Originally Posted by
rpenmanparker
I disagree. The Velocity rims (if still available) feature 4 mm of offset which is quite substantial. ...
Rather than debate what is or isn't significant or whether it matters, I'll simply give you the basic math.
Assuming a rim is drilled in a straight line down the middle, the tension ratio is the inverse of the R/L CTF distance in the hub. For example, if a hub's CTFs are 35/20 then the tension on the left flange will be 20/35ths or 4/7th or 57% of the tension of the right. (This isn't super precise of subtle factors but it's close enough to work with.
Rim offset, either zigzag or all to the left will change the tension ratios by increasing or decreasing the effective CTF distance.
2 examples of the same 35/20 hub.
zigzag 2mm either side of center the effective CTFs would change to 33/18 and the tension ratio would be 18:33 or left = 54% of right, so zig zag drilling actually makes things worse.
Offset 4mm to one side of center the effective CTFs would change ro 31/24 and the tension ratio would be improved to 24:31 or L= 77% right which isn't equal, but is a decent improvement.
So those are the numbers. What anyone does with them is up to them based on their own judgement.