Chain Adjuster Bolt Issue

fyl1982

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So, I've replaced this bolt a few times because when I would torque down my axle the chain adjust would move with the bolt and cause the chain adjuster bolt to bend.

I finally replaced the bolt with a 8mm class 8.8 bolt instead of the stainless steel / weak bolt that was on it. Now it doesn't bend and seems much more sturdy.

The issue I have, is the groove the bolt sits in seems too shallow, like the bolt could easily slip out if something happened. Is there a way I could cut a deeper groove into the frame??? I just have no idea what technique would work for this or the pros / cons. I was thinking a rotary tool with a round diamond file bit or something. idk Suggestions? :shrug:
 
The original bolts had a bit of a point ground on the ends so they stuck in that frame dimple better. Maybe grind the ends of your new bolts that way?
 
Yeah, I ordered some replacements from mikesxs.com... they were pointy but very weak bolts. I'd rather grind a deeper groove so I know they absolutely won't go anywhere.
 
fyl1982;

How much torque are you using on the axle nut? I've been adjusting chains on Yamaha bikes for about 22 years, and never experienced anything like you mentioned. The chain adjuster bracket normally never moves.
 
lol, you'll never get it that tight. I don't know where Yamaha came up with these specs but it's usually just not possible. Just make it tight, good and tight, and align the castle nut so you can get the cotter pin through.

I have the proper 150 lb. torque wrench required for this. I tried to do it. It's ridiculous and just plain silly. Just make it good and tight, and align the cotter key holes. With the key, it can't come loose (much, but that's another story, lol). There's more but I seem to have run out of "stim" (an old "Sand Pebbles" reference in case anyone is interested).
 
I got it to 108.5 very easily. I have no idea what you are talking about it not being possible.

I agree with 5twins. This is one case where you don't torque to Yamaha's spec. 108 ft-lbs is a lot of torque................... way more than what is needed. I only use 76 ft-lbs on my wheel lugs on my car.

I have never used a torque wrench on a motorcycles rear axle. Just as 5twins said, tighten until its good and tight and the castle nut alines with one of the holes for the cotter pin. I've never seen one come loose yet.
 
So... does anyone have an answer to my question about cutting into the frame?

Sure go ahead and grind a larger dimple, for the adjusting screw to seat into. I can't see a need to do that but give it a try and post a pic for us to see.

You could use a portable drill with a small grinding stone in it's jaw.
 
Or find a drill bit about the same diameter as the axle plate and drill the dimple deeper.
 
Not that this has ever happened before but....
one side of one adjuster is smaller than the other three holes, that side of that adjuster has to be on the outside of the sprocket side of the axle closest to the nut. If it's not all kinds of funny things happen.
 
Not on mine, all the holes were the same size as the axle. I actually bought a replacement set from mikesxs.net and the axle size wasn't correct on any of the holes.

I like the idea of the stone grinder bit on the drill. That should work. Thanks! =)
 
On my stock adjusters the axle nut goes to the brake side. The adjuster with the smaller hole only has the alignment mark on one edge. You have to put it on the right side to be able to see it when using the marks on the swingarm to align the wheel.
Leo
 
Then that's different than every other 650 ever made. From day one, they all had the axle inserted from the right, axle nut and small holed adjuster ('74-on) on the left (sprocket side). '73 and older models had no small hole adjuster, both were the same and could be used on either side.
 
I've been having this same issue with my hardtail frame and was thinking about drilling a blind hole into the slots in order to better secure the chain tensioner (this is what Haynes call them but I see a lot of people refer to them as axle adjuster) bolts. I'll drill one hole, then stick a small dowel in it and mark the dowel to use a gauge to ensure the other hole is the correct depth. Any thoughts? Seems like it'll work fine haha

I'm wondering what kind of experience others have had utilizing the stock chain tensioners/axle adjusters with various hardtail frames or kits? I'm running David Bird's straight leg style frame for Yamaha XS650 as sold at Lowbrow Customs. I'm really pleased with the overall quality, but this slippage issue is driving me nuts. There's basically a V-groove cut out for the tensioner bolt to sit in, and I've noticed on the TC Bros kit there isn't a groove, but it is countersunk instead.
 
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I'm just not understanding what is slipping. When I tighten the adjuster bolts to position the axle, the axle nut is semi-tight to start with, when the chain has the right tension I tighten the axle nut. After tightening the axle nut I snug the adjuster bolts against the frame and then the locking nuts.

WHAT SLIPS?

Scott
 
Mr. Two Wheel, I will try your method, but to clarify...

The chain tensioner itself slips when tightening the axle nut because the adjuster bolt slips from the groove/fillet on the axle plate (hardtail, which is comparable to the swingarm fillets on the stock bike). I'll try to upload photos to this thread sometime, but the adjusting bolts, even when secured, do not stay within the fillets. They don't have a good grip.

I definitely believe a pointed bolt will help; however, I also think the fillet groove is too shallow. It's not too hard to tap them back up to their proper position with a mallet once they slip, but this often un-aligns the wheel.
 
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