Bicycle Mechanics - Astrale 8 - speed won't register. What to do?

I have an Astrale 8 on my commuter bike and for some reason the speed will not register. It is only two months old and the contacts look clean. Just wondering if you guys have any ideas. I think I will take it back to the LBS if it is not a simple fix. It could be that the chainstay sensor was bumped. How do I make sure it is in the right spot? Cadence is working fine. I also noticed that the odometer must have reset to zero at some point when I was fiddling with it. Is there any way to work around this by inputing the starting mileage?

Thanks for your help.

Might be the sensor, magnet, or one of the wires. Check and make sure a wire hasn't gotten cut by accident. Those wires are pretty flimsy. Mine quit working the other day too. The magnet on the spokes had slipped a bit and was not close enough to the sensor. Twisted it(the magnet) a little and......fixed. No, there is no way to input a starting mileage on tha Astrale 8. My wife's cheaper Cateye has that ability but my Astrale does not. Kinda silly if you ask me. :(

I bet the magnet is too far from the sensor...

When speed stops registering most often the cause is that the pick up has gotten bumped so that it is too far from the magnet. The sensor and magnet have to almost touch.

The second most common cause, particularly with rear wheel pick ups like the Astrale, is broken wires. I'll get back to that in a minute.

Before messing with the wire harness, try cleaning the contacts on both the computer head and it's base to see if that will make it work.

Back to the broken wire. The ultimate fix is to replace the wire harness. That's what a bike shop will do because it's a sure-fire fix and it's less labor intensive. If you can see where the wire is broken, and if you're adapt at that kind of thing, you can splice and solder them back together. If you have a hidden open or an intermittant contact somewhere, I'd just replace the wire harness.

Battery?

mine needs a good spanking to keep it going. the cradle seems to let the unit get too loose for good contact. sometimes jsut removing it and putting it back keeps it going.

I have an Astrale-8.

As I installed it, I tightened down the zip tie too tight and it cut into the speed sensor cable. I ordered another harness and reinstalled (used electrician's tape for most spots, and where I used zip ties, I added a little piece of spaghetti wrap around the cable first).

A week ago, the speed stopped registering, and I found I had bumped the sensor when loading the bike into the car so that it rotated enough on the spoke to not register when it passed the sensor.

I think these are the mostly likely scenarios.


Then there's my wife's computer (a Trek) that intermittently registers 100 MPH...

My Astrale 8 cadence readout stops periodically until I twist the head unit back and forth a couple of times in the bracket to improve the contact.

The magnet should pass within 1/8th inch of the sensor. If the magnet or the sensor have moved that could account for the lack of speed indication. But the odometer zeroing out sounds more like a dead battery unless you mean the trip odometer. An unused battery can go dead sitting on a shelf, but that seems unlikely.

Al

It wouldnt register cadence with a dead battery. I have had problems wiyh bad contacts between computer and mount whic I can fix just by jiggling it a bit. I think broken wire is most likely.

It wouldnt register cadence with a dead battery. I have had problems wiyh bad contacts between computer and mount whic I can fix just by jiggling it a bit. I think broken wire is most likely.

You got a point there. But what would make the odometer zero out, not a broken wire?

I also own an Astrale 8. Here's the order I'd follow:


Reset the head unit. You do this by pushing the AC (All Clear) button on the underside of the unit. You'll lose your mileage (although it sounds like that's already happened) and be forced to reselect your measurement selection and tire circumference, but this step will give you a fresh start. I had an earlier Cat Eye unit suddenly go on the fritz when it got wet one day. Pressing the AC button brought it back to life. While you're at it, clean the contact points on both the bracket and head unit.
Check the gap between the sensor and the magnet. It should be equal to or less than 5 mm.
Check the alignment of the sensor and the magnet. The marked line on the sensor should align with the center of the magnet.
Check to see if you've cut the wire.


Good luck

The sensor was too far from the magnet. It seems to work now but every once in a while the speed is incorrect so I think it is probably still too far - could easily still be more than 5 mm away from the magnet. Does it matter if I slide the sensor and the magnet closer to the hub in an effort to get the magnet and sensor closer together. I don't think it will mess with the accuracy because from what I can tell the speed is calculated based on the number of times the wheel goes around and not the distance the magnet travels in a revolution.

Thanks for your help.

The sensor was too far from the magnet. Does it matter if I slide the sensor and the magnet closer to the hub in an effort to get the magnet and sensor closer together. I don't think it will mess with the accuracy because from what I can tell the speed is calculated based on the number of times the wheel goes around and not the distance the magnet travels in a revolution.

Thanks for your help.

Slide away. You're right, it doesn't matter. There may be a slight advantage to having the magnet closer to the hub because this put the magnet adjacent to the sensor for a longer time, but I doubt that it makes any real difference.

Al