anyone else with VDO C3DS cyclecomputer ?

Nigel Cliffe said:

I bought a VDO C3DS (wireless) cycle computer about a month back. Nice
interface, find it easier to use than Cateye models and has a couple of
other tricks I like (I've used Mity-3's for years).

But, it keeps stopping working. Frequently, if I get above about 33kph, the
transmitter appears to stop working. A minute or two later its working
again (and I've slowed down), but the device has missed the last few hundred
metres of journey (I've checked, it doesn't recover the distance).

Anyone else experiencing the same ?

I've tried moving the sensor on the forks. I've checked the magnet-sensor
distance (4mm, manual quotes a range either 1-6mm or 3-10mm depending which
page you read).
The distance between sensor and computer is well under the maximum range.
There are no other electrical devices on the bike (cellphone, lights, GPS,
etc..).

Is there a clear path from the transmitter to the receiver?

Quoted message said:

I'm going to take it back to the shop who supplied it, but I am interested
as to whether the problem is widespread or a one-off. That will help decide
whether to seek an identical replacement or refund.

Did the shop which supplied it have a dozen or so in a glass display
cabinet? If they've been there for a few years[1], the battery may be a
bit flat such that when it has the extra load of lots of transmissions
at high speed it can't cope.

[1]Since the great VDO stock up of 2003!
--

JimP

"Out of the work comes the work" - John Cage

Jim Price said:

Nigel Cliffe said:

I bought a VDO C3DS (wireless) cycle computer about a month back. Nice
interface, find it easier to use than Cateye models and has a
couple of other tricks I like (I've used Mity-3's for years).

But, it keeps stopping working. Frequently, if I get above about
33kph, the transmitter appears to stop working. A minute or two
later its working again (and I've slowed down), but the device has
missed the last few hundred metres of journey (I've checked, it
doesn't recover the distance). Anyone else experiencing the same ?

I've tried moving the sensor on the forks. I've checked the
magnet-sensor distance (4mm, manual quotes a range either 1-6mm or
3-10mm depending which page you read).
The distance between sensor and computer is well under the maximum
range. There are no other electrical devices on the bike (cellphone,
lights, GPS, etc..).

Is there a clear path from the transmitter to the receiver?

Pretty clear, and fewer obstructions than many bikes.
Its a drop-bar audax bike. Carbon fork, Shimano dual pivot brakes. Have
tried both front of fork and behind fork. Computer mounts on stem (using
standard mount).

Clearest path is half-way down fork, with transmitter ahead of fork. This is
fine, except its pretty easy to nudge the transmitter round the fork a
fraction when loading bike into car (with front wheel removed).

Slightly less clear path is low down the fork, with transmitter behind and
resting against the mudguard stays. The stays stop the transmitter being
nudged, and ensures it is 4mm clearance from magnet. I prefer this
arrangement.

Quoted message said:

Quoted message said:

I'm going to take it back to the shop who supplied it, but I am
interested as to whether the problem is widespread or a one-off. That
will help decide whether to seek an identical replacement or
refund.

Did the shop which supplied it have a dozen or so in a glass display
cabinet?

Yes, nice VDO display cabinet. Shop keeper implied it was a new design of
computer, certainly newer than 2003.

Quoted message said:

If they've been there for a few years[1], the battery may be
a bit flat such that when it has the extra load of lots of
transmissions at high speed it can't cope.

Interesting theory, I may see if the shop thinks this is the case and offers
me a new battery to test the theory.

I'm not inclined to purchase new batteries myself at this stage for
experiments - I feel a £36 gadget ought to work out of the box and for a lot
further than 300km.

- Nigel

--
Nigel Cliffe,
Webmaster at http://www.2mm.org.uk/

Nigel Cliffe said:

Jim Price said:

Nigel Cliffe wrote:
Did the shop which supplied it have a dozen or so in a glass display
cabinet?

Yes, nice VDO display cabinet. Shop keeper implied it was a new
design of computer, certainly newer than 2003.

Quoted message said:

If they've been there for a few years[1], the battery may be
a bit flat such that when it has the extra load of lots of
transmissions at high speed it can't cope.

I've just looked up the EU conformity certificate on VDO's website. That
says July 2005, which I interpret as when the device was first made
available.

--
Nigel Cliffe,
Webmaster at http://www.2mm.org.uk/

Nigel Cliffe said:

I bought a VDO C3DS (wireless) cycle computer about a month back.
Nice interface, find it easier to use than Cateye models and has a
couple of other tricks I like (I've used Mity-3's for years).

But, it keeps stopping working. Frequently, if I get above about
33kph, the transmitter appears to stop working.

Try mounting the magnet and sensor as low down as possible. The magnet
will pass more slowly when it's nearer the axle, giving the sensor more of
a chance to work.

~PB

Pete Biggs said:

Nigel Cliffe said:

I bought a VDO C3DS (wireless) cycle computer about a month back.
Nice interface, find it easier to use than Cateye models and has a
couple of other tricks I like (I've used Mity-3's for years).

But, it keeps stopping working. Frequently, if I get above about
33kph, the transmitter appears to stop working.

Try mounting the magnet and sensor as low down as possible. The
magnet will pass more slowly when it's nearer the axle, giving the
sensor more of a chance to work.

Thanks for the suggestion, I have already tried it.

It's my preferred mounting place; near bottom of fork just behind the
mudguard stays. Minimal visual intrusion and maxium protection against
accidental knocks on the sensor.

(Its also where the Cateye corded units are mounted on the three other bikes
in the house with computers).

- Nigel

--
Nigel Cliffe,
Webmaster at http://www.2mm.org.uk/

Pete Biggs said:

Nigel Cliffe said:

I bought a VDO C3DS (wireless) cycle computer about a month back.
Nice interface, find it easier to use than Cateye models and has a
couple of other tricks I like (I've used Mity-3's for years).

Try mounting the magnet and sensor as low down as possible. The magnet
will pass more slowly when it's nearer the axle, giving the sensor more of
a chance to work.

On a wireless computer you need the sensor as high up as possible to
minimise the distance from sensor to computer. The sensor has quite a
short wireless range.

--
Tony

"Anyone who conducts an argument by appealing to authority is not using
his intelligence; he is just using his memory."
- Leonardo da Vinci

Tony Raven said:

Quoted message said:

Try mounting the magnet and sensor as low down as possible. The
magnet will pass more slowly when it's nearer the axle, giving the
sensor more of a chance to work.

On a wireless computer you need the sensor as high up as possible to
minimise the distance from sensor to computer. The sensor has quite a
short wireless range.

I meant as low down as possible within the transmission range, but if
that's not low at all then it confirms my view that wireless computers
aren't worth bothering with.

~PB

Tony Raven said:

Pete Biggs said:

Nigel Cliffe said:

I bought a VDO C3DS (wireless) cycle computer about a month back.
Nice interface, find it easier to use than Cateye models and has a
couple of other tricks I like (I've used Mity-3's for years).

Try mounting the magnet and sensor as low down as possible. The
magnet will pass more slowly when it's nearer the axle, giving the
sensor more of a chance to work.

On a wireless computer you need the sensor as high up as possible to
minimise the distance from sensor to computer. The sensor has quite a
short wireless range.

Tried that as well. FWIW, the makers say 1.5m range, which would permit
rear wheel mounting for example (contrasting with Cateye's claimed 70cm).
None of the mounting places on the front of my bike are over 65cm range.

Keep the suggestions coming, but I think its heading for "refund as not fit
for purpose".

- Nigel

--
Nigel Cliffe,
Webmaster at http://www.2mm.org.uk/

Nigel Cliffe said:

Keep the suggestions coming, but I think its heading for "refund as
not fit for purpose".

I'm scraping the barrel now, but how about a more powerful magnet?

~PB

Pete Biggs said:

Nigel Cliffe said:

Keep the suggestions coming, but I think its heading for "refund as
not fit for purpose".

I'm scraping the barrel now, but how about a more powerful magnet?

I appreciate the thoughts and attempts at solution.

The receiver is 4mm from the magnet (3.73mm according to a digital slide
gauge), magnet square across the mark on the transmitter for alignment (and
its the one supplied). The instructions quote 1-6mm in one place, and
3-10mm clearance in another. Therefore I'm in the specification range (even
the worst case of 3-6mm).

I don't see 33kph (where it stops reading) as fast. Most regular touring
cyclists will regularly exceed 40kph on decents, and occaisional 60kph isn't
that unusual. Racers will go faster still.

The notion of magnet speed which would be reduced by putting the transmitter
nearer the hub doesn't seem to make a huge difference; yet the magnet speed
would drop by 1/3 between the two mounting points I've tried.

I'll try to call at the shop later today. I'm inclined to seek refund on
the wireless model and then purchase the wired version.

- Nigel

--
Nigel Cliffe,
Webmaster at http://www.2mm.org.uk/

Nigel Cliffe said:

I bought a VDO C3DS (wireless) cycle computer about a month back. Nice
interface, find it easier to use than Cateye models and has a
couple of other tricks I like (I've used Mity-3's for years).

But, it keeps stopping working. Frequently, if I get above about
33kph, the transmitter appears to stop working. A minute or two
later its working again (and I've slowed down), but the device has
missed the last few hundred metres of journey (I've checked, it
doesn't recover the distance).
Anyone else experiencing the same ?

I went back to the shop today who said there is a known fault on some, but
not all, of them, and free replacement without question. The symptoms I saw
(failing at 30-something kph) is known. They have 3 or 4 waiting to go back
to the suppliers.

Shop explained about change in design, the replacement has revised aerial
receiver unit on rear of computer (which can be seen in a small cylindrical
bobble sticking out below)/ The instructions have been revised , and now
insist everything is mounted on LH side of bike (aligning with the bobble).

The makers have also gone back to a default handle-bar mount rather than
stem mount, however shop swapped the mounts between the faulty and new one
so I can continue to use the stem. Stem mount is still shown as
spare/upgrade part, and is referred to in the (revised) instructions as an
optional extra.

Preliminary test (two sprints down local road getting to 37kph and 39kph)
suggest that the initial fault has gone away. Longer test to be carried out
when I've the time to head out on a few rides.

So, that appears to be the answer. If it doesn't fix the problem I'll post
again, but a few weeks test is now in order.

Price has also crept up, were I shopping now, I'd find the extra £7 (£42 vs
£35) unnacceptable against the price of Cateye units or corded models.
(Though obviously, as a faulty product return, I was not charged the extra.)

- Nigel

--
Nigel Cliffe,
Webmaster at http://www.2mm.org.uk/