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I’ve notice a few occasions where my chain adjuster bolt has backed itself off of the rear axle up into the swingarm. The bolt itself has just a dab of anti seize on it and I’ve torqued everything to spec with a hair extra to try to stop it, but it persists. It doesn’t seem to cause an issue with the rear wheel alignment, but it’s still pretty annoying. Anyone know a simple fix or tightening technique to prevent this? Picture for reference.
Maybe you got some anti-seize between the face of the lock nut and the surface of the swingarm. Remove the bolt completely and wipe both those surfaces clean with a little contact cleaner.
Good suggestion. I’ll try it. Thank you.
It's definitely something you want to correct. If you've ever seen someone get their rear wheel cocked you know all the bad stuff that can happen.
That’s what I reckoned. Hast given me an issue yet but it will eventually. If cleaning the surfaces doesn’t remedy it I may take a chisel and put some shallow notches in the swingarm there so the nut can get some purchase.
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One thing I’ll add here is make sure the flat surface on the swing arm is nice and flat and DO NOT use loc-tite. If you loc-tite it and it snaps down the track, you’ll have a not so great time trying to get it out.
Noted on the loctite. I’ve always used the silver paste antiseize there because it’s a low spot that water seems to settle in and those swingarm threads are usually the first to rot out.
As for the flat spot on swingarm, how do I check to make sure it is and how would I make it flat if not?
Are you doing it right? Go over your process
With the flat surface just use a steel rule with a straight edge, if it’s not flat it’ll be fairly obvious.
When I do my chain tension I pull my wheel back out and use the ring ends of my spanner’s to snug everything up properly.
Why would anti-seize on the face of the lock nut cause it to come loose? Maybe i am misunderstanding that point...also, these bolts are only meant for setting chain tension/even wheel space in the swingarm. When axle nut is torqued, it really shouldn't matter about the bolts right? I would want to know why it backs off though myself.
Don't chisel your swingarm!
A few things to try:
* I Always back thread the adjuster bolts up against the chain blocks, after doing the axle up. I'm only talking a poofteenth of a turn, if you can even get that. If anymore than a poofteenth is achievable, it suggests you've problems with the actual thread in the swingarm . Even with the wheel pulled tight with either a rag (preferable) or a spanner / screw between the chain and sprocket, you can have movement during the axle tightening process. "Preloading" the bolt back up against the block might do the trick.
* If you've got enough thread showing on the adjuster bolt, you could double nut it. If you run the rear wheel back, you should have enough room to do that, yet still have enough adjustment to move the wheel forward enough to get the chain off during work on the bike, even with the adjuster blocks not 'popped away from the bolts.
* You could try a mild loctite such as 222 - often called Screw lock - on the thread Only where the lock nut goes (while Always having anti seize on the adjuster threads / threads in the swingarm. I'm a great fan of the stuff, in that it helps with vibration related loosening on (generally) lighter duty bolts, nuts and screws. The LH seat bolt on my old Beast comes undone, no matter the correct torque - with 222 on it , it stays in place, with no struggling to get it out when it's needed to do so. Heck, if you do the 'double nut thing, I'd use the 222 on the area the extra nut is on.
Not having the adjuster bolt bearing against the axle blocks - well, as you and others have said, that's a recipe for disaster! It's under a compressive , straight load, and even an 8mm / 10mm bolt, is a serious thing to try to compress.
Thanks Bear, you’re right about the chisel—probably a stupid idea on my part.
As for the tightening process, I do everything you said. Adjust the bolts with a rag stuffed in the sprocket, tighten rear axle, then back the adjuster bolts out so they snug up against the blocks before tightening the retention nuts. The problem persists.
I’m still a little leery about getting loctite in swingarm threads, but you’ve given me another idea. What about replacing the nut with a nylock nut?
Just use a lock washer
My Kawi used to do this. I got it to stop by tightening the 12mm lock nut before I tighten the axle. It doesn't make sense, but it's working for me.
Thought about that but worried it’ll chew up the swingarm.
I got my 2020 yz to quit by using these.
Yes, a Nyloc nut would be good - just have a washer that matches the original nuts flange diameter between it and the swingarm. It takes biting your tongue just the right way to get a Nyloc Nut started in the opposite direction - well, it does for me.
Not a spring washer, as they can have a tendency, at times, to mar the surface they are up against , as TheGetFresh said.
And, as Sandusky26 wrote, sometimes just a different approach works, and you'd be buggered if you knew why....
gristle568 has had the non nutted, captured bolt system work for him.
But, conversely, I've a mate whose set up like that - not the Bolt product - comes loose often. I've got that exact set of those to use hanging on the wall, and have no fear of them - If I ever pull my finger out and make a new Steel swingarm for my PDS'd CRE500 - and I intend to use them. Though, the STARK set up is even neater. But, the way I'm going, with 'projects' there's fat chance of that happening.........
The lock nut needs purchase/bite against the swingarm to stay tight. If there is anti-seize in there it can allow the lock nut to loosen. Once it loosens, it no longer serves its purpose and the adjuster bolt is free to work itself into the swingarm.
Side note, Billy from @Luxon could come in here and teach us a lesson on how anti-seize on that face also serves as a lubricant and affects the torque setting when you tighten that lock nut down. Layman's translation - it will allow you to overtighten it and possibly bungle the threads up.
The bolts 100% serve more than just an axle position setting purpose. They prevent the axle from being pulled forward out of position while in operation. The tension on the axle nut alone is not capable of doing this. By virtue of common sense you can see that if one bolt stays in place and the other backs up into the swingarm, you have a recipe for disaster (especially if it is the left/drive side bolt that backs into the swingarm). Long story short, it will only take 1 good impact or yank of the chain to pull the wheel out of alignment. Once that happens, a derailed chain, broken hub, mangled sprocket, mangled chain guide, etc etc... are all possibilities. I've seen this occur on multiple occasions. Obviously, it's something we'd all like to avoid.
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