A "vertically challenged" question

[drzcharlie]

I bought a lowering link from an inmate on ADV. It is a homebuilt one but it has needle bearings and a bushing and is very well made. Since installing the link I have assumed a rather loud rattling noise on corrugations and holes. Since I have always chosen to "tough it out" and not lower my bike I have never had the experience of using a lowering link and need to sort out the rattle thing, besides I like being able to reach the ground now!

My question Do I need to change the pre-load and damping on the rear shock to stop the rattle? I am assuming the spring is rattling. Anyone have any insight to help me out? I will reset my sag once the rattle is sorted.

Any help would be appreciated and soon please because I am getting ready for a multi week trip.

 

[msmith345]

A lowering link shouldn't cause any rattling, as everything should still be tight. The only thing I can think is that the geometry changed enough that the spring is actually contacting something, which would be bad.

There would have to be no pre-load at all for the spring to rattle on the shock, if that's the case, adding even a bit (5mm or so), should be enough to keep things in constant contact and prevent rattling.

 

[mag00]

I bought a lowering link from an inmate on ADV. It is a homebuilt one but it has needle bearings and a bushing and is very well made. Since installing the link I have assumed a rather loud rattling noise on corrugations and holes. Since I have always chosen to "tough it out" and not lower my bike I have never had the experience of using a lowering link and need to sort out the rattle thing, besides I like being able to reach the ground now!

My question Do I need to change the pre-load and damping on the rear shock to stop the rattle? I am assuming the spring is rattling. Anyone have any insight to help me out? I will reset my sag once the rattle is sorted.

Any help would be appreciated and soon please because I am getting ready for a multi week trip.

I have the koubalink and no rattles. Mine has a grease fitting on the front where the needle bearings are. If you flip it, the zerk could hit the triangle link.

How much did it lower your bike?



Could it be chain slap?

 

[drzcharlie]

It might be chain slap. Here is what I've done so far to find and eliminate the rattle.

1. Took off the crash bars (sound is coming from directly or slightly behind me) to see if that eliminated it. Rode it, Nope didn't fix it.
2. Took off the bash plate and in the process found a slight rattle cause from the plates contact with the OEM mount for the shock link. Rode it, Nope didn't fix it.
3. Checked all frame and engine mounting points for loose fasteners, fractures, or breaks. Didn't find any.
4. Removed side and rear racks. Rode it, Nope it didn't fix it.
5. Removed the new Lowering Link, inspected it found slight side to side play, placed thin delrin washers in the spaces, remounted it. Rode it, Nope didn't fix it.
6. Adjust preload as tight as it would go. Rode it, Nope didn't fix it.
7. Adjusted preload back to original. Rode it, Nope didn't fix it. No worse, no better.
8. Accessed the "secret" rear compartment. Found three plugs there that had been knocking about. Wrapped them with foam sheet and zip tied them. Rode it, Nope didn't fix it
9. Adjusted the chain tighter. Rode it, slightly better but the chain is too tight.

So, I recently went from a the OEM counter sprocket to a 15 tooth, mounted a new rear tire and mounted the lowering link. Too many things to try to negotiate around to find the answer. I didn't see any rubs on metal adjacent to the chain nor on the chain slider (beyond what would be normal.)

What next? Better ear plugs?

Bike is naked right now. I am tired of working on it for the moment so it can sit for a couple of days.

 

[mag00]

Remove new link install stock link, and try again. If the rattle stops, you know what caused it. I looked at mine pretty good just now, the bolt that holds the shock on is fairly close to the link arms.

This may sound basic, but did the rear drive cushions all look OK and go back in?

What about the brake switch wire/clamp that hooks to the sprocket cover? Sprocket bolt tight?

Loud or soft rattle? Kick stand?

My bike has the 14t sprocket and Koabalink, no issues, unless I hit a bump/jump hard, then the chain and kickstand rattle/clunk.

Methodically backtrack, you will find it. Check the easy stuff first of course. On some, the spring on the shock shifts and rubs the center, but I don't know what that would sound like.

 

[Quirky]

Have you had a real good look at your exhaust pipe? Inside pillion peg mount and cross member under fuel tank or heat shields.
Also outside of the box-
I've had 2 frame bolts come loose. The front frame upright in front of the engine and under the oil reservoir.

 

[duibhceK]

So, I recently went from a the OEM counter sprocket to a 15 tooth, mounted a new rear tire and mounted the lowering link. Too many things to try to negotiate around to find the answer. I didn't see any rubs on metal adjacent to the chain nor on the chain slider (beyond what would be normal.)

Sounds to me like a combination of the smaller sprocket and the lowering link, bringing the chain closer to the swing arm and swing arm pivot.

 

[drzcharlie]

Remove new link install stock link, and try again. If the rattle stops, you know what caused it. I looked at mine pretty good just now, the bolt that holds the shock on is fairly close to the link arms. Checked the clearance and just to insure no rubbing installed washers on the outboard sides of the link.

This may sound basic, but did the rear drive cushions all look OK and go back in? Yeah, I thought about that too but they are in correctly

What about the brake switch wire/clamp that hooks to the sprocket cover? In place and clamped tightly Sprocket bolt tight? Torqued to speck

Loud or soft rattle? Loud metallic rattle evident over corrugations and holes Kick stand? Haven't investigated it yet, good thought

My bike has the 14t sprocket and Koabalink, no issues, unless I hit a bump/jump hard, then the chain and kickstand rattle/clunk.

Methodically backtrack, you will find it. Check the easy stuff first of course. On some, the spring on the shock shifts and rubs the center, but I don't know what that would sound like.

Thanks for the ideas, I will check the stand tomorrow.

 

[drzcharlie]

Sounds to me like a combination of the smaller sprocket and the lowering link, bringing the chain closer to the swing arm and swing arm pivot.

Thanks, I am beginning to believe this is the case as well. However a good friend has the same bike, same combo of parts and is not experiencing the same noises.

 

[drzcharlie]

Have you had a real good look at your exhaust pipe? Yes, it is tight and in place. Inside pillion peg mount and cross member under fuel tank or heat shields. All good and tight
Also outside of the box-
I've had 2 frame bolts come loose. The front frame upright in front of the engine and under the oil reservoir. Motor mounts are the first thing I checked. All good

Thanks for the insights, I continue to ponder what it is. I am leaning toward the combo of lowering link and smaller sprocket causing chain slap.

 

[mag00]

Charlie, washers will not stop the clatter, if it is a bore diameter issue, Like a hitch pin, it will rattle if loose.

If nothing shows up on visual, I would change the link back to stock.

Got pictures?

 

[duibhceK]

Charlie, washers will not stop the clatter, if it is a bore diameter issue, Like a hitch pin, it will rattle if loose.

The shock is almost always under some load. If it would a diameter issue I'd not expect a rattle put maybe an occasional clonk when hitting a bump or a pothole.

 

[mag00]

The shock is almost always under some load. If it would a diameter issue I'd not expect a rattle put maybe an occasional clonk when hitting a bump or a pothole.

That is true, the shock spring is always under compression. It is the rebound, the time it takes to transition from compression to expansion that will cause the rattle, between the shock and rear wheel.

If you remove weight off of the rear fast, the shock will slow it, that is why good shocks are adjustable on both sides of the action.

Since my bike is in the air, I went out and checked. I put a shovel under the rear and jiggled.

The top mount of the aluminum triangle link is loose on mine. The bottom of the shock bolt and the lowering link bolts are solid, but I do get movement on the top mount bolt of the triangle that hooks them all together.

When the bike is in the air, the shock is fully extended. Easy enough to pull apart, so I guess I shall go check that top link bolt and see what is going on.

 

[mag00]

Popped it apart, not happy, but caught in time.

Seems the rear tire dumps dirt and sand on this suspension link and the sand is getting past the seals.

I found sand and grit inside the needle bearings, and minimal grease. An extended rubber flap from swingarm down can resolve this issue. Time for the rest of you to pop this apart for inspection. Easy enough, get the rear tire off the ground and easy as pie.

Time to pull the swingarm bolt also.

 

[drzcharlie]

Charlie, washers will not stop the clatter, if it is a bore diameter issue, Like a hitch pin, it will rattle if loose.

The washer was to take up sideplay. The bolt fits very tightly in the bushing.

If nothing shows up on visual, I would change the link back to stock.

Got pictures?

 

[drzcharlie]

Magoo is right about that top bolt, mine was in similar condition. I put a piece of rubber belting in front of it to keep crap from getting in there.

By the way, I think I have my rattle sorted. It was my bash plate positioning. Since the lowering link changed the angles of the triangle coupling the chain was hitting it on compression. I got to looking the bike over again as suggested by Magoo. It was then that I noticed that the inside edge of my chain (outside running portion) was shiny like it had been buffed. That led to my figuring out the following:

I will ride in a bit to see if I have it sorted for sure.

 

[mag00]

Glad you got it sorted out. I want to thank you for the topic, I got to looking at my bike and can prevent some premature wear down the road. I'm going to go ahead and pull the shock out completely, and see if this one I have from a Honda will go in. It is a bit shorter, and a shorter action. Who know, might get lucky. It has two way dampening control.