I haven't actually taken them out to measure them yet but I see Pro-Bolt makes Ti ones and they all be very long. Is there any reason to have such a long bolt in there if the axle is at about SWB?

https://www.cheapcycleparts.com/oemparts/a/kaw/500b4e50f8700223e479607b/swingarm

55mm long. 5mm short might not be a problem... unless the axle is at it's max. Axle as far forward would not make the 5mm that much difference. And the threads have to be up to the head, remember. Run the nut up to the head and then count the flats out from the swing; so both sides are equal in spinout. Then see the notches and see how close those are equally?

Nor have I removed an adjuster bolt. The question is, how thick is the threaded hole? Say you use a shorter bolt; you don't want to expose the threads; tighten the nut and pull a few threads; because you didn't have that full bite of all the swingarm threads.

Run the nut up to the head and then count the flats out from the swing; so both sides are equal in spinout.

I have been using that method since my last sprocket change. As close to perfect as I can get by eyeballing it. I really can't get any closer by using the marks on my swing arm or the ones on my fancy-shmancy Gilles axle adjusters. I did notice a wear mark to the outer top edge of my chain guide this time. Just the back three inches or so. The rear sprocket is worn perfectly even on both sides this time where it used to wear more on the inside. Which wear marks are more in need of compensating for?...go figure. Maybe split the compensation straight down the middle if you can possibly figure out what that is. I plan to get one of those chain alignment tools that insert to the swing arm/lower rear engine mount. How much you want to bet all of these methods yield slightly different results? Then use a laser chain alignment tool and it will show a little different result too!

That chain guide wear along other OEM parts I am considering replacing is another topic I will post soon. The parts bill came out pretty high so I would like your opinion on whether to replace certain items or just keep them in service. I see some wear on certain parts and others look and work like new but have been used 50k miles. It's nice to replace stuff while you are already in there to do one job rather than tear it all apart a second or third time later on.

So back to the axle adjuster bolts, here we have some Ti M8 x 55mm ones that come with the lock nuts. Only $34.00 (and I'm worried about the cost of OEM replacement parts??!!!!).

https://www.probolt-usa.com/titanium-axle-adjuster-nut-bolt-set-m8-x-50mm-9.html

55 mm of thread, for stock wheelbase, the nut takes 10mm and there is probably another 10mm of threads between the nut and the head of the bolt. That leaves 35mm of male threads in that hole. That's a lot of darned threads in there but I guess yeah, if there ever might be a total failure of the axle nut, you'd want at leas 20mm of threads to hold the wheel back if you were operating the bike under severe load. Thirty mm would be better.

Thanks for the advice, Hub. Stay tune for my OEM replacement parts list thread or maybe I will just shoot you a PM.

55mm long. 5mm short might not be a problem... unless the axle is at it's max. Axle as far forward would not make the 5mm that much difference.

Hub, the Pro-Bolt titanium axle adjuster bolts are 55 mm long. I remembered a tutorial I wrote about installing Gilles axle adjusters and using the stock adjuster bolt as a failsafe. In that tutorial I wrote that with the axle on the fourth mark from the front, you WOULD want a stock length bolt in there. The fourth mark would be a possibility if I go from a 45T to a 41 or a 40 with the same chain on there. I'm sticking with the stock length bolts.