Inflated wireless readouts

[Ben Barker]

I've had a cateye wireless computer (cordless 7, from the pictures I found online ...?)on my bike
for a while now, and in general it seems fab - an improvement on its predecessor, whose sensor was
carefully designed to fall off any bike with non cylindrical forks!

Most of its readings (current speed, distance) etc are pretty obviously correct, but after any ride
my maximum speed can be anywhere from 60 to 90 mph. While I like to flatter myself, this is just
silly. Does anyone have any ideas why this might be happening? I cycle mainly in London, so there's
plenty of scope for interference, but I cant think from where.

Ben

 

[Cyclist]

> Does anyone have any ideas why this might be happening? I cycle mainly in London, so there's
> plenty of scope for interference, but I cant think from where.
>
> Ben

It's caused by magnetic traffic control loops in the road. The sensor picks up one signal from the
magnet on your spoke and then another immediately after from the loop in the road. Hence the
distortion in your speed.

Simonb

 

[Dave Larrington]

Ben Barker wrote:

> Most of its readings (current speed, distance) etc are pretty obviously correct, but after any
> ride my maximum speed can be anywhere from 60 to 90 mph. While I like to flatter myself, this is
> just silly. Does anyone have any ideas why this might be happening? I cycle mainly in London, so
> there's plenty of scope for interference, but I cant think from where.

I used to get interference with a heart rate monitor from one-man-operated buses. Every time one
overtook, the heart rate would drop to zero and remain there until it was fifty yards up the road.
Whereas my pulse rate was actually soaring, because 99% of bus drivers are idiots who have no
conception of how fast cyclists can move.

Dave Larrington - http://www.legslarry.beerdrinkers.co.uk/
===========================================================
Editor - British Human Power Club Newsletter
http://www.bhpc.org.uk/
===========================================================

 

[Richard Goodman]

"cyclist" <whatever> wrote in message news:[email protected]...
> > Does anyone have any ideas why this might be happening? I cycle mainly in London, so there's
> > plenty of scope for interference, but I cant think from where.
> >
> > Ben
>
> It's caused by magnetic traffic control loops in the road. The sensor
picks
> up one signal from the magnet on your spoke and then another immediately after from the loop in
> the road. Hence the distortion in your speed.
>

Ah, so that explains why I once recorded 72mph as I stopped at traffic lights! I thought it
was because I'd caused the wheel to rock back slightly as I stopped, just as the magnet passed
the sensor...

Rich

 

[Martin]

"Dave Larrington" <[email protected]> wrote in message
news:<[email protected]>...
> Ben Barker wrote:
>
> > Most of its readings (current speed, distance) etc are pretty obviously correct, but after any
> > ride my maximum speed can be anywhere from 60 to 90 mph. While I like to flatter myself, this is
> > just silly. Does anyone have any ideas why this might be happening? I cycle mainly in London, so
> > there's plenty of scope for interference, but I cant think from where.
>
> I used to get interference with a heart rate monitor from one-man-operated

Funny you should say that: I got 65mph coming in the back entrance to work just under the ECG unit.
Does this mean we have the same effect on this equipment when we ride past? (Mobile phones/Bicycles
to be switched off in this hospital)