Big Blue Monster Arrives with erratic computer
 

My trike was ready on Friday (upgrade from Large to XL) so I went to the "not so LBS" to pick it up. I rode it around campus on Friday and had a blast except for one big no no! Having a foot slip off can be dangerous. If it hits the ground, you can run over your own leg. It happened to me, but I managed to lift my leg before it was sucked under the frame--mild sprain that didn't keep me off of it yesterday.

2 7 or so mile rides later, and I can report: It's damn fun! It handles well, but I can tell that it's not hard to imagine flipping it at speed. Body english is important in high speed turns.

Speed is still tough to judge, the PlanetBike 8.0 computer is going totally erratic on me. I've aligned the magnet to one of the sensor heads, adjusted the distance to magnet, pulled out hair, etc. When I get over 16 mph, the readings will start to oscillate to a low speed, then a high speed, and all over the place. Of course, it's a 35 mile drive to the trike bike shop, and I'm just trying to work it out myself.

Any tips?

Maybe the battery is toast....

Okay it's a wired computer. so it's not RFI, check the wheel size setting, this could be wrong, and it's not getting the right info. It might also be that the magnet is at the outside of the trigger range, so sometimes it catches and sometimes it doesn't. Sometimes even a new computer has a battery at the end of it's life. Lots of stuff can affect the battery, heat and cold, where it sits on the shelf, the unit at the front tends to get activated often, if the shop doesn't sell many of these units, that unit could have a flat battery. Heck much of this stuff comes from China, and the 3 month ocean voyage means the battery is already old.

I've had better luck mounting the magnet closer to the hub. Also, check out Sheldon's advice:

http://sheldonbrown.com/cyclecomputers/index.html

When adjusting the magnet distance on the $10 speedometers, they either work or don't, or that's my experience- not erratic.

You might check wheel bearings. If they have some slop, the wheel might lean one way and make it work and lean the other and be too far.

I have tried all... no luck. :( I am down to returning for a new sensor.

Problem was resolved. I called Planet Bike this morning and was greeted by a person! He quickly asked me the normal questions and was stumped. I asked him if the sensor could be mounted parallel to the ground (the not so LBS said it should be perpendicular as if on a fork), and he quickly determined any orientation was fine.

It turns out the PB sensors have two contact points... aligning the magnets with either is great, but if you get readings on both, it's bad. By turning the sensor 90 degrees and using some unconventional engineering to hold it in place, the system works like a champ. I just never could get things lined up so that only one of the sensors would fire at high speeds on the 20 inch wheel.

Another one of those weird things that us bent and trike riders deal with all of the time. :thumb: