I have a R60/6 that I am restoring, it has sat in a shed for 30 years. It has the optional disk on the front wheel, so it is just like a R75/6.
I am now at the stage where I am respoking the wheels with stainless spokes because the originals are rusty.
I have done the rear wheel following Snowbums instructions, but I am very confused about how to do the front wheel. I have spent a few hours trying to find the answer on line, but am stumped, so I'm hoping one of you can help me.
The offset for a R75/6 front wheel is 5.5 to 6mm but is that to the left (looking forward) or the right? The rear rim offsets to the left (away from the drum) so does the front rim go the same way?
OK that seems a reasonable question, however the as yet unmolested front rim (ie it still is spoked with the original spokes) appears centered on the rim. Using a flat edge on either side of the front hub with the disk removed the gap is the same between the flat edge and the rim. I haven't measured it exactly because after 47 years the rim isn't perfectly true, but it is about 5mm each side.
So (for arguments sake) if the rim is offset 5.5 - 6mm to the left does this result in the right side also being offset a similar amount, in other words it is centered or very nearly so???
Hurting my head trying to figure this out caused another thought. For the front wheel why not center the rim on the hub and move it left or right with spacers.
I need a beer......
Thinking a bit more about this...I wondered what the difference between the rim and hub width was.
Rim width 66mm. Hub width 77mm. Difference obviously 11mm.
Offset for front wheel is 5.5 to 6.00mm. Lets call it 5.5mm which is half of 11mm so the rim is centered on the hub and can be measured from the left or the right.