Derailed

Hi,

I know this topic comes up regularly, but I can't find something that quite answers my question: how far down is it acceptable to round down spoke length based on a value produced from a spoke length calculator (e.g. Damon Rinard's Excel spreadsheet).

For example, I've got a Shimano Nexus Inter-8 (SG-8R25) internally geared hub and a Mavic MA3 rim (36 holes for both). Although the SG-8R25 is not listed in the database of hubs, Sheldon Brown confirmed for me that the slightly older SG-8R20 has the same relevant dimensions.

Accoding the the spreadsheet I should use 283.8 and 283.2 mm spokes for the left and ride sides, respectively, since I'd like to use a 3-cross pattern for the 36 spokes.

However, the store from where I purchased the spokes only had even sizes. I remembered the rule to round down and went with 282 mm spokes, and am now wondering if I should have shopped around for 283 mm spokes. The rim has not yet come in, and I've got a tour planned strating in one week using this wheel, so this has left me with time to worry about such things.

So, my ultimate question: if Spokecalc recommends 283.8 mm and I round down to 282 mm, have I gone too far?

Thanks for your time,

D

Derailed

Turns out my LBS doesn't have 283; the closest they have is 284 mm.

So, as it stands now I can round down from 283.8 and 283.2 (left and right) to 282 mm or round up to 284 mm. If it will work I'd definitely prefer to stick with the 282's I already have because it will be a good bit cheaper.

I suppose I could get 18 284s and use those for the left and stick with the 282s for the right...

Any suggestions? Thanks for reading.

-D