Spoke length terminology: i-light and dyad
12-26-08, 08:46 AM
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Spoke length terminology: i-light and dyad
I'd like to build up a 36-hole (cross 3) front wheel from an SRAM i-light hub and a velocity dyad rim, and I'm trying to figure out what spoke lengths to order while I wait for the hub to arrive.
The spocalc excel file has an entry for the velocity dyad rim, but not for the hub, so I have a couple of questions.
1) The above i-light manual gives a "spoke hole reference theta" of 80mm. Is this the "flange diameter" of spocalc, which is 74mm for the shmano DH-3N70? The i-light manual also lists a "spoke flange distance" of 60mm, which is the same of the sum of the two "center to left/right flange" distances for the shimano. Adjusting the spreadsheet with 80 instead of 74 for the flange diameter gives me a spoke length of 280.5mm. Does this sound reasonable?
2) the i-light manual lists a spoke hole of 2mm. I thought most were on the order of 2.6mm. Will I be able to put a wheelsmith DB14 spoke through that hole?
Thanks,
pete
The spocalc excel file has an entry for the velocity dyad rim, but not for the hub, so I have a couple of questions.
1) The above i-light manual gives a "spoke hole reference theta" of 80mm. Is this the "flange diameter" of spocalc, which is 74mm for the shmano DH-3N70? The i-light manual also lists a "spoke flange distance" of 60mm, which is the same of the sum of the two "center to left/right flange" distances for the shimano. Adjusting the spreadsheet with 80 instead of 74 for the flange diameter gives me a spoke length of 280.5mm. Does this sound reasonable?
2) the i-light manual lists a spoke hole of 2mm. I thought most were on the order of 2.6mm. Will I be able to put a wheelsmith DB14 spoke through that hole?
Thanks,
pete
12-26-08, 01:18 PM
#2
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The SRAM Tech Manual gives a center to center spoke hole reference of 71mm rather than the 80mm you mentioned and a hole diameter of 2.5mm. Both of these are per the 2008 Gear Hub Systems Technical Manual. I suspect that the 80mm is the overall spoke flange diameter. This manual, and the 2009 version are available on the SRAM web site. Here is the link to the downloads page.
https://www.sram.com/en/service/sram/tech_manuals.php
The only way to be sure which is correct is to measure the hub but I favor the Tech Manual dimensions as more likely correct.
https://www.sram.com/en/service/sram/tech_manuals.php
The only way to be sure which is correct is to measure the hub but I favor the Tech Manual dimensions as more likely correct.
12-26-08, 04:04 PM
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This site helps with explanations of measurements for spocalc.
https://sheldonbrown.com/rinard/spocalc.htm
Other spoke caclulation sites to add confusion to the process:
https://www.bikeschool.com/spokes/
https://vocabforbreakfast.railsplayground.net/edd/
https://houseof3d.com/pete/applets/wheel/appwheel.html
https://www.dtswiss.com/SpokesCalc/We...px?language=en
https://sheldonbrown.com/rinard/spocalc.htm
Other spoke caclulation sites to add confusion to the process:
https://www.bikeschool.com/spokes/
https://vocabforbreakfast.railsplayground.net/edd/
https://houseof3d.com/pete/applets/wheel/appwheel.html
https://www.dtswiss.com/SpokesCalc/We...px?language=en
Last edited by wmodavis; 12-26-08 at 04:09 PM.
12-27-08, 08:15 AM
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The SRAM Tech Manual gives a center to center spoke hole reference of 71mm rather than the 80mm you mentioned and a hole diameter of 2.5mm. Both of these are per the 2008 Gear Hub Systems Technical Manual. I suspect that the 80mm is the overall spoke flange diameter. This manual, and the 2009 version are available on the SRAM web site. Here is the link to the downloads page.
https://www.sram.com/en/service/sram/tech_manuals.php
The only way to be sure which is correct is to measure the hub but I favor the Tech Manual dimensions as more likely correct.
https://www.sram.com/en/service/sram/tech_manuals.php
The only way to be sure which is correct is to measure the hub but I favor the Tech Manual dimensions as more likely correct.
Cheers,
pete
Last edited by quester; 12-27-08 at 08:18 AM.
12-27-08, 01:02 PM
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Pete;
The joys of eBay. If you have a caliper, or even a metric tape measure, you should be able to measure from spoke flange centerline to mounting flange surface well enough to determine what you have. Also if no disc brake or iBrake mounting holes on the hub that will eliminate several models. Whether or not a quick release axle version should cut it down further.
The joys of eBay. If you have a caliper, or even a metric tape measure, you should be able to measure from spoke flange centerline to mounting flange surface well enough to determine what you have. Also if no disc brake or iBrake mounting holes on the hub that will eliminate several models. Whether or not a quick release axle version should cut it down further.
Last edited by tatfiend; 12-27-08 at 01:03 PM. Reason: correct spelling
