Batty Halfords spedo....

I remember swapping a computer for a Halfords cheapy, putting a new sensor
on the spokes and getting the same result, ie double the speed. Turned out,
I'd forgotten to remove the old sensor.......

"LaoFuZhi" <the.real.address [email hidden]
thing.not.too.hard.to.work.out> wrote in message
news:[email hidden]...

Quoted message said:

After much nagging I fitted one of the little halfords 8 function

computers

Quoted message said:

to the Mrs' bike.......

It's got 26X20 wheels so I duly dialled in 2099mm as per the
instructions..... And she took it for a wee spin 'round the local

park....

Quoted message said:

The thing seems to be reporting roughly double the actual speed!

I've fitted dozens of cycle computers over the years and am reasonably

sure

Quoted message said:

the sensor\magnet is fitted correctly... It IS set to MPH.... I worked
around it by dialling in 1100 but it's still a tad high....

Anyone got any idea why this thing seems to be giving strange results

(apart

Quoted message said:

from being a cheap nasty P.O.S!)

"Fil" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I remember swapping a computer for a Halfords cheapy, putting a new sensor
on the spokes and getting the same result, ie double the speed. Turned

out,

Quoted message said:

I'd forgotten to remove the old sensor.......

:-) Hmmmmm, easy done I suppose...... But this bike has never had a spedo
before...

In my justification, I have several bikes and am always tinkering. Still a
bit thick though. As a thought, check that the centre of your spoke mounted
circular sensor is aligned to either the top or the bottom of the lozenge
shaped forked sensor - if you look closely, you'll see there's two ridges
corresponding to an upper and lower sensor - and not in the middle. That can
also give a mis-reading.

"LaoFuZhi" <the.real.address [email hidden]
thing.not.too.hard.to.work.out> wrote in message
news:[email hidden]...

Quoted message said:

"Fil" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I remember swapping a computer for a Halfords cheapy, putting a new

sensor

Quoted message said:

Quoted message said:

on the spokes and getting the same result, ie double the speed. Turned

out,

Quoted message said:

I'd forgotten to remove the old sensor.......

:-) Hmmmmm, easy done I suppose...... But this bike has never had a spedo
before...

It's either knackered or it's reading in KPH not MPH

Rgds, Bob

"LaoFuZhi" <the.real.address [email hidden]
thing.not.too.hard.to.work.out> wrote in message
news:[email hidden]...

Quoted message said:

After much nagging I fitted one of the little halfords 8 function

computers

Quoted message said:

to the Mrs' bike.......

It's got 26X20 wheels so I duly dialled in 2099mm as per the
instructions..... And she took it for a wee spin 'round the local

park....

Quoted message said:

The thing seems to be reporting roughly double the actual speed!

I've fitted dozens of cycle computers over the years and am reasonably

sure

Quoted message said:

the sensor\magnet is fitted correctly... It IS set to MPH.... I worked
around it by dialling in 1100 but it's still a tad high....

Anyone got any idea why this thing seems to be giving strange results

(apart

Quoted message said:

from being a cheap nasty P.O.S!)

On Sun, 18 Jul 2004 19:33:42 +0000 (UTC), "LaoFuZhi" <the.real.address
[email hidden] thing.not.too.hard.to.work.out>

Quoted message said:

After much nagging I fitted one of the little halfords 8 function computers
to the Mrs' bike.......

It's got 26X20 wheels so I duly dialled in 2099mm as per the
instructions..... And she took it for a wee spin 'round the local park....
The thing seems to be reporting roughly double the actual speed!

I've fitted dozens of cycle computers over the years and am reasonably sure
the sensor\magnet is fitted correctly... It IS set to MPH.... I worked
around it by dialling in 1100 but it's still a tad high....

Anyone got any idea why this thing seems to be giving strange results (apart
from being a cheap nasty P.O.S!)

Just guessing wildly here: you could try and adjust (increase?) the
distance between the magnet and sensor, by moving them both further to
the outside of the wheel. Maybe when the magnet is too close it
doesn't detect it, so you get a double contact for each actual pass of
the magnet.

It could also be that it is expecting the diameter rather than
circumference, is it possibly out by a factor of 3(.14) rather than 2?

--
Jeremy

LaoFuZhi said:

It's got 26X20 wheels so I duly dialled in 2099mm as per the
instructions..... And she took it for a wee spin 'round the local
park.... The thing seems to be reporting roughly double the actual
speed!

Swivel the sensor a bit further outwards. I bet it's picking up the
magnet twice per rev.

Quoted message said:

I've fitted dozens of cycle computers over the years and am
reasonably sure the sensor\magnet is fitted correctly...

I've fitted loads as well and find some trial & error is needed sometimes.

~PB

Quoted message said:

- if you look closely, you'll see there's two ridges
corresponding to an upper and lower sensor - and not in the middle. That

can

Quoted message said:

also give a mis-reading.

Quoted message said:

It's either knackered or it's reading in KPH not MPH

Knackered seems to be the best guess so far...... The sensor Is properly
aligned and set for MPH....

Then take it back and spend a few squid more. Halfords' stock VDO and
Cateye. I doubt you'll have a problem with them, even their cheaper ranges.

"LaoFuZhi" <the.real.address [email hidden]
thing.not.too.hard.to.work.out> wrote in message
news:[email hidden]...

Quoted message said:

Quoted message said:

- if you look closely, you'll see there's two ridges
corresponding to an upper and lower sensor - and not in the middle. That

can

Quoted message said:

also give a mis-reading.

Quoted message said:

It's either knackered or it's reading in KPH not MPH

Knackered seems to be the best guess so far...... The sensor Is properly
aligned and set for MPH....

Quoted message said:

Then take it back and spend a few squid more. Halfords' stock VDO and

Hmmm, yes I suppose..... If I can be bothered.... If she cycled seriously
I'd have bought a decent one inthe first place....

Fil said:

Then take it back and spend a few squid more. Halfords' stock VDO and
Cateye. I doubt you'll have a problem with them, even their cheaper
ranges.

You can have the same problem with a Cateye if the sensor is too near the
magnet. Give it a chance.

~PB

Quoted message said:

Swivel the sensor a bit further outwards. I bet it's picking up the
magnet twice per rev.

I'll do just that in the morning.... Thanks for the suggestion folks; now I
think about it these sensors are generally just a little reed switch that
could bounce in too strong a field....

"LaoFuZhi" <the.real.address [email hidden]
thing.not.too.hard.to.work.out> wrote in message
news:[email hidden]...

Quoted message said:

After much nagging I fitted one of the little halfords 8 function

computers

Quoted message said:

to the Mrs' bike.......

It's got 26X20 wheels so I duly dialled in 2099mm as per the
instructions..... And she took it for a wee spin 'round the local

park....

Quoted message said:

The thing seems to be reporting roughly double the actual speed!

I've fitted dozens of cycle computers over the years and am reasonably

sure

Quoted message said:

the sensor\magnet is fitted correctly... It IS set to MPH.... I worked
around it by dialling in 1100 but it's still a tad high....

Anyone got any idea why this thing seems to be giving strange results

(apart

Quoted message said:

from being a cheap nasty P.O.S!)

Did you take the old magnet from the previous 'puter off?

T

Quoted message said:

Did you take the old magnet from the previous 'puter off?

It never had one..... It's my wife's bike; she hardly ever uses it, but got
the notion into her head she 'needs' a speedo.....

in message <[email hidden]>, LaoFuZhi
('the.real.address [email hidden]

thing.not.too.hard.to.work.out') said:

It's got 26X20 wheels so I duly dialled in 2099mm as per the
instructions..... And she took it for a wee spin 'round the local
park.... The thing seems to be reporting roughly double the actual
speed!

Anyone got any idea why this thing seems to be giving strange results
(apart from being a cheap nasty P.O.S!)

Two magnets on the wheel?

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; 'I think we should trust our president in every decision
;; that he makes and we should just support that'
;; Britney Spears of George W Bush, CNN 04:09:03

LaoFuZhi said:

It never had one..... It's my wife's bike; she hardly ever uses it, but got
the notion into her head she 'needs' a speedo.....

Does she plan to visit Richmond Park?

Colin McKenzie

--
The great advantage of not trusting statistics is that
it leaves you free to believe the damned lies instead!

Quoted message said:

Two magnets on the wheel?

Nope.... somebody else suggested that.....

LaoFuZhi said:

Quoted message said:

Then take it back and spend a few squid more. Halfords' stock VDO and

Hmmm, yes I suppose..... If I can be bothered.... If she cycled seriously
I'd have bought a decent one inthe first place....

Well, you never know, her asking for one might mean she's thinking about
doing it a bit more seriously, or you might find that if she can see
what speed she does, she might start upping the speed a bit, and if she
carries on with that, she might be bitten by the bug ;-)

I got a very nice bike, got a computer, and even from the outset where I
was most definitely NOT an addict, I was curious about the speeds and
distances, and every time a ride was a bit faster, it was encouraging.
Probably one of the little things that balanced out the bad bits, if I'm
honest.

So don't discount it completely as a sign of good things to come ;-)

If you're interested, I have a cateye astrale here that I no longer use
(was only on there for use on my turbo, rear wheel + cadence sensor
fittings, wires, not wireless). Not sure what they retail at, you might
have to be a bit creative when it comes to attaching the sensor holding
bands, since they've been snipped to fit my bike's tube diameters etc,
but all the bits are there and in working order, make me an offer and
maybe she can have a good but relatively cheap cycling computer, that
way it wouldn't matter so much if she doesn't actually use it?

--

Velvet

Quoted message said:

Well, you never know, her asking for one might mean she's thinking about
doing it a bit more seriously, or you might find that if she can see
what speed she does, she might start upping the speed a bit, and if she
carries on with that, she might be bitten by the bug ;-)

Ah! if only...... She's had the bike a little over two years; I bought it
for her 31st and at that point she actually had to learn to ride having
never had a bike in her life before!!.... At first I thought she was going
to get into it; but the notion only lasted about three months. It comes out
the cupboard occasionally when the sun's shining; And then she rushes off to
Halfords to buy another gadget for it.... NOw and again she rides it to the
next village.... I followed her out on it last night to test this spedo
accompanied by out 7-Y/O daughter who was literally riding circles 'round
her ....don't think I can book that cycling tour of Southern France _quite_
yet ;-) though if she's getting some exercise some time that can't be a bad
thing...

Quoted message said:

So don't discount it completely as a sign of good things to come ;-)

Oh, I'm not...... Let's just say I'm a touch guarded.... It's like the
stepper, and the wheelie thing with handles; last night she was sitting up
in bed ready to order another daft over-priced stepper thingie from qvc or
somewhere....

Quoted message said:

If you're interested, I have a cateye astrale here that I no longer use
(was only on there for use on my turbo, rear wheel + cadence sensor
fittings, wires, not wireless).

The offer's appreciated... As I'm building another bike for myself I may
come back to you on that one....

Quoted message said:

Does she plan to visit Richmond Park?

Not unless she's on a bus trip AFAIK...... ;-)