Spoke length question

O-Dawg said:

I have a Sun T17 rim and a Shimano FH-M330 (also known as Acera)
rear hub and would like to build a wheel. Have a few questions on
measurements and lengths..

The hub dimensions I measured are diameter - 45 mm, left offset 20 mm,
right offset 32 mm.

I measure rim diameter as 610 mm. That's the distance where spokes
would be level with the eyelets inside the rim. Is this the right way
to measure effective rim diameter?

For a 36 spoke 3x rear wheel Damon Rinard's spreadsheet gives 296/297
mm spokes. The DT calculator at
http://www.dtswiss.com/spokescalc/Calculator.aspx
gives 293/294 mm.

is a 3 mm difference enough to worry about?

Thanks!

Yes, 3 mm is enogh to make one go back and check.
When I entered your number in Damon Rinard's spreadsheet I came up with 293/294 mm.

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daveornee said:

O-Dawg said:

I have a Sun T17 rim and a Shimano FH-M330 (also known as Acera)
rear hub and would like to build a wheel. Have a few questions on
measurements and lengths..

The hub dimensions I measured are diameter - 45 mm, left offset 20 mm,
right offset 32 mm.

I measure rim diameter as 610 mm. That's the distance where spokes
would be level with the eyelets inside the rim. Is this the right way
to measure effective rim diameter?

For a 36 spoke 3x rear wheel Damon Rinard's spreadsheet gives 296/297
mm spokes. The DT calculator at
http://www.dtswiss.com/spokescalc/Calculator.aspx
gives 293/294 mm.

is a 3 mm difference enough to worry about?

Thanks!

Yes, 3 mm is enogh to make one go back and check.
When I entered your number in Damon Rinard's spreadsheet I came up with
293/294 mm.

My mistake! I had 32 spokes in spokecalc.xls, not 36. Correcting it
gave the 293/294 lengths.

Thanks!

In article <[email hidden]>, O-Dawg

Quoted message said:

daveornee said:

O-Dawg said:

I have a Sun T17 rim and a Shimano FH-M330 (also known as Acera)
rear hub and would like to build a wheel. Have a few questions on
measurements and lengths..

The hub dimensions I measured are diameter - 45 mm, left offset 20 mm,
right offset 32 mm.

I measure rim diameter as 610 mm. That's the distance where spokes
would be level with the eyelets inside the rim. Is this the right way
to measure effective rim diameter?

For a 36 spoke 3x rear wheel Damon Rinard's spreadsheet gives 296/297
mm spokes. The DT calculator at
http://www.dtswiss.com/spokescalc/Calculator.aspx
gives 293/294 mm.

is a 3 mm difference enough to worry about?

Thanks!

Yes, 3 mm is enogh to make one go back and check.
When I entered your number in Damon Rinard's spreadsheet I came up with
293/294 mm.

My mistake! I had 32 spokes in spokecalc.xls, not 36. Correcting it
gave the 293/294 lengths.

Thanks!

Just a question regarding the OP's measurements: Have the offset
measurements (I interpret these as the distances from the flanges to
the hub center line) been reversed? On freewheel/cassette hubs, the
right side, i.e. the drive side, always has a lesser offset than the
left (non-drive) side.

Be sure to orientate the hub correctly before building.

Luke