Its been a while but wanted to report back to the group. It has been a process with issues all along the way. But I got through it and it is all working perfectly now! But, still have one more question.
I acquired a pair of secondhand forks from the same year/model ('73, 500) via ebay. I looked for 550s, but they were significantly more expense.
At first, the bottom bolt of my original forks were free spinning. I tried a few things, but ultimately found that compressing the dampening rob all the way down created enough friction to hold the outer cup in place to break the bolt free. The bottom bolt on the new forks were completely corroded and stuck. I was eventually able to get the one on the non-brake side free, but the lower that I really needed to replace was really in there. I tried penetrating fluid, heat, extensions, drivers, etc. and eventually rounded the bit. I tried two different types of reverse-threaded removal bits, until the larger one sheered off, leaving the tip behind. I was about to give up an order another set, got upset at work, and decided to heat the thing until smoking, hammered on a larger hex bit, and smashed the hell out of an impact driver until it finally broke free!!
I semi-polished the lowers and reassembled on the the bike (putting the fender on the inside of the caliber mount!). I also purchase new bolts and washers from Partzilla to replace the random variety that were being use before.
In parallel, I also rebuilt the brakes, even purchasing new steel lines, etc. However, when installing those (from 4into1), the supplied bolts sheered off when tightening. Before you say that I over tightened, I wasn't even close, I promise. Just cheap crap. So I decided not to trust the lines or anything else from the kit, and had to swap back for the original ones. I installed the brake pad using CRC Brake Quiet on the piston mating service, and high-temp brake grease around the outside of the pad and inner walls of the caliber. Had some issues getting the air to bleed out, even with reverse bleeding and other tactics I saw online. Ultimately the trick for me was the run the bike, seemingly creating enough vibration to break the airlock and in a few squeezes, bubbles were released and it was tight as could be.
Took it for a spin and not a single squeak!
Only question I have remaining is how should the front forks feel? Previously, I could get them to bottom out by holding the brake pushing down (clearly not good). With the new fluid, there is still a lot of movement, though it doesn't bottom out. Cannot find in the manual any spec on the allowable travel distance. In speaking with a knowledgable friend, he suggested playing with the fluid levels and weight until I got the feel I liked (vs pre-loading the spring with washers etc). I used 160ml of 15W. I am a heavier rider, 250lbs/113KG. I will admit, she took the bumps way better on the test ride than before, so definitely an improvement in dampening. I guess I just expected it to be more firm/less travel.
Are there any thoughts on how to test/measure and tune the fork compression; what is a realistic expectation?
