Computer for my Sun CX tadpole
#1
blochow2001
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Computer for my Sun CX tadpole
I bought and installed a Trek i9 computer and it does not work. I have been going back and forth with Trek customer service to resolve the problem and after about a dozen e-mails they don't know what is the matter and told me to return it.
To make a long story short the thing does not collect correct data. I can ride about 1000 feet and the odometer says I traveled 1 mile with an average speed of 18.2 mph. I don't think so.
So my questions is, what brands of computer do the riders out here use? I want to get a computer, but am leary of going through the hassle of buying from a catalog or on-line without knowing someone has had success with theirs. I have attahced a photo of the computer and sensor location on my ride, maybe someone can tell me if it is too close to the hub, Trek does not think so.
Thanks!
sensor1.jpg
sensor.jpg
stem.jpg
To make a long story short the thing does not collect correct data. I can ride about 1000 feet and the odometer says I traveled 1 mile with an average speed of 18.2 mph. I don't think so.
So my questions is, what brands of computer do the riders out here use? I want to get a computer, but am leary of going through the hassle of buying from a catalog or on-line without knowing someone has had success with theirs. I have attahced a photo of the computer and sensor location on my ride, maybe someone can tell me if it is too close to the hub, Trek does not think so.
Thanks!
sensor1.jpg
sensor.jpg
stem.jpg
#2
Portland Fred
This may be a dumb question, but did you calibrate it for your wheel size? Default settings would grossly overexaggerate speed and distance.
#3
Senior Member
The first thing I'd check is what banerjek already suggested. A 20x1.5" wheel would have a circumference of a little over 1500mm, maybe as high as 1550 for a 1.75" tire. A preset default value is probably something like 2150mm, which would cause you to read about 40% too high. Having the pickup too close to the magnet can sometimes cause multiple pulses per revolution, so the next thing to do is increase the distance between the sensor & magnet. What happens if you mount the sensor/magnet to another wheel?
#4
blochow2001
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Originally Posted by BlazingPedals
The first thing I'd check is what banerjek already suggested. A 20x1.5" wheel would have a circumference of a little over 1500mm, maybe as high as 1550 for a 1.75" tire. A preset default value is probably something like 2150mm, which would cause you to read about 40% too high. Having the pickup too close to the magnet can sometimes cause multiple pulses per revolution, so the next thing to do is increase the distance between the sensor & magnet. What happens if you mount the sensor/magnet to another wheel?
#5
Portland Fred
Originally Posted by blochow2001
Yes, I rolled it out, 59.5 inches, or 1511mm. I went through that with the folks at Trek, sent pics of how I rolled it out, pic of the measurement, pic of the tire size on the 'puter, and alos did a double check and got the circumference with the radius and our friend pi. I did all of that and it is still way off. changed the battery, moved the magnet around a bit and it did nothing to imporve the accuracy. I'm bringing the unit back tomorrow, and hope to hear back from other riders with what they are using. Thanks for the input!
I just find this to be such a bizarre problem. I wonder if the sensor isn't defective. When you roll the wheel, are the speed readings "even" -- i.e. do they consistently accelerate and decelerate as you do or do they hop around?
#6
blochow2001
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Originally Posted by banerjek
I use a Cateye Astrale (actually I have 3 of them). I think they're great.
I just find this to be such a bizarre problem. I wonder if the sensor isn't defective. When you roll the wheel, are the speed readings "even" -- i.e. do they consistently accelerate and decelerate as you do or do they hop around?
I just find this to be such a bizarre problem. I wonder if the sensor isn't defective. When you roll the wheel, are the speed readings "even" -- i.e. do they consistently accelerate and decelerate as you do or do they hop around?
Thanks for your input, I appreciate it.
#7
Take Your Lane
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Tech tips involving magnet orientation and distance from hub here:
https://sheldonbrown.com/cyclecomputers/index.html
Only other suggestion I have is maybe Trek computers are not compatible with recumbents or trikes.
(Kidding)
https://sheldonbrown.com/cyclecomputers/index.html
Only other suggestion I have is maybe Trek computers are not compatible with recumbents or trikes.
(Kidding)