Getting the chainline right for a 127mm drop out

i'll be embarking on my second conversion but will have to deal with the chainline this time - an issue that i didn;t have to address with my first effort.

having read in a previous thread and other sources on the Internet, I've gathered that a 120mm drop out requires a 42mm chainline. I'm taking an educated guess that the chainline will have to be a little bit bigger for a 127mm jobby. but by how much and how do i go about getting it right?

Do i have to use spacers? (I've seen some on hubjub for the chainring). and what are the consequences on the rear wheel? I'll be going to BLB this weekend to get a pair, what should i ask for to ensure that i get the chainline spot on?

having not dealt with this issue before it all seems utterly hard core but i'm well up for it so hit me with it!

I think BB is the best way to get a good chainline.

the OLN isn't what affects the chainline in this case really.

the sprocket will still sit in the same place with relation to the centre of the hub/BB

sheldon it

your dropouts sound as if they should be 126mm, which was an older standard

thanks, i'll have a better look on sheldon but Re: wheel, i was just wondering if i have to ask for a longer axle or get them to do something to fit in between the drop outs snugly.

depends on the hub

you might add some spacers, you might squeeze the dropouts in on a steel frame (not ideal IME).
goldtec make different length axles for their track hubs, 120, 126, 130..