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Wheel/Spoke Magnets



 
 
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  #11  
Old May 13th 19, 11:56 AM posted to rec.bicycles.tech
Sir Ridesalot
external usenet poster
 
Posts: 5,270
Default Wheel/Spoke Magnets

On Monday, May 13, 2019 at 6:47:07 AM UTC-4, John B. Slocomb wrote:
On Mon, 13 May 2019 07:06:48 +0200, Tosspot
wrote:

On 13/05/2019 01:45, John B. Slocomb wrote:
On Sun, 12 May 2019 16:26:11 -0700, "Mark J."
wrote:

On 5/12/2019 6:27 AM, sms wrote:
On 5/12/2019 1:29 AM, Tosspot wrote:
Anyone know of some 'decent' ones.Â* The Sigma supplied ones won't
attract a whore in a crack house.Â* The Bosch type ones always seem to
corrode and fall off, and on top of that are easy to X-Thread.Â* The
Cat-Eye ones don't seem to stay put[1].Â* The Echowell/Yamaha ones seem
pretty decent but are like rocking horse **** this side of the pond..
Any other ideas?

[1] Yes, it is getting OCD!

When I lost the cadence magnet on my crank I used a hard-drive magnet,
i.e. https://www.ebay.com/itm/173209158372 but I got some used ones
from someone I knew at a disk drive company. I heat shrinked it over the
crank. I guess for a wheel magnet you could use some cable ties or some
baling wire and attach one of these to the spokes. The pick-up doesn't
have to be so close to the magnet when you use a disk drive magnet.

If heat shrink is too much trouble, the ?vinyl? stretchy plastic
electrical tape works pretty well also, I've done this for cadence
magnets. The tape may start to peel and degenerate into a sticky mess,
but if caught/redone in time, the mess is quite containable.

Mark J.

I bonded used Hard disk magnets onto the aluminum crank arms of all of
my (4) bicycles as much as 10 years ago using epoxy glue. To date the
magnets are all still attached :-)

As to the original post, I have spoke magnets that I attached to front
wheels both with radial spokes and with crossed spokes that have been
in place for 4 - 5 years.

What is the big problems with attaching magnets to bicycles?


It isn't a problem per se. For some reason there is a *big* gap between
the spokes and the Surly LHT frame, which means at best, standard
magnets are intermittent. The fix is obvious, a small neodymium disc
magnet, but this tends to cause enough of some adverse force to cause
the above problems. In short, the Sigma ones don't cut the mustard,
different ones work ok for a year or two. I want a good magnet, that
stays put, doesn't corrode and I can't fyckup fitting.


I think that you are referring to a cycle meter pickup - spoke magnet
and sensor mounted on the front fork? What I do is mount the magnet
and than mount the sensor with a bit of offset - bent in, one might
say. Works for me :-)

The indomitable Sheldon recommends installing the magnet as near the
hub as possible as it means that the magnet passes the sensor
(transmitter) slower which he feels might make things more accurate.

As an aside, it also means that the magnet is closer to the fork tube
and therefore the sensor is closer to the magnet and requires less
offset. See https://www.youtube.com/watch?v=q-eGGDFeaUM
for an example (I know it is a cabled meter but the position of the
sender is the same as a wireless sensor).

--

Cheers,

John B.


Some wireless magnets NEED to be mounted close to the rim in order to be picked up by the sensor which also needs to be as close to the actual computer unit as possible. I had a wireless computer that had intermittent readings and readings far in excess of my actual speed. Those problems were corrected when the magnet and sensor were moved as far up the wheels and fork as possible. It seems that the distance that the sensor was from the computer was a critical factor with that computer as it was a very short range from the sensor to the unit that worked.

Cheers
Ads
  #12  
Old May 13th 19, 12:02 PM posted to rec.bicycles.tech
John B. Slocomb
external usenet poster
 
Posts: 547
Default Wheel/Spoke Magnets

On Sun, 12 May 2019 17:37:12 -0700, sms
wrote:

On 5/12/2019 4:26 PM, Mark J. wrote:
On 5/12/2019 6:27 AM, sms wrote:
On 5/12/2019 1:29 AM, Tosspot wrote:
Anyone know of some 'decent' ones.* The Sigma supplied ones won't
attract a whore in a crack house.* The Bosch type ones always seem to
corrode and fall off, and on top of that are easy to X-Thread.* The
Cat-Eye ones don't seem to stay put[1].* The Echowell/Yamaha ones
seem pretty decent but are like rocking horse **** this side of the
pond. Any other ideas?

[1] Yes, it is getting OCD!

When I lost the cadence magnet on my crank I used a hard-drive magnet,
i.e. https://www.ebay.com/itm/173209158372 but I got some used ones
from someone I knew at a disk drive company. I heat shrinked it over
the crank. I guess for a wheel magnet you could use some cable ties or
some baling wire and attach one of these to the spokes. The pick-up
doesn't have to be so close to the magnet when you use a disk drive
magnet.


If heat shrink is too much trouble, the ?vinyl? stretchy plastic
electrical tape works pretty well also, I've done this for cadence
magnets.* The tape may start to peel and degenerate into a sticky mess,
but if caught/redone in time, the mess is quite containable.


I SPIT on electrical tape.


But it works so well for taping electrical splices :-)
--

Cheers,

John B.
  #13  
Old May 13th 19, 03:01 PM posted to rec.bicycles.tech
Frank Krygowski[_2_]
external usenet poster
 
Posts: 7,511
Default Wheel/Spoke Magnets

On Monday, May 13, 2019 at 6:57:02 AM UTC-4, Sir Ridesalot wrote:


Some wireless magnets NEED to be mounted close to the rim in order to be picked up by the sensor which also needs to be as close to the actual computer unit as possible. I had a wireless computer that had intermittent readings and readings far in excess of my actual speed. Those problems were corrected when the magnet and sensor were moved as far up the wheels and fork as possible. It seems that the distance that the sensor was from the computer was a critical factor with that computer as it was a very short range from the sensor to the unit that worked.


As I think I mentioned, my folding bike's wireless cyclometer lost the signal
from it's magnet and sender when the weather was cold. The small wheel diameter
meant the sender to cyclometer distance was within the unit's maximum separation
according to the manual, but just barely.

I finally solved the problem by mounting the cyclometer on a plastic stub in
front of the handlebar. It seems the handlebar itself was partially blocking
the radio signal.

- Frank Krygowski
  #14  
Old May 13th 19, 03:56 PM posted to rec.bicycles.tech
Jeff Liebermann
external usenet poster
 
Posts: 4,018
Default Wheel/Spoke Magnets

On Sun, 12 May 2019 06:27:51 -0700, sms
wrote:

On 5/12/2019 1:29 AM, Tosspot wrote:
Anyone know of some 'decent' ones.* The Sigma supplied ones won't
attract a whore in a crack house.* The Bosch type ones always seem to
corrode and fall off, and on top of that are easy to X-Thread.* The
Cat-Eye ones don't seem to stay put[1].* The Echowell/Yamaha ones seem
pretty decent but are like rocking horse **** this side of the pond. Any
other ideas?

[1] Yes, it is getting OCD!


When I lost the cadence magnet on my crank I used a hard-drive magnet,
i.e. https://www.ebay.com/itm/173209158372 but I got some used ones
from someone I knew at a disk drive company. I heat shrinked it over the
crank. I guess for a wheel magnet you could use some cable ties or some
baling wire and attach one of these to the spokes. The pick-up doesn't
have to be so close to the magnet when you use a disk drive magnet.


I tried a disk drive magnet and had problems. The typical magnet is
not a single piece of iron with a single pair of poles, but rather two
magnets with two pairs of poles:
https://physics.stackexchange.com/questions/12283/if-you-place-a-spring-on-a-neodymium-hard-drive-magnet-it-appears-to-vibrate-in
By adjusting the position and orientation, it worked quite well.
However, if the magnet moved, I would get erratic operation. I got my
best resuls by breaking a magnet in half, resulting in (mostly) one
pair of poles. I don't recall which brand of bicycle computah I used,
but I think it may have been a Sigma.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #15  
Old May 13th 19, 04:16 PM posted to rec.bicycles.tech
SMS
external usenet poster
 
Posts: 9,477
Default Wheel/Spoke Magnets

On 5/12/2019 10:06 PM, Tosspot wrote:

snip

It isn't a problem per se.Â* For some reason there is a *big* gap between
the spokes and the Surly LHT frame, which means at best, standard
magnets are intermittent.Â* The fix is obvious, a small neodymium disc
magnet, but this tends to cause enough of some adverse force to cause
the above problems.Â* In short, the Sigma ones don't cut the mustard,
different ones work ok for a year or two.Â* I want a good magnet, that
stays put, doesn't corrode and I can't fyckup fitting.


I think that a disk drive magnet, covered with heat-shrink tubing to
prevent corrosion, and attacked to the spokes through the holes on the
mount, would work. A bit heavy though.


  #16  
Old May 13th 19, 05:07 PM posted to rec.bicycles.tech
Mark J.
external usenet poster
 
Posts: 840
Default Wheel/Spoke Magnets

On 5/12/2019 5:37 PM, sms wrote:
On 5/12/2019 4:26 PM, Mark J. wrote:
On 5/12/2019 6:27 AM, sms wrote:
On 5/12/2019 1:29 AM, Tosspot wrote:
Anyone know of some 'decent' ones.Â* The Sigma supplied ones won't
attract a whore in a crack house.Â* The Bosch type ones always seem
to corrode and fall off, and on top of that are easy to X-Thread.
The Cat-Eye ones don't seem to stay put[1].Â* The Echowell/Yamaha
ones seem pretty decent but are like rocking horse **** this side of
the pond. Any other ideas?

[1] Yes, it is getting OCD!

When I lost the cadence magnet on my crank I used a hard-drive
magnet, i.e. https://www.ebay.com/itm/173209158372 but I got some
used ones from someone I knew at a disk drive company. I heat
shrinked it over the crank. I guess for a wheel magnet you could use
some cable ties or some baling wire and attach one of these to the
spokes. The pick-up doesn't have to be so close to the magnet when
you use a disk drive magnet.


If heat shrink is too much trouble, the ?vinyl? stretchy plastic
electrical tape works pretty well also, I've done this for cadence
magnets.Â* The tape may start to peel and degenerate into a sticky
mess, but if caught/redone in time, the mess is quite containable.


I SPIT on electrical tape.


The gummy adhesive is a pain, yes, but saliva is not a suitable solvent
for cleaning it.

Mark J.
  #17  
Old May 13th 19, 07:52 PM posted to rec.bicycles.tech
Tosspot[_3_]
external usenet poster
 
Posts: 1,563
Default Wheel/Spoke Magnets

On 13/05/2019 02:37, sms wrote:
On 5/12/2019 4:26 PM, Mark J. wrote:
On 5/12/2019 6:27 AM, sms wrote:
On 5/12/2019 1:29 AM, Tosspot wrote:
Anyone know of some 'decent' ones. The Sigma supplied ones
won't attract a whore in a crack house. The Bosch type ones
always seem to corrode and fall off, and on top of that are
easy to X-Thread. The Cat-Eye ones don't seem to stay put[1].
The Echowell/Yamaha ones seem pretty decent but are like
rocking horse **** this side of the pond. Any other ideas?

[1] Yes, it is getting OCD!

When I lost the cadence magnet on my crank I used a hard-drive
magnet, i.e. https://www.ebay.com/itm/173209158372 but I got
some used ones from someone I knew at a disk drive company. I
heat shrinked it over the crank. I guess for a wheel magnet you
could use some cable ties or some baling wire and attach one of
these to the spokes. The pick-up doesn't have to be so close to
the magnet when you use a disk drive magnet.


If heat shrink is too much trouble, the ?vinyl? stretchy plastic
electrical tape works pretty well also, I've done this for cadence
magnets. The tape may start to peel and degenerate into a sticky
mess, but if caught/redone in time, the mess is quite
containable.


I SPIT on electrical tape.



This is the stuff you want if you desire it stays put.

https://en.wikipedia.org/wiki/Self-amalgamating_tape

  #18  
Old May 13th 19, 07:56 PM posted to rec.bicycles.tech
Tosspot[_3_]
external usenet poster
 
Posts: 1,563
Default Wheel/Spoke Magnets

On 13/05/2019 12:46, John B. Slocomb wrote:
On Mon, 13 May 2019 07:06:48 +0200, Tosspot
wrote:

On 13/05/2019 01:45, John B. Slocomb wrote:
On Sun, 12 May 2019 16:26:11 -0700, "Mark J."
wrote:

On 5/12/2019 6:27 AM, sms wrote:
On 5/12/2019 1:29 AM, Tosspot wrote:
Anyone know of some 'decent' ones. The Sigma supplied
ones won't attract a whore in a crack house. The Bosch
type ones always seem to corrode and fall off, and on top
of that are easy to X-Thread. The Cat-Eye ones don't seem
to stay put[1]. The Echowell/Yamaha ones seem pretty
decent but are like rocking horse **** this side of the
pond. Any other ideas?

[1] Yes, it is getting OCD!

When I lost the cadence magnet on my crank I used a
hard-drive magnet, i.e.
https://www.ebay.com/itm/173209158372 but I got some used
ones from someone I knew at a disk drive company. I heat
shrinked it over the crank. I guess for a wheel magnet you
could use some cable ties or some baling wire and attach one
of these to the spokes. The pick-up doesn't have to be so
close to the magnet when you use a disk drive magnet.

If heat shrink is too much trouble, the ?vinyl? stretchy
plastic electrical tape works pretty well also, I've done this
for cadence magnets. The tape may start to peel and
degenerate into a sticky mess, but if caught/redone in time,
the mess is quite containable.

Mark J.

I bonded used Hard disk magnets onto the aluminum crank arms of
all of my (4) bicycles as much as 10 years ago using epoxy glue.
To date the magnets are all still attached :-)

As to the original post, I have spoke magnets that I attached to
front wheels both with radial spokes and with crossed spokes
that have been in place for 4 - 5 years.

What is the big problems with attaching magnets to bicycles?


It isn't a problem per se. For some reason there is a *big* gap
between the spokes and the Surly LHT frame, which means at best,
standard magnets are intermittent. The fix is obvious, a small
neodymium disc magnet, but this tends to cause enough of some
adverse force to cause the above problems. In short, the Sigma
ones don't cut the mustard, different ones work ok for a year or
two. I want a good magnet, that stays put, doesn't corrode and I
can't fyckup fitting.


I think that you are referring to a cycle meter pickup - spoke magnet
and sensor mounted on the front fork?


Errmmm...yes...that probably be one of them.

What I do is mount the magnet and than mount the sensor with a bit of
offset - bent in, one might say. Works for me :-)

The indomitable Sheldon recommends installing the magnet as near the
hub as possible as it means that the magnet passes the sensor
(transmitter) slower which he feels might make things more accurate.


He isn't wrong, but the trigonometry for my setup doesn't agree.

As an aside, it also means that the magnet is closer to the fork tube
and therefore the sensor is closer to the magnet and requires less
offset. See https://www.youtube.com/watch?v=q-eGGDFeaUM for an
example (I know it is a cabled meter but the position of the sender
is the same as a wireless sensor).


Now you come to mention it, I might try mounting it the other side of
the disc...
  #19  
Old May 13th 19, 10:59 PM posted to rec.bicycles.tech
John B. Slocomb
external usenet poster
 
Posts: 547
Default Wheel/Spoke Magnets

On Mon, 13 May 2019 03:56:59 -0700 (PDT), Sir Ridesalot
wrote:

On Monday, May 13, 2019 at 6:47:07 AM UTC-4, John B. Slocomb wrote:
On Mon, 13 May 2019 07:06:48 +0200, Tosspot
wrote:

On 13/05/2019 01:45, John B. Slocomb wrote:
On Sun, 12 May 2019 16:26:11 -0700, "Mark J."
wrote:

On 5/12/2019 6:27 AM, sms wrote:
On 5/12/2019 1:29 AM, Tosspot wrote:
Anyone know of some 'decent' ones.* The Sigma supplied ones won't
attract a whore in a crack house.* The Bosch type ones always seem to
corrode and fall off, and on top of that are easy to X-Thread.* The
Cat-Eye ones don't seem to stay put[1].* The Echowell/Yamaha ones seem
pretty decent but are like rocking horse **** this side of the pond.
Any other ideas?

[1] Yes, it is getting OCD!

When I lost the cadence magnet on my crank I used a hard-drive magnet,
i.e. https://www.ebay.com/itm/173209158372 but I got some used ones
from someone I knew at a disk drive company. I heat shrinked it over the
crank. I guess for a wheel magnet you could use some cable ties or some
baling wire and attach one of these to the spokes. The pick-up doesn't
have to be so close to the magnet when you use a disk drive magnet.

If heat shrink is too much trouble, the ?vinyl? stretchy plastic
electrical tape works pretty well also, I've done this for cadence
magnets. The tape may start to peel and degenerate into a sticky mess,
but if caught/redone in time, the mess is quite containable.

Mark J.

I bonded used Hard disk magnets onto the aluminum crank arms of all of
my (4) bicycles as much as 10 years ago using epoxy glue. To date the
magnets are all still attached :-)

As to the original post, I have spoke magnets that I attached to front
wheels both with radial spokes and with crossed spokes that have been
in place for 4 - 5 years.

What is the big problems with attaching magnets to bicycles?

It isn't a problem per se. For some reason there is a *big* gap between
the spokes and the Surly LHT frame, which means at best, standard
magnets are intermittent. The fix is obvious, a small neodymium disc
magnet, but this tends to cause enough of some adverse force to cause
the above problems. In short, the Sigma ones don't cut the mustard,
different ones work ok for a year or two. I want a good magnet, that
stays put, doesn't corrode and I can't fyckup fitting.


I think that you are referring to a cycle meter pickup - spoke magnet
and sensor mounted on the front fork? What I do is mount the magnet
and than mount the sensor with a bit of offset - bent in, one might
say. Works for me :-)

The indomitable Sheldon recommends installing the magnet as near the
hub as possible as it means that the magnet passes the sensor
(transmitter) slower which he feels might make things more accurate.

As an aside, it also means that the magnet is closer to the fork tube
and therefore the sensor is closer to the magnet and requires less
offset. See https://www.youtube.com/watch?v=q-eGGDFeaUM
for an example (I know it is a cabled meter but the position of the
sender is the same as a wireless sensor).

--

Cheers,

John B.


Some wireless magnets NEED to be mounted close to the rim in order to be picked up by the sensor which also needs to be as close to the actual computer unit as possible. I had a wireless computer that had intermittent readings and readings far in excess of my actual speed. Those problems were corrected when the magnet and sensor were moved as far up the wheels and fork as possible. It seems that the distance that the sensor was from the computer was a critical factor with that computer as it was a very short range from the sensor to the unit that worked.

Cheers


Yes, I have had meters that required the sensor to be mounted as close
to the instrument as possible. Notably the cheap in price meters. I
have not found this to be true in the more "expensive" brands, such as
CatEye for example.

Although I've not found CatEye to be really "expensive" in the real
sense. I recently gave away a bike with a CatEye "cable" meter that
had been installed for 10 or more years and was still going strong. In
fact I can't remember even having changed the battery in that thing
:-)

--

Cheers,

John B.
  #20  
Old May 13th 19, 11:10 PM posted to rec.bicycles.tech
John B. Slocomb
external usenet poster
 
Posts: 547
Default Wheel/Spoke Magnets

On Mon, 13 May 2019 07:01:02 -0700 (PDT), Frank Krygowski
wrote:

On Monday, May 13, 2019 at 6:57:02 AM UTC-4, Sir Ridesalot wrote:


Some wireless magnets NEED to be mounted close to the rim in order to be picked up by the sensor which also needs to be as close to the actual computer unit as possible. I had a wireless computer that had intermittent readings and readings far in excess of my actual speed. Those problems were corrected when the magnet and sensor were moved as far up the wheels and fork as possible. It seems that the distance that the sensor was from the computer was a critical factor with that computer as it was a very short range from the sensor to the unit that worked.


As I think I mentioned, my folding bike's wireless cyclometer lost the signal
from it's magnet and sender when the weather was cold. The small wheel diameter
meant the sender to cyclometer distance was within the unit's maximum separation
according to the manual, but just barely.

I finally solved the problem by mounting the cyclometer on a plastic stub in
front of the handlebar. It seems the handlebar itself was partially blocking
the radio signal.

- Frank Krygowski


Yes, I've seen this "phenomena" with meters I have used for "cadence
meters". Mount them on top of the top tube and they don't work. But
again, it seems to be more common with the cheaper (in price) meters,
which is again a problem as I prefer CatEye meters (cost versus
service) and would usually mount one as the handle bar meter and than
trying to use another CatEye for a cadence meter I find that the
signals from the two CatEye senders interfere with each other :-(
Probably they transmit on the same frequency) so I end up with a
cheaper meter for the cadence meter and have to mount the instrument
almost under the saddle to get it to work :-(
--

Cheers,

John B.
 




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