77mph ... in Kensington?

bice

I have fitted up an Atech F13 bike computer (£18 approx). Most of its readings seem plausible. I even think I did do 40mph down a hill in Wales over Christmas.

But last week the max speed indicator said I did 77mph coming from Kensington to Wandsworth Common. This is obviously cobblers. The leaflet says atmospheric conditions and interference can give 'misleading' results.

It's worse when it is more plausible: I did Richmond Park on Sunday (clockwise) and have it recorded that I did 39.7mph, when I dont think the speed went above 30mph.

All the other recordings given seem plausible and accurate.

Is this a common problem with these devices? If they are recording nonsense, you want it to be complete nonsense.

Headhuunter

In my experience, once set up correctly, readings are pretty accurate and consistent. Perhaps the cold is affecting it? Cold can certainly affect battery power

Not Another Hill

I've had 84 mph top speed on a club run a few weeks ago and a trip distance of 845 miles. Pretty good I thought. Never false readings before. I put it down to the battery being ffected by the cold weather.

ademort

I once had a cateye computer which went the same way. During one paricular ride the computer started fluctuating between 30 and 50 Km/h. I came to a stop at the railway line crossing and my computer was showing my current speed to be 99Km/h.Got home changed the battery and the computer functioned normally again.
Ademort

redvee

Put a new battery into my Lidl special recently but not had chance to test it against the traffic light sensors/bluetooth devices in cars or the security barriers in Cabot circus. these are known to give me a 53.9 mph speed when sat oustide waiting for a friend looking at the bargains in Zavvi.

Blonde

Sometimes the battery in the sensor dies and needs to be replaced - though this usually results in a stuck speed reading (speed reading does not change even though you are clearly speeding up or slowing down).

Check the contacts for corrosion or tarnished appearance - a light sanding with an emery board or glass paper/sand paper will restore a good connection.

rb1956

My speedo readings seem pretty reasonable, but my cadence sensor sometimes delivers crazy readings like 175 rpm.

Bodhbh

I had a problem with mine 'sticking' for a good few seconds with the reading (ie not going up or down when accelerating or stopping). Also I figured the reading was 5 or so mph out at times. Like you say, it's more annoying when it's close and giving false but plausible results. I had a large D-lock in the front pannier which I suspect might have effected the magnet, but really have no idea otherwise, problem seemed to fix itself.

Bodhbh

Bodhbh wrote:

I had a large D-lock in the front pannier which I suspect might have effected the magnet, but really have no idea otherwise, problem seemed to fix itself.

Doh forks already steel, engage brain. :roll:

Chocolatebike

The speed display on my Polar HRM is sometimes affected by cars and buses.
I remember passing a BMW 6 Series (it was going in the other direction, I didn't overtake it !) and my speed jumped from 31mph to 49mph then straight back down gain.
Unfortunately that speed was then lodged in the computer memory for the rest of the year.

chronyx

I once had a maximum speed out 78mph out of a Falcon Stealth MTB at the ago 12 apparently

Tranced

Often have the MAX speed go haywire on various computers. I now try to memorise MAX when I feel I'm hoofing it for my ride logs incase the comp goes wobbly.

knackeredknees

bice wrote:

I have fitted up an Atech F13 bike computer (£18 approx). Most of its readings seem plausible. I even think I did do 40mph down a hill in Wales over Christmas.

But last week the max speed indicator said I did 77mph coming from Kensington to Wandsworth Common. This is obviously cobblers. The leaflet says atmospheric conditions and interference can give 'misleading' results.

I have the same computer and it has registered my maximum speed now for about 2 years as 77mph! I seem to remember that C+ had the same problem with theirs that they reviewed a while back. I tried resetting mine, it recorded the right max speed for about a week, then you've guessed it, it went to 77mph!

Mettan

redvee wrote:

but not had chance to test it against the traffic light sensors/bluetooth devices in cars

I get this aswell with my cheap Wireless one - going past certain traffic lights (or similar) mine might jump up from say 20 to 50 - only lasts a few seconds or so and then it comes back down to normal.

spursn17

I used to get this with my old wireless Cateye with a magnetic sensor. I noticed it went potty when a lorry (usually a tipper) came close as it passed me.

Not had any problems since using a Garmin 205.