Bottle holder
On Tue, 21 May 2019 21:21:12 -0400, Joy Beeson
wrote: I'm puzzled by the comment that one could cut oneself on the metal strap. I've been scratched by various bike parts, but the hose clamps have never even thought about it. That would be me. What I did was cut off the loose end of the metal strap flush with the hole clamp body. The down tube paint was protected by a strip of hard rubber. Over a few months, the clamp and rubber strip decided to move. So I tightened the screw on the clamp, which then exposed the end of the metal strap from the clamp body. I had previously rounded the sharp corners, but did not deburr the cut end. The result was a rather messy, but fortunately not very deep, slice in my leg when I performed an unscheduled and graceless dismount. I cut the metal strap shorter to avoid a repeat performance, but did nothing with the exposed hex screw head, which produced a minor gouge in the same place on my leg about a year later. I thought about putting a vinyl cap on the screw head, but instead switched to plastic ty-wraps and have not had any problems since then. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Bottle holder
On Thu, 23 May 2019 09:42:16 +0700, John B. Slocomb wrote:
One can only assume that you buy cheap junk that breaks a lot. My correlation is with kerb-hopping, especiallly when your timing is erratic on jumping up. YMMV, but when you stop that, then you stop bending/snapping frames. Rough riding down mountains and hills can be another, but it isn't usually the frame that comes off worse. |
Bottle holder
On Wed, 22 May 2019 21:53:31 -0700, Jeff Liebermann
wrote: On Thu, 23 May 2019 10:43:29 +0700, John B. Slocomb wrote: I would have to say, "But Why?" 1. With a drill guide, there's no need to center punch the frame tube or drill a pilot hole. Just clamp the jig to the tube, and drill. 2. Even with a pilot hole, keeping the drill bit from wandering is not easy. I'm rather bad at eyeballing an electric hand drill so that the bit is exactly perpendicular to the tube. 3. Because it's possible to do the drilling in my sleep, which is likely to be the case. 4. With an fully assembled bicycle (or frame), an off center hole, bad spacing between the Rivnuts, slip of the drill, or other alignment error, and much of the bicycle might be considered scrap metal. Best to build a proper jig and do it perfectly the first time. 5. Chances are good that one might be drilling holes in other frames for Rivnuts. It would therefore pay to build a jig to make it easier. After all it is only two holes about 7 cm apart. It is not, as they say, "Rocket Science". Not everyone has a machine shop or a machinists skills. Backyard mechanics are not known for their precision drilling. Best to give them a mechanical assist (i.e. a jig). Why not just mark the spot(s) for the holes on the frame and than just drill the holes? Even, if necessary, ding a bit of a mark on the tube with a center punch - I say that with a certain amount of caution, as I don't mean Whap It!, just a tiny little dimple, just enough to get the drill started. Then drill a pilot hole with, maybe a 1/16" drill, to make sure that the full size drill doesn't wander off the mark. Than just drill it. Sounds good, which brings me back to the previous problem. How is one going to rigidly clamp the frame to be able to drill the holes? However, that's now where the aforementioned procedure is going to screw up. What will happen is that both the center punch mark and pilot hole will probably be perfectly placed. What will fail is that the actual Rivnut hole drill will wander sideways if the drill is not perfectly perpendicular to the tubing. The drill needs some kind of clamping jig to keep it perpendicular. If it can't be done on a drill press or mill, then clamping a v-block and drill guide to the tube is a good substitute. Wander sideways? Good Lord! Can't you hold the drill perpendicular to the tube long enough to drill a hole ~1/64 inch deep? "Needs some kind of clamping jig"? Do you really think so? After all the frame tube (a good steel frame tube) is about 0.4mm thick (0.0156" - ~1/64"). Do you really think that the hole needs to be perfectly at 90 degrees to work... And if you do, think about drilling a hole in a tube. While the "center sides" of the hole - aligned longitudinally with the tube - may be at 90 degrees to the tube wall what about the sides of the hole? The curvature of the tube will guarantee that the holes will not be perpendicular to the surface of the tube. And even worse, you are installing a rivnut which has a top flange that is at 90 degrees to the shank, so what happens when you put that into a hole in a tube The curvature of the tube guarantees that the top flange is not going to be in contact with the outer wall of the tube except in two places. You don't even have to be terribly accurate as all the bottle cages I've seen have at least one of the mounting holes elongated to fit even if the mounting holes in the frame aren't perfectly spaced. Remind me not to let you work on any of my bicycles. Why ever not? After all, most machinists, or perhaps I should say "machinists of my era" could work to tolerances of 1/2 to 1/3rd of a 64th of an inch using a 6 inch steel scale (and a magnifier :-) Lets see, 1/64th is 0.015.625 inch and 1/3rd of that is 5.2 thousandths of an inch. Do you really believe that your bike frame is built to that standard? See https://forums.roadbikereview.com/co...ce-243456.html The frame was 5 mm(0.196") out of alignment and the guy is told "that is good enough". -- Cheers, John B. |
Bottle holder
On Wed, 22 May 2019 20:47:02 -0700, sms
wrote: On 5/22/2019 7:42 PM, John B. Slocomb wrote: snip What kind of crappy frames are you buying that you need a warrantee? Or perhaps, what kind of an awful rider are you that you feel that you break frames? I've never broken a frame. But most of my frames are steel. Jay has replaced his high-end lifetime Cannondale frame multiple times under warranty. The fact is that if you keep your bicycles for a long time, you're likely to experience a frame failure at some point in time, especially with aluminum or carbon fiber. You definitely don't want to void the warranty for such a ridiculous reason. snip How does one make an improperly drilled hole? Especially one with abnormal "stress risers" and micro-cracks? I ask as I successfully completed my apprenticeship as a journeyman machinist in 1950, which gives me what? Nearly 70 years of experience in drilling holes. Yes, as a journeyman machinist you should have no issue with properly drilling holes. Surely they taught you about stress concentration when drilling holes and how to increase fatigue life. snip Oh! Are you selling clamps to mount bottle cages now? Or do you get your kickback from simply referencing the web site these days? You might want to consider carefully how such ridiculous statements reflect on you. No, sorry, they didn't teach us about stress concentrations when drilling holes, primarily because any hole is a stress concentration, at least to some extent. And it is illogical to think that one can change "fatigue life" by drilling a hole in some special manner. And yes, I am familiar with making holes. When I was at the Edwards Test Center I worked on a project where we made various different sized orifices (holes) that were used in atmospheric sampling devices. The hole size was gauged by applying a specific air pressure and measuring the volume of air that flowed through the orifice in a specific time. As for ridiculous statements? Well, you are the one that told us that you got paid when someone accesses a site. I was only asking whether you got paid for that particular site. -- Cheers, John B. |
Bottle holder
On Wed, 22 May 2019 20:56:05 -0700, sms
wrote: On 5/22/2019 7:59 PM, Jeff Liebermann wrote: snip Ok, I yield. A V-block won't work on a finished bicycle frame. I tend to think in terms of what can be done on a drill press or milling machine. As you might suspect, I've never used Rivnuts on an a frame. Water Bottle Mount Drill Jig https://www.steintool.com/portfolio-items/water-bottle-mount-drill-jig/ snip Good idea to use this kind of tool to keep the bit straight and to prevent it from wandering, since you probably don't want to use a center punch on an aluminum frame. Also to achieve proper spacing. You could use this on a finished frame with a right-angle drill. I keep promising myself that I will ignore you but you keep coming up with increasingly stupid statements. Tell us, oh great pundit, why shouldn't one use a center punch on an aluminum frame? But before you start telling tall tales you should realize that when the hole is drilled it removes not only the center punch indentation itself but considerable (in reference to the size of the center punch dimple) material around the indentation. One person wrote: "I found that a standard power drill was difficult to align on the cylindrical steel tube; the bit tended to drift around the tube. Even after I created a small pilot hole for each boss, the bigger drill bit shifted to the side a little. In the end, once the cage was bolted in place, I realized that one of the bosses was misaligned along its cylindrical axis. Fortunately, it wasn’t off by much, but it tweaked the alignment ever so slightly and caused the cage to twist." Of course if you do go the Rivnut route you also want to ensure that you seal everything so moisture can't get in since you won't be painting the frame afterward. Goodness. Here is a thing that is literally riveted (which is why it is called a "riv(et) nut") into the bike frame. You don't think it will be water proof? -- Cheers, John B. |
Bottle holder
On Wed, 22 May 2019 22:16:46 -0700, Jeff Liebermann
wrote: On Tue, 21 May 2019 21:21:12 -0400, Joy Beeson wrote: I'm puzzled by the comment that one could cut oneself on the metal strap. I've been scratched by various bike parts, but the hose clamps have never even thought about it. That would be me. What I did was cut off the loose end of the metal strap flush with the hole clamp body. The down tube paint was protected by a strip of hard rubber. Over a few months, the clamp and rubber strip decided to move. So I tightened the screw on the clamp, which then exposed the end of the metal strap from the clamp body. I had previously rounded the sharp corners, but did not deburr the cut end. The result was a rather messy, but fortunately not very deep, slice in my leg when I performed an unscheduled and graceless dismount. I cut the metal strap shorter to avoid a repeat performance, but did nothing with the exposed hex screw head, which produced a minor gouge in the same place on my leg about a year later. I thought about putting a vinyl cap on the screw head, but instead switched to plastic ty-wraps and have not had any problems since then. Or simply rotate the clamp screw portion of the clamp to a position where you won't hit it :-) -- Cheers, John B. |
Bottle holder
On 5/22/2019 10:56 PM, sms wrote:
On 5/22/2019 7:59 PM, Jeff Liebermann wrote: snip Ok, I yield. A V-block won't work on a finished bicycle frame. I tend to think in terms of what can be done on a drill press or milling machine. As you might suspect, I've never used Rivnuts on an a frame. Water Bottle Mount Drill Jig https://www.steintool.com/portfolio-items/water-bottle-mount-drill-jig/ snip Good idea to use this kind of tool to keep the bit straight and to prevent it from wandering, since you probably don't want to use a center punch on an aluminum frame. Also to achieve proper spacing. You could use this on a finished frame with a right-angle drill. One person wrote: "I found that a standard power drill was difficult to align on the cylindrical steel tube; the bit tended to drift around the tube. Even after I created a small pilot hole for each boss, the bigger drill bit shifted to the side a little. In the end, once the cage was bolted in place, I realized that one of the bosses was misaligned along its cylindrical axis. Fortunately, it wasn’t off by much, but it tweaked the alignment ever so slightly and caused the cage to twist." Of course if you do go the Rivnut route you also want to ensure that you seal everything so moisture can't get in since you won't be painting the frame afterward. "don't want to use a center punch on an aluminum frame." Why ever not? "drill bit shifted to the side a little." With a centerpunch dimple and a drill sharpened to be symmetric they don't walk. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
Bottle holder
On 5/23/2019 5:45 AM, John B. Slocomb wrote:
On Wed, 22 May 2019 20:56:05 -0700, sms wrote: On 5/22/2019 7:59 PM, Jeff Liebermann wrote: snip Ok, I yield. A V-block won't work on a finished bicycle frame. I tend to think in terms of what can be done on a drill press or milling machine. As you might suspect, I've never used Rivnuts on an a frame. Water Bottle Mount Drill Jig https://www.steintool.com/portfolio-items/water-bottle-mount-drill-jig/ snip Good idea to use this kind of tool to keep the bit straight and to prevent it from wandering, since you probably don't want to use a center punch on an aluminum frame. Also to achieve proper spacing. You could use this on a finished frame with a right-angle drill. I keep promising myself that I will ignore you but you keep coming up with increasingly stupid statements. Tell us, oh great pundit, why shouldn't one use a center punch on an aluminum frame? But before you start telling tall tales you should realize that when the hole is drilled it removes not only the center punch indentation itself but considerable (in reference to the size of the center punch dimple) material around the indentation. One person wrote: "I found that a standard power drill was difficult to align on the cylindrical steel tube; the bit tended to drift around the tube. Even after I created a small pilot hole for each boss, the bigger drill bit shifted to the side a little. In the end, once the cage was bolted in place, I realized that one of the bosses was misaligned along its cylindrical axis. Fortunately, it wasn’t off by much, but it tweaked the alignment ever so slightly and caused the cage to twist." Of course if you do go the Rivnut route you also want to ensure that you seal everything so moisture can't get in since you won't be painting the frame afterward. Goodness. Here is a thing that is literally riveted (which is why it is called a "riv(et) nut") into the bike frame. You don't think it will be water proof? Like door panels in cars, water always gets in. The key point of design is to vent the piece with drainhole(s). -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
Bottle holder
On 5/23/2019 3:34 AM, John B. Slocomb wrote:
snip No, sorry, they didn't teach us about stress concentrations when drilling holes, primarily because any hole is a stress concentration, at least to some extent. And it is illogical to think that one can change "fatigue life" by drilling a hole in some special manner. It is not illogical at all. It is a fact. There is just no way that any course in machining would not teach about how to reduce stress concentration of holes drilled into metal. You might want to ask for a partial refund if that school is still in existence. We just had a spectacular example of the result of improper drilling of holes in steel beams in San Francisco, but these were not drilled by journeyman machinists. |
Bottle holder
On 5/23/2019 3:45 AM, John B. Slocomb wrote:
snip. Goodness. Here is a thing that is literally riveted (which is why it is called a "riv(et) nut") into the bike frame. You don't think it will be water proof? Rivnuts routinely become loose, even when installed at the factory. Some sort of sealant, or paint, should be used to fill the gaps that will exist. |
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