Just thought I'd let others know, even though I'm sure this is one of those things everyone but me has been aware of.
For anyone running bikes with older forks, the recommendation is often to go to 30W fork oil. This is virtually impossible to find in my area and just gets snickers from the motorcycle parts counters.
However evidently one can use 30W non detergent oil, which is luckily very plentiful as its used in some car transmissions and older cars in general. The important thing is that it's single weight and non detergent. It's cheaper than regular fork oil as well.
Now I USUALLY keep myself out of all oil and tire threads as they are a bit like starting a war, but this seemed worth passing on.