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Hub Center to Flange Center???
I'm playing with a spoke calculator. Why do we need "Hub Center to
Flange Center"? What does it give me that I use in the wheel? If the wheel is symmetric, then what difference does it make? I'm looking at http://www.bikeschool.com/spokes/index.cgi I also note that the distance between the flanges isn't an input. Can I calculate the width of the wheel (meaning the flanges) from that? I don't think I'm measuring it right. Jones |
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#2
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Hub Center to Flange Center???
On Aug 25, 9:58 am, !Jones wrote:
I'm playing with a spoke calculator. Why do we need "Hub Center to Flange Center"? What does it give me that I use in the wheel? If the wheel is symmetric, then what difference does it make? I'm looking athttp://www.bikeschool.com/spokes/index.cgi I also note that the distance between the flanges isn't an input. Can I calculate the width of the wheel (meaning the flanges) from that? I don't think I'm measuring it right. Jones Trigonometry, my dear boy. The distance from hub center to the flange gives you the base of the triangle where the vertical distance from the hub to the rim is the height and the spoke forms the hypotenuse. Without knowing this measurement, you can't correctly determine the spoke length. Many hubs (most rear and some front) are not symmetrical right-to- left. You need to determine the distance from center to flange on each side to get the lengths exactly right. It can make a difference- highly dished rear wheels can have a difference of 2mm from left to right. Try using Spocalc: http://sheldonbrown.com/rinard/spocalc.htm . The spreadsheet includes data on many common rims and hubs, and allows independant data entry for items not included. It's never let me down. Jeff |
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Hub Center to Flange Center???
On Sat, 25 Aug 2007 11:19:51 -0700, in rec.bicycles.tech JeffWills
wrote: Trigonometry, my dear boy. The distance from hub center to the flange gives you the base of the triangle where the vertical distance from the hub to the rim is the height and the spoke forms the hypotenuse. Without knowing this measurement, you can't correctly determine the spoke length. Many hubs (most rear and some front) are not symmetrical right-to- left. You need to determine the distance from center to flange on each side to get the lengths exactly right. It can make a difference- highly dished rear wheels can have a difference of 2mm from left to right. Try using Spocalc: http://sheldonbrown.com/rinard/spocalc.htm . The spreadsheet includes data on many common rims and hubs, and allows independant data entry for items not included. It's never let me down. Jeff Ya know, my dear boy, what we need are four points: Trigonometry, my dear boy. The distance from hub center to the flange gives you the base of the triangle... A distance alone does not give you the base of a triangle... if you knew trig, dear boy, then you'd already know that; if all you have is distance, you're not in Euclidean space yet, so it's nonsensical to start talking about triangles until you unequivocally fix three noncolinear points. (Actually, I think you're fixing two and taking a perpendicular delta, but that's not what you wrote.) Useless post. Go back and review your undergraduate trig and don't address me as "my dear boy" until you're sure that you know your subject... I'm pretty well up to date on my trig... "dear boy". Jones |
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Hub Center to Flange Center???
On Sat, 25 Aug 2007 13:31:13 -0700, in someplace JeffWills
wrote: OK- *you* explain to *me* how you're going to calculate spoke length without knowing how far the flange is from the center of the hub. That's what I was asking. Is that what it is? Would zero mean that you only had one flange? (That would be an unstable wheel, naught?) Would 0.5" mean that the centers were an inch apart? Jones |
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Hub Center to Flange Center???
On Sat, 25 Aug 2007 12:58:08 -0500, !Jones wrote:
I'm playing with a spoke calculator. Why do we need "Hub Center to Flange Center"? What does it give me that I use in the wheel? If the wheel is symmetric, then what difference does it make? I'm looking at http://www.bikeschool.com/spokes/index.cgi I also note that the distance between the flanges isn't an input. It is, in a sense. Lefthand Hub-Center-to-Flange-Center distance + righthand Hub-Center-to-Flange-Center distance = distance between flanges. What may be confusing you is that this particularly calculator only does one side of a wheel at a time. Can I calculate the width of the wheel (meaning the flanges) from that? I don't think I'm measuring it right. Jones This page has a diagram: http://www.damonrinard.com/spocalc.htm Scroll down to "How to Measure Hub and Rim Dimensions." "Hub Center to Flange Center" is the same thing as WL and WR on the diagram. (That's W-subscript-L, W-subscript-R.) |
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Hub Center to Flange Center???
On Sat, 25 Aug 2007 15:40:57 -0500, in rec.bicycles.tech Gary Young
wrote: It is, in a sense. Lefthand Hub-Center-to-Flange-Center distance + righthand Hub-Center-to-Flange-Center distance = distance between flanges. What may be confusing you is that this particularly calculator only does one side of a wheel at a time. Oh... well, that's a "light bulb moment"! Got it! Thanx! Jones |
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Hub Center to Flange Center???
On Aug 25, 1:24 pm, !Jones wrote:
On Sat, 25 Aug 2007 15:40:57 -0500, in rec.bicycles.tech Gary Young wrote: What may be confusing you is that this particularly calculator only does one side of a wheel at a time. Oh... well, that's a "light bulb moment"! Ah-ha! My own light bulb moment: you were using a crappy spoke calculator. Spocalc is so much nicer. I will now retire to my couch and cats. Jeff |
#8
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Hub Center to Flange Center???
On Aug 25, 11:58 am, !Jones wrote:
I'm playing with a spoke calculator. Why do we need "Hub Center to Flange Center"? What does it give me that I use in the wheel? If the wheel is symmetric, then what difference does it make? I'm looking athttp://www.bikeschool.com/spokes/index.cgi I also note that the distance between the flanges isn't an input. Can I calculate the width of the wheel (meaning the flanges) from that? I don't think I'm measuring it right. Jones When measuring hub dimensions you need 2..flange diameter..center hole to center hole across the hub flange and center of the hub to flange dimension on each side and yes, if the hub is symmetric, the spoke lengths will be the same on each side. |
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