Long Distance Competition/Ultracycling, Randonneuring and Endurance Cycling - Two computers

I've seen a few of the local randos with two computers, usually mounted -- quite ingeniously I thought -- to the same fork, in opposite directions, so that both run off the same magnet.

I opted instead for the Cateye Enduro which has two odometers; therefore, I hope I can zero one of them while keeping a running total on the other.

But is it standard to run two computers, not just for zeroing at turns, but in case one breaks down?

I don't even run one computer for brevets, not many run two of them.

<chuckle>

At PBP in 2003, I accidentally zeroed my single computer around the 240km mark. That upset things well and truly until I realised there were plenty of arrows pointing me in the right direction.

Blow me down if I didn't repeat the zero mistake on the Great Southern 1200 a year later! That made things a little trickier because there weren't any arrows. At one point I was in a lather thinking I was on the wrong road because my estimations were off and I was seriously running out of time... I had to stop a motorist to ask if the next town was indeed up ahead.

I now have an Enduro, too. I haven't zeroed it accidentally yet. I haven't got the instructions, either, but I fancy it might also cancel out your trip distance readings at 1000km and revert to zero. Unfortunately, I didn't get to test out that feature at PBP last year. I will try to do so on an Easter 1200 this year... if I ever get off my butt to do some training.

[Yes, yes, I could change the reading to miles and not have to worry about it cancelling out on a 750/1200, but unfortunately, the instructions on most my randonnees are in kilometres).

I did think about running two computers because my old Cateye did the cancel-out thing at 1000km, but it just means more wires running up the fork and through the brake cabling.

I've had computers malfunction on rides, but usually it has happened after the terminals have got wet. I usually notice fairly quickly when the readings are 0.00, and stop and scrape the terminals clean to solve the problem. Occasionally, it has been after I have fixed a front puncture and I've knocked the fork sensor out of alignment.

I don't recall having problems with batteries on a randonnee. Usually the problems manifest themselves in training (flashing display) or at home (fading display). It's a good policy, however, to carry the tiny battery in your handlebar bag. That way, you can spend an hour trying to remember where you carefully placed it so it would never get lost for when you need to replace the one in the computer. ;) :D

One other thing that comes to mind, is the calibration. I've tried all sorts of things, including measured distance markers on the road. I'm still trying to work out what is most accurate. And, then, that has to coincide with the organisers' definition of a kilometre/mile!

I've seen a few of the local randos with two computers, usually mounted -- quite ingeniously I thought -- to the same fork, in opposite directions, so that both run off the same magnet.

I opted instead for the Cateye Enduro which has two odometers; therefore, I hope I can zero one of them while keeping a running total on the other.

But is it standard to run two computers, not just for zeroing at turns, but in case one breaks down?

Sigma and VDO each make cyclocomputers with dual trip odometers in addition to the regular one. This can be handy late at night when you're tired and can't remember what your mileage was at the last turn. The second odometer can be set to count up or down so you could set it for the distance to the next turn or the distance to the next control.

Why someone has two computers is anyone's guess. I used to mount a Polar HRM/computer sensor along with a regular bike computer on the bike since I didn't always use the Polar.

I have, oddly enough, a Sigma and a VDO, the former on the folder, the latter on the road bike. I never use the fancy second odo. I don't know how, and I'm software developer with a Ph.D. Too complicated for me!

OTOH, I *do* run two computers -- I have a Garmin Forerunner 301 in addition to the regular wheel-pickup computer. Redundancy FTW! 14 hours of battery, though, would limit me to using it for maybe 300k rides without a recharge. Anyway, the "lap" button and screen are ridiculously easy to use and are very handy for tracking intermediate distances as part of an event or training.

...One other thing that comes to mind, is the calibration. I've tried all sorts of things, including measured distance markers on the road. I'm still trying to work out what is most accurate...

I use a GPS to calibrate the distance on the odometers. After a few >40 mile runs and a bit of tweaking they agree within 0.4% or better.

I have, oddly enough, a Sigma and a VDO...

I have two VDO's: An MC 1.0 and an MC 1.0+. The MC 1.0+ is an analog wireless and the MC 1.0 is wired. I have found that the wireless one is vulnerable to rf pickup which can greatly distort the readings. I have been out in the country stopped by a store and had it register 50 mph. Also, I have had a pace line of about twenty riders pass me and suddenly have about 10 miles added to the odometer. I now use the wireless one on my mountain bike and ensure it has fresh batteries.

Just a consideration if you are really counting on this for accuracy.

Depends on what you're doing and your confidence in navigation, equipment, group, etc. I run two separate odometers, one in my Polar and a Cateye. I've had them both malfunction or get reset on various occasions for various reasons. I can't imagine how you'd find the next control and/or stay on route on a long permanent or brevet without an odometer. We carry two or three headlamps, two tail lights, two tubes, a spare tire, extra batteries, extra spokes - none of which will help if you don't know where the next turn is. Retracing your route in the middle of a long brevet is not a morale booster. So I vote for redundancy.

I use a Garmin Edge 205 and a traditional bike computer (Cateye Astrale). The Garmin only runs about 8-hours per charge, even less if it spends a lot of time searching for satelites or if the weather is excessively cold or hot, so it's good to have a backup.

Also, the Garmin Edge doesn't have a cumulative odometer... I like to keep track of how many miles I'm putting on my bikes so that I stay on top of maintenance.

Edit: I do have a battery "booster" for the Garmin Edge. It's a portable charger made for IPods, and runs on AA batteries. I bought it on e-bay for about $10 and use rechargeable batteries with it.

I guess you could zero the odometer (not your trip meter) on your computer before the ride. This usually involves a reset button which is not likely to get activated by accident.
I just changed to a wireless backlit cateye as I have often had trouble in the wet with wired contacts.