Chain adjuster came loose

[backinthesaddleagain]

OK so I put a new rear tire on a couple weeks back and have done about 100 miles since. Today I was going to work and when I went to start the bike I saw the left side (chain side) adjuster was way loose and the threaded part had bent. Also the cap that goes on the end of the swingarm must have popped out and rotated around. It must have hit a sprocket bolt, got gouged up and caused the threaded part to bend.

Wheel was still aligned so I straightened the threaded part as best as possible, pushed the cap back on and tightened the 2 nuts. Ordered a new adjuster and cap today.

I know I put them on good and snug when I changed the tire as my wife slid the axle in while I held the wheel and caliper in place and I showed her how the chain gets adjusted. Maybe in hindsight I didn't put it tight enough?? Never had that happen before on any dirtbike. Maybe blue loctite is called for??

[kkim]

how tight did you make the axle nut? after that's tightened down properly, I don't see how the adjuster can move.

[rockNroll]

You probably just didn't get the jam nut tight against the adjusting nut, with the adjusting nut tight against the cap. I tighten my axle till it's "snug" with the axle too far forward and then pull the axle back and get it aligned with the adjusting nuts, then do the final axle nut tightening. This way the adjusting nuts are kinda tight when I'm done. Then, hold the adjusting nuts while tightening the jam nuts against them.

[backinthesaddleagain]

Originally Posted by kkim

how tight did you make the axle nut? after that's tightened down properly, I don't see how the adjuster can move.

Hey Kelly, the adjuster didn't actually move, the 2 nuts backed off then the end cap came away from the end of the swingarm, probably spinning and hitting a sprocket nut which then bent the threaded portion of the adjuster. The axle was 72lbs and didn't move.

[backinthesaddleagain]

Originally Posted by rockNroll

You probably just didn't get the jam nut tight against the adjusting nut, with the adjusting nut tight against the cap. I tighten my axle till it's "snug" with the axle too far forward and then pull the axle back and get it aligned with the adjusting nuts, then do the final axle nut tightening. This way the adjusting nuts are kinda tight when I'm done. Then, hold the adjusting nuts while tightening the jam nuts against them.

Yeah I think I just didnt tighten that one jam nut as snug as it should have been.

[Dredgshadow]

Sorry to revive an old thread, but I thought it was better than making a new one...
Today I adjusted my chain because it was loose. After I loosened the axle bolts I went to the adjuster nuts and they were loose enough that I could move them with my fingers. Adjusted chain and tightened the axle back down and went for a ride. When I got back the adjusters had worked themselves loose again...ugh. So I guess I am going to need new nuts and some silicone to lock them down. My question is, was this a situation that was dangerous? If the axle is properly torqued down, the chain adjusters wouldn't be able to make the rear wheel move any way...correct? I don't like messing around with things that could get me injured or killed so any clarification on this would be awesome.
Thanks

[Motofool]

Originally Posted by Dredgshadow

Sorry to revive an old thread, but I thought it was better than making a new one...
Today I adjusted my chain because it was loose. After I loosened the axle bolts I went to the adjuster nuts and they were loose enough that I could move them with my fingers. Adjusted chain and tightened the axle back down and went for a ride. When I got back the adjusters had worked themselves loose again...ugh. So I guess I am going to need new nuts and some silicone to lock them down. My question is, was this a situation that was dangerous? If the axle is properly torqued down, the chain adjusters wouldn't be able to make the rear wheel move any way...correct? I don't like messing around with things that could get me injured or killed so any clarification on this would be awesome.
Thanks

The torque for the axle is for making a package with the bearings and separators that prevents any bending of the axis.
Yes, loose axis get bent.
The friction against the swingarm is a bonus that normally prevents the axle from sliding aft or forward.
In bigger bikes, that friction may be overwhelmed by the tension that more HP's put on the chain.

Because of that, the adjusters are there for fine adjustment of the chain slack and as a secondary device to keep the axle from sliding.

The two nuts work creating high friction on the threads of each one, so they don't rotate respect to the threaded rod.

Anything that gets loose and could get caught by the chain or sprocket or any rotating part is dangerous.

Those nuts need no locking agent (Loctite), but enough torque.
The normal practice for final torquing is single-hand-squeezing the two wrenches while they keep a small angle respect to each other.

[rojoracing53]

I swap the outer nut for a plastic lock nut on my bike to keep it from ever moving on it's own. Then I push on a vacuum plug over the threads to keep them clean and rust free.

[texasdave]

Long time listener, first time caller -- thanks to everyone who posts their advice and experiences on here, I've learned a ton, and saved a lot of money and heartache. I thought I'd contribute a small solution that worked for me on this chain adjuster problem.

I am my own worst enemy, I put my rear tire on and didn't tighten the adjuster bolts enough, they spun off while I was riding one day and as you all have experienced, I heard the CHANK of that metal cap go flying into the wilderness... but not before it bent the heck out of the long carriage screw of the adjuster.

I drove to the dealer and asked if they had this in stock - of course not - and it would cost $40 to get it in a week... nerp...


How I fixed this cost me about $5, one trip to home depot and using a drill press -- or -- substitute a very steady hand at a good power drill.

Parts you need from Home depot:

1) size M-8, class 10 coarse, 1.25 hex nuts, 5 of them in the pack, plenty
2) size M-8 class 10 washers, lots in the pack
3) size #62 metal nail stopper / blocker thing -- located in the wood framing area
4) size 3/8 black oxide drill bit if you don't already have one, it needs to be able to drill through metal, many bits will.


Once you straighten your carriage screw using a rubber mallet, this fix is as simple as drilling a hole -- however! -- you DON'T want to drill it in the horizontal center. If you drill it in the horizontal center, the nail blocker metal will scrape your sprocket nuts -- the original cause of the problem... So you need drill the hole slightly more towards the chain side so that there is less hangover from the metal nail blocker. You'll see what I mean once you have this in your hand, the nail blocker is slightly wider than the stock black metal cap.

Uh... that's it... Once you have the hole drilled properly, and it's pretty forgiving, you're done. Just pop it on there, put the teeth over the fitting and tighten it up using your new bolts.


Advantages to this I noticed were:

1) replacing stock large bolt with bolts that are same outer diameter is handy, I can use the same diameter wrench to tighten / loosen them... go figure...

2) the teeth of the nail blocker fit relatively snuggly on the outer diameter of the adjuster housing in the swing arm, these teeth are long and don't allow any spinning, even if very loose -- compare this with the stock metal caps that go only in the inner diameter of the housing, once loose the cap will spin and can graze your nuts... ok I finally said it... been dying to say that...

3) the nail blocker metal is quite strong, I tightened the living shizzz out of it just for giggles and it did not bend whatsoever. I think filing the teeth down or bending them inward slightly would be a good idea, less possible hazard in an accident on the track for other riders.

Good luck and ride safe y'all!

d

IMG_20141122_131135.jpg IMG_20141122_133850.jpg IMG_20141122_134013.jpg IMG_20141122_134145.jpg

[csmith12]

Pro Tip: A lil dab of silicone will do ya. /problem solved

[csmith12]

Welcome Dave! And awesome first post, thanks for your take on a fix.

[Motofool]

Originally Posted by texasdave

Long time listener, first time caller -- thanks to everyone who posts their advice and experiences on here, I've learned a ton, and saved a lot of money and heartache. I thought I'd contribute a small solution that worked for me on this chain adjuster problem...........

Very ingenious solution, Dave.

Thanks and welcome

May I suggest less abuse and neglectfulness for that poor chain?

[CZroe]

I'm going to pass this on to my older brother, @texasdave. His classic KLR650 seems to have the same swingarm caps but he damaged one. He was hoping I had a spare but all my swingarm spares are from F-bikes (very different). Thanks for leaving the lurk pit!

[CZroe]

Originally Posted by CZroe

I'm going to pass this on to my older brother, @texasdave. His classic KLR650 seems to have the same swingarm caps but he damaged one. He was hoping I had a spare but all my swingarm spares are from F-bikes (very different). Thanks for leaving the lurk pit!

Looks like my brother bought OEM replacement parts because he didn't get my email about this thread.

Anyway, I think a simple and cheap center punch can help with drilling and a nibbler tool can trim the excess overhang (I use one for PC case modding). Electrical tape can help with the sharp edges.

Thanks again, @texasdave! Oh! I should point out to you that the purpose of having two different sized nuts is so that you can adjust with your under-seat tool kit which has no duplicate wrench sizes.