ;>)
2274.11BTOVT::BESSETT_KHave Guitar & Computer...will TravelThu May 14 1992 11:1018
    Last night I took the truck on the interstate and travelled five mile
    markers.  The odometer was off by  ~.13 by the fifth mile.
    
    I'm feeling now that the initial calibration number I plugged into the
    avocet--and the distance it was recording--was sort of accurite.  
    
    What I'm going to do is measure the rolling circumferance in metric,
    plug it in as metric and then convert back to english, afterwards.
    
    
    Regarding the stopwatch, I guess I was figuring it worked like the
    previous to computers I've owned (when you press stop, it doesn't
    record anything)
    
    Thanks for the help,
             
    Kevin.