Computer exaggerating top speed

[AL_BUNDY]

I have a Planet bike Protege 9.0. I use it on 2 bikes. On the recumbent trike it works perfect but on my mountain bike it exaggerates the top speed by roughly double and triple. The other functions Distance, average speed, and present speed appear to be ok but not 100% sure about that either. At one point I noticed an error message as riding but it quickly self corrected. After that I moved the pick up from the front of the fork to the rear thinking the brakes were blocking the signal causing weird readings. I then went for a 15 mile ride and either hit a top speed of 77mph or its still messed up. Here are a few pictures of the mounting.

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[AndrewB]

In the first picture, is that silver thing just obscured by the fork the magnet on the spoke?

After downloading the instructions from Planet Bike's site at http://planetbike.com/files/8003manual.pdf , you might want to look at step 2 and step 3's images. I'm not sure what they mean by "DO NOT line up Magnet between GLOSSY LINES on Sensor" means, but in the step 2 image, the magnet looks like it hits the protruding bump on the sensor.

I also believe you might have the sensor turned about 90 degrees to the left, or thereabouts. My guess would be that the Planet Bike logo would be parallel to forward. It's hard to tell from your pics and looking at the docs, but take another look at them, the rotation of the sensor, and the placement of the magnet.

The instructions state that you need 2mm of clearance space between the sensor and the magnet. If you can't get that distance where the sensor is currently mounted, try moving the sensor lower on the fork. Closer to the center of the wheel, the spokes are closer to the fork than they are where they enter the rim.

My Cateye Strada magnet is mounted about 1 7/8" from the center.

AndrewB

[JohnV]

Since the wheels on this bike are 26" and the ones on your Tadpole are 20", I am assuming that the problem occurs after you change the setting for the wheel size from bike to bike, correct? If true, and it does it on both bikes, then you may have a faulty sensor/transmitter. I see that the computer is wireless. You could have some radio interference along your route or some magnetic interference from something on your bike. I have heard from other riders that have wireless computers that their cell phones have given them problems with the computers. I hear about so many issues with wireless computers from people I ride with and pretty much nothing about wired and that's the reason why I use wired.

[dave_sd]

Is it wireless? All the wireless computers I've used love to pick up interference from power lines and they show top speeds around 70 mph. Haven't had any problems with my gps computers yet.

[AL_BUNDY]

(06-18-2011, 11:23 PM)dave_sd Wrote:  Is it wireless? All the wireless computers I've used love to pick up interference from power lines and they show top speeds around 70 mph. Haven't had any problems with my gps computers yet.

I think you hit it. I rarely ride the trike into town. I wanted to take the Pup tonight so I took the trike same route I take the MTB. I dont think at any point the Pup ran 50mph. Im thinking there is one of those big electrical boxes along the bike path. I will try to pay more attention next time.
Thanks Every one
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[JohnV]

So, after saying that I use nothing but wired, my wife bought herself a new recumbent trike yesterday and the only computer that would work on it is a wireless. So, I guess she will have to start watching out for all the little issues with these things.

Al,

Can I ask where you got the bottle cage from? The only one on my wife's new tadpole is on the rear or the seat and I was trying to find a way to mount one in an area where she can reach it better.

[AL_BUNDY]

Thats just a standard Bontrager cage. There are threaded braze-ons located on my derailleur post.
Here is a good supplier http://poweroncycling.com/ and here is one option http://poweroncycling.com/product-list/hydration-1025/cage-mounting-hardware-1087/
Here are a couple other cages http://poweroncycling.com/product-list/hydration-1025/cages-1088/

[AndrewB]

AL_BUNDY, did you see my initial reply on this thread? I think you have the sensor installed incorrectly on the bike after looking at the instructions. Isn't that circular bump the actual sensor? If it is, you have it pointed forward on the mountain bike, and upward (sky) on the red bike. From the instructions, it appears the sensor should be pointed to the magnet on the spoke, and within 2 mm.

[JohnV]

So, that's just a standard tube clamp-on mount that the cage is on? I couldn't really tell as the mount looked as if it were part of the tube cap.

Another thing I found about these wireless computers on tadpole recumbents. Putting the sensor on the rear wheel and the computer head on the mounting bracket doesn't work. They are too far apart so now I have to figure out how to mount the computer head so that it picks up the signal. I looked at the way you did it, but on her tadpole the disk brake mount doesn't have anywhere that I can mount a bar as you did on yours.

[AL_BUNDY]

No there are factory threaded studs already there for a water bottle on my trike. But a clamp on should work if yours dont. I used the caliper bolts to mount my bar fo the sensor.
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[AL_BUNDY]

(06-19-2011, 12:16 PM)AndrewB Wrote:  AL_BUNDY, did you see my initial reply on this thread? I think you have the sensor installed incorrectly on the bike after looking at the instructions. Isn't that circular bump the actual sensor? If it is, you have it pointed forward on the mountain bike, and upward (sky) on the red bike. From the instructions, it appears the sensor should be pointed to the magnet on the spoke, and within 2 mm.

I did. That bump is the battery. The instruction that came with it were more vague. You would think they would match what is on the sight. Im guessing I bought an older unit that the instructions have since been updated(ebay). I have had it on the trike a long time with no problems so I thought leave well enough alone. Then last night I rode the path I usually ride the MTB and the trike messed up for the 1st time. There is another side to the story also. The receiver is new. I broke the original and ordered a whole new computer (ebay again). So now I had an extra mount/sensor and decided to put that on the MTB.

[AL_BUNDY]

(06-19-2011, 12:16 PM)AndrewB Wrote:  AL_BUNDY, did you see my initial reply on this thread? I think you have the sensor installed incorrectly on the bike after looking at the instructions. Isn't that circular bump the actual sensor? If it is, you have it pointed forward on the mountain bike, and upward (sky) on the red bike. From the instructions, it appears the sensor should be pointed to the magnet on the spoke, and within 2 mm.

I found the instructions that came with the new unit. They matched the online instructions. I repositioned them so time will tell.