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#21
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Wheel/Spoke Magnets
On Mon, 13 May 2019 20:52:15 +0200, Tosspot
wrote: 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 That seems to be the original name for it as I now find it in Home Pro (which I believe should be named Home Amateur) marked "Splicing Tape". I use it mostly for finishing off handle bar tape, but back when I worked as an electrician it was the first layer in insulating of a higher voltage - 4160 VAC - splice. -- Cheers, John B. |
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#22
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Wheel/Spoke Magnets
On 5/13/2019 4:59 PM, John B. Slocomb wrote:
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 :-) -- Cateye has a spec for that. Magnet to sensor 5mm, sensor to receiver 70cm for the current Urban Wireless. Just a few years ago that was 2mm and 40cm which was difficult to set up on some large bikes. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#23
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Wheel/Spoke Magnets
On Monday, May 13, 2019 at 11:39:25 PM UTC+1, AMuzi wrote:
On 5/13/2019 4:59 PM, John B. Slocomb wrote: 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. |
#24
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Wheel/Spoke Magnets
On 13/05/2019 16:56, Jeff Liebermann wrote:
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. Well, one old HDD reduced to component parts, we'll see how it goes over the weekend. |
#25
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Wheel/Spoke Magnets
On Tuesday, May 14, 2019 at 1:59:01 AM UTC-7, Andre Jute wrote:
On Monday, May 13, 2019 at 11:39:25 PM UTC+1, AMuzi wrote: On 5/13/2019 4:59 PM, John B. Slocomb wrote: 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 :-) -- Cateye has a spec for that. Magnet to sensor 5mm, sensor to receiver 70cm for the current Urban Wireless. Just a few years ago that was 2mm and 40cm which was difficult to set up on some large bikes. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 I'm too lazy to look up the spec now, but I had a bike computer/wris****ch/heart rate monitor that had a spec for all its senders (crank, fork, breast belt) to main unit of 18in max, and at that it didn't often work beyond 12in. In addition, even on my wrist it was out of spec. For north of STG300 I expected something more useful than a meter that forced me to crouch on my bike like a gorilla in too small a cage. Andre Jute Mind you, it was perfectly scaled to my bonobo (a sort of extra-intelligent chimpanzee), MiniAndre, who stood nearly 3ft high in his latex, or even sitting down on his unicycle. I guess it's the new Fitbit by brother had. He had it die half way into the metric the other day. He said it was still charged but that it simply stopped working at 20 miles. |
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