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spoke length: size up one mm?

Old 12-27-08, 10:06 AM
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spoke length: size up one mm?

spocalc is giving me 295.4 as spoke length for my fixed gear build on an older araya 20A 700c rim mated to a formula th21 flip flop hub.

My plan is to size up from 295 to 296mm spoke length to be safe.

The araya 20A 700c rim is listed in various databases as having 611 mm ERD. My measurements averaged between 609mm and 611mm.

Any arguments in favor of 295mm spoke length in this scenario?

thanks
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Old 12-27-08, 11:47 AM
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My rule of thumb is that plus or minus 1 mm will be OK.

If you're in doubt it's better to be a little too short than a little too long. If your spokes are too long you may run out of spoke threads before the wheel comes up to tension.
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Old 12-27-08, 11:54 AM
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Always round down to the shorter length. Nothing worse than running out of threads when approaching that ideal high tension. I round down at least 1 mm on the drive side rear when using double butted spokes to compensate for stretch.

Al
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Old 12-27-08, 02:51 PM
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I would usually size down, but if your rim is double wall, then 1 or 2mm extra is very unlikely to cause any problems.
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Old 12-27-08, 03:10 PM
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Originally Posted by cascade168
I would usually size down, but if your rim is double wall, then 1 or 2mm extra is very unlikely to cause any problems.
didn't consider that. yes, the older Araya 20A 700c I'm using is double wall.
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Old 12-27-08, 08:20 PM
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Originally Posted by Al1943
Always round down to the shorter length. Nothing worse than running out of threads when approaching that ideal high tension. I round down at least 1 mm on the drive side rear when using double butted spokes to compensate for stretch.

Al
+1 Round Down.
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