|
|
|
Thread Tools | Display Modes |
#11
|
|||
|
|||
[Bike related:] Tandem bottom brackets
On Mon, 23 Mar 2020 19:59:47 -0400, Frank Krygowski
wrote: On 3/23/2020 3:07 PM, Jeff Liebermann wrote: On Sun, 22 Mar 2020 19:58:17 -0500, AMuzi wrote: On 3/22/2020 7:40 PM, Jeff Liebermann wrote: On Sun, 22 Mar 2020 12:47:49 -0400, Frank Krygowski wrote: So I did the work with the tandem on the ground, meaning lots of bending over, getting up and down, moving the bike from one side of the workspace to the other, stretching for tools that were just out of reach. Was there room enough to invert the tandem? The bottom bracket would end up a little over 2ft off the shop floor. Not quite ideal height, but better than the 1ft elevation in the normal position. True, but when Frank drops a ball bearing it wends its way into the tandem tube maze instead of landing on the floor. I've used some old hard disk drive magnets to catch the ball bearings. I don't know if this works with every frame configuration but methinks it's worth a try. I also have some magnetic parts dishes to keep the ball bearings and small screws from rolling away after I accidentally kick the cat food cans I normally use for holding parts. https://www.harborfreight.com/search?q=magnetic%20parts%20holder The dish is stainless steel and can be used as an improvised grease removal tank to clean the bearings. As I vaguely recall, Frank's tandem frame is aluminum. Hah! When I bought this tandem, aluminum wasn't even invented! ;-) Actually, it's made of Reynolds 531 steel alloy, with oversized tubes. But for non-steel bikes, that's a good tip about the magnets. (And I gotta buy me a bore scope.) I used a magnet to help keep the loose balls from running away when I did that work the other day. I do worry a bit about that, though. I'm afraid the balls themselves will become a bit magnetized. Then I'll have to deal with eddy current losses as they rotate. A truly discerning cyclist can feel those eddy current losses. :-( On the other hand magnetic bearings may be the wave of the future providing nearly frictionless motion. https://www.youtube.com/watch?v=aSoCYi19NJ0 Think of it, no more nasty oil or grease, no more creaks and groans, no wear and can be used in CF bicycles. What's not to like? -- cheers, John B. |
Ads |
#12
|
|||
|
|||
[Bike related:] Tandem bottom brackets
On 24/03/2020 00:59, Frank Krygowski wrote:
On 3/23/2020 3:07 PM, Jeff Liebermann wrote: On Sun, 22 Mar 2020 19:58:17 -0500, AMuzi wrote: On 3/22/2020 7:40 PM, Jeff Liebermann wrote: On Sun, 22 Mar 2020 12:47:49 -0400, Frank Krygowski wrote: So I did the work with the tandem on the ground, meaning lots of bending over, getting up and down, moving the bike from one side of the workspace to the other, stretching for tools that were just out of reach. Was there room enough to invert the tandem?Â* The bottom bracket would end up a little over 2ft off the shop floor.Â* Not quite ideal height, but better than the 1ft elevation in the normal position. True, but when Frank drops a ball bearing it wends its way into the tandem tube maze instead of landing on the floor. I've used some old hard disk drive magnets to catch the ball bearings. I don't know if this works with every frame configuration but methinks it's worth a try.Â* I also have some magnetic parts dishes to keep the ball bearings and small screws from rolling away after I accidentally kick the cat food cans I normally use for holding parts. https://www.harborfreight.com/search?q=magnetic%20parts%20holder The dish is stainless steel and can be used as an improvised grease removal tank to clean the bearings. As I vaguely recall, Frank's tandem frame is aluminum. Hah! When I bought this tandem, aluminum wasn't even invented!Â* ;-) Actually, it's made of Reynolds 531 steel alloy, with oversized tubes. But for non-steel bikes, that's a good tip about the magnets. (And I gotta buy me a bore scope.) I used a magnet to help keep the loose balls from running away when I did that work the other day. I do worry a bit about that, though. I'm afraid the balls themselves will become a bit magnetized. Then I'll have to deal with eddy current losses as they rotate. A truly discerning cyclist can feel those eddy current losses.Â*Â*Â* :-( Magnetised ball bearings will "attract" iron alloy detritus from the road and will stick to them. Tbh, probably not an issue, but I have seen it. |
#13
|
|||
|
|||
[Bike related:] Tandem bottom brackets
On Tue, 24 Mar 2020 08:14:11 +0100, Tosspot wrote:
I do worry a bit about that, though. I'm afraid the balls themselves will become a bit magnetized. Then I'll have to deal with eddy current losses as they rotate. A truly discerning cyclist can feel those eddy current losses.Â*Â*Â* :-( Magnetised ball bearings will "attract" iron alloy detritus from the road and will stick to them. Tbh, probably not an issue, but I have seen it. Yep, just dro a magnet on the ground anywhere. Hint, pit it in a strong plastic bag first. Useful tool in its own right. |
#14
|
|||
|
|||
[Bike related:] Tandem bottom brackets
On 3/23/2020 4:59 PM, Frank Krygowski wrote:
On 3/23/2020 3:07 PM, Jeff Liebermann wrote: On Sun, 22 Mar 2020 19:58:17 -0500, AMuzi wrote: On 3/22/2020 7:40 PM, Jeff Liebermann wrote: On Sun, 22 Mar 2020 12:47:49 -0400, Frank Krygowski wrote: So I did the work with the tandem on the ground, meaning lots of bending over, getting up and down, moving the bike from one side of the workspace to the other, stretching for tools that were just out of reach. Was there room enough to invert the tandem?Â* The bottom bracket would end up a little over 2ft off the shop floor.Â* Not quite ideal height, but better than the 1ft elevation in the normal position. True, but when Frank drops a ball bearing it wends its way into the tandem tube maze instead of landing on the floor. I've used some old hard disk drive magnets to catch the ball bearings. I don't know if this works with every frame configuration but methinks it's worth a try.Â* I also have some magnetic parts dishes to keep the ball bearings and small screws from rolling away after I accidentally kick the cat food cans I normally use for holding parts. https://www.harborfreight.com/search?q=magnetic%20parts%20holder The dish is stainless steel and can be used as an improvised grease removal tank to clean the bearings. As I vaguely recall, Frank's tandem frame is aluminum. Hah! When I bought this tandem, aluminum wasn't even invented!Â* ;-) Actually, it's made of Reynolds 531 steel alloy, with oversized tubes. But for non-steel bikes, that's a good tip about the magnets. (And I gotta buy me a bore scope.) I used a magnet to help keep the loose balls from running away when I did that work the other day. I do worry a bit about that, though. I'm afraid the balls themselves will become a bit magnetized. Then I'll have to deal with eddy current losses as they rotate. A truly discerning cyclist can feel those eddy current losses.Â*Â*Â* :-( I should think that over a short period of time, the magnetic axis would tend to align with the spindle, minimizing the drag. For just $4,329,999, I can sell you a device to optimize this effect! Used by pros! Mark J. |
#15
|
|||
|
|||
[Bike related:] Tandem bottom brackets
On Mon, 23 Mar 2020 19:59:47 -0400, Frank Krygowski
wrote: Actually, it's made of Reynolds 531 steel alloy, with oversized tubes. But for non-steel bikes, that's a good tip about the magnets. (And I gotta buy me a bore scope.) I used a magnet to help keep the loose balls from running away when I did that work the other day. I suggest the 8mm diameter borescope. The big problem with using a borescope is the very limited depth of field (i.e. focus range). Also, try to get one that has adjustable LED lighting. Too much light is as bad a problem as not enough. All the one's I've bought have a removable right angle mirror for looking at tubing walls and around corners. Very handy, but also easy to have the mirror fall off inside the tubing. So, I sacrificed one camera and glued the right angle optics in place. Most common use is inspecting the cylinder walls on chain saws for scoring damage. I do worry a bit about that, though. I'm afraid the balls themselves will become a bit magnetized. Then I'll have to deal with eddy current losses as they rotate. A truly discerning cyclist can feel those eddy current losses. :-( Never mind the balls. Perhaps you should worry about the axle: "Demagnetizing Motor Shafts to Prevent Ball Bearing Failures" https://easa.com/DesktopModules/EasyDNNNews/DocumentDownload.ashx?portalid=0&moduleid=3015&art icleid=2196&documentid=797 For demagnetizing, I have a variety of tools. A generator "growler" for the big stuff, a 1/4" audio tape bulk eraser for the medium size stuff, and a tape recorder tape head eraser for small stuff. I also have a tape wound steel toroid coil that I attach to an old Weller soldering gun for demagnetizing. For ball bearings, methinks the tape bulk eraser would be best. When demagnetizing, do NOT turn off the bulk eraser with the axle or bearings still on the bulk eraser. Slowly remove the bearings (in a plastic bag) from the field, and then turn off the eraser. Otherwise, you might magnetize the bearings instead. I should probably check if any of my loose ball bearings that I have in stock are magnetized. Maybe later. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#16
|
|||
|
|||
[Bike related:] Tandem bottom brackets
On 3/24/2020 2:20 PM, Jeff Liebermann wrote:
On Mon, 23 Mar 2020 19:59:47 -0400, Frank Krygowski wrote: Actually, it's made of Reynolds 531 steel alloy, with oversized tubes. But for non-steel bikes, that's a good tip about the magnets. (And I gotta buy me a bore scope.) I used a magnet to help keep the loose balls from running away when I did that work the other day. I suggest the 8mm diameter borescope. The big problem with using a borescope is the very limited depth of field (i.e. focus range). Also, try to get one that has adjustable LED lighting. Too much light is as bad a problem as not enough. All the one's I've bought have a removable right angle mirror for looking at tubing walls and around corners. Very handy, but also easy to have the mirror fall off inside the tubing. So, I sacrificed one camera and glued the right angle optics in place. Most common use is inspecting the cylinder walls on chain saws for scoring damage. I do worry a bit about that, though. I'm afraid the balls themselves will become a bit magnetized. Then I'll have to deal with eddy current losses as they rotate. A truly discerning cyclist can feel those eddy current losses. :-( Never mind the balls. Perhaps you should worry about the axle: "Demagnetizing Motor Shafts to Prevent Ball Bearing Failures" https://easa.com/DesktopModules/EasyDNNNews/DocumentDownload.ashx?portalid=0&moduleid=3015&art icleid=2196&documentid=797 For demagnetizing, I have a variety of tools. A generator "growler" for the big stuff, a 1/4" audio tape bulk eraser for the medium size stuff, and a tape recorder tape head eraser for small stuff. I also have a tape wound steel toroid coil that I attach to an old Weller soldering gun for demagnetizing. For ball bearings, methinks the tape bulk eraser would be best. When demagnetizing, do NOT turn off the bulk eraser with the axle or bearings still on the bulk eraser. Slowly remove the bearings (in a plastic bag) from the field, and then turn off the eraser. Otherwise, you might magnetize the bearings instead. Actually, I remember my high school physics teacher demonstrating exactly that in front of the class. He was alternately magnetizing and demagnetizing something (I forget what) in front of the class, and asking what made the difference. I was the only one that spotted that he was turning off the coil at the end of the magnetizing cycle. That was back when electricity had just been invented. -- - Frank Krygowski |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Bottom Brackets | mark cleary | Techniques | 10 | December 27th 15 09:06 PM |
Bottom Brackets | J. D. Slocomb | Techniques | 10 | May 1st 11 12:24 PM |
Bottom brackets, etc. | HDGuzzi | Techniques | 7 | April 29th 08 09:25 PM |
Bottom brackets | Finlay Mackay | UK | 8 | August 11th 07 06:14 PM |
WTB: Bottom brackets | Dave Thompson | Marketplace | 1 | December 20th 04 03:16 PM |