chain slap?????

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skychair

New Member
Dec 9, 2013
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I thought that I had rubbed my rear tire against something, but appears the chain is the culprit.
Anyone know why this would suddenly happen?
Chain to loose?
Anything to worry about?
Anybody have a suggestion...........
 

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2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
Rear wheel centered and axle nuts tight? Rear sprocket running true with no wobbles? Are the drive and driven sprockets aligned?

You might also want to lubricate that chain. Even if it's just surface rust on the side plates, if they're rusty the rollers and pins might be dry too. A dry chain will run rough and could cause "chain slap".

Have you tried running without a tensioner? It looks like that spring thing is about maxed out. You could probably remove a couple of links.

Tom
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
7,266
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Los Angeles, CA.
Those spring loaded chain tensioners aren't all they're cracked up to be... when you let off the gas, all the tension goes to the bottom side of the chain & the top part flops like crazy!! :(

The best solution for a smooth trouble free chain is to use a hub adapter (because the sprocket spins perfectly true & keeps the chain from bouncing all over at higher speeds), & make sure both sprockets are in line with each other...
As for the chain tensioner?, I would rather use the stock tensioner than one of those spring loaded ones any day of the week! ;)
 

2door

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Sep 15, 2008
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Littleton, Colorado
Those spring loaded chain tensioners aren't all they're cracked up to be... when you let off the gas, all the tension goes to the bottom side of the chain & the top part flops like crazy!! :(

The best solution for a smooth trouble free chain is to use a hub adapter (because the sprocket spins perfectly true & keeps the chain from bouncing all over at higher speeds), & make sure both sprockets are in line with each other...
As for the chain tensioner?, I would rather use the stock tensioner than one of those spring loaded ones any day of the week! ;)
Ditto: The very best option is to not use any tensioner but some frames require them.
You don't want the chain to loose its tension at any time. The spring tensioner allows slack and that's what causes problems. They're more of a band-aid that actually taking care of the real problem which is improper chain/sprocket alignment and chain tension.

The rag joint sprocket adapter will work but it takes careful set up and installation. If a builder doesn't take the time to do a rag joint right then an adapter is the best choice.

Tom
 

Kioshk

Active Member
Oct 21, 2012
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Connecticut
Eh, in my experience, it's the nature of the beast. I've actually spread axle-grease on some of my fatter tires in the past to assist in the tire "break-in" period. I use 29x2.125, so the fatter ones have a tendency of impinging on the drivechain-domain. I have actually gotten into the habit of respoking my wheels to allow as much clearance as possible on the left-side. In any case, I use a dirt-cheap but surprisingly durable tire...it's an NGK Mountain bike one of the aforementioned size. Their trends are too soft, and will wear off quickly, but their underlying rubber is hard and durable. My chains eventually carve cheese-grater grooves in the left-side of these tires, and all is well. Ditto on VMB's comment about the spring-loaded tensioners not handling deceleration well. Best not to use white-walls on these filthy beasts and resign yourself to warts and all.
 

crassius

Well-Known Member
Sep 30, 2012
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a too-loose chain will always move toward the tire when making a left turn with the throttle backed off - a good tensioner will allow you to keep it tight enough to limit that travel
 
Sep 4, 2012
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America's Hi-five
Mine has done the same for many miles, I was nervous about it but it never got any worse than what you show. I have a standard tensioner. The only thing I can add is that it is worse if my spokes are not nice and tight. It barely shows up on my black tire with the red stripe. In fact, it never even wore any of the red off yet, just small areas of the rubber flashing stuff.
Is your bike wet in that pic or are you leaking premix on your bottom bracket?
 
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skychair

New Member
Dec 9, 2013
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Rear wheel is centered and tightened down, I'm running a 2 piece sprocket adapter, and all looks true.

I cannot remove even 1 link because I have vertical drops with near zero adjustment.
I'm thinking of welding in horizontal drops ....any thoughts on this??????

I have always worried about the stock tension er falling into the spokes, thats why I went with the spring loaded one, which was highly recommended, I think here and on other forums.

I did notice that the new tension-er rode a little rougher than the stock one.

What fix is recommended to prevent the stock one from falling into the spokes?????
Thanks for the replys, I have reinstalled the tension-er that came with the kit, as soon as I clean the rear whitewall I' ll see what happens.
Ron
 

crassius

Well-Known Member
Sep 30, 2012
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either just go with the standard tensioner (mounted securely) or drill a hole in the standard tensioner to attach a rod to clamp it to the upper leg of the rear fork
 

align 670

New Member
May 28, 2014
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Claremont,california
I dont know if this has been done, I dont use the chain tensor. I remove the backside frame mounting threaded inserts and put about 4" ones. I put nuts on next then the standard mounts on the frame. I break the chain to the proper length and tighten the extra nuts against the frame mount bracket to get the right chain tension! So the engine is moving forward as I tighten the nuts, to the desired tightness. Enjoy!
 

miked826

New Member
Aug 6, 2011
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Los Angeles
I thought that I had rubbed my rear tire against something, but appears the chain is the culprit.
Anyone know why this would suddenly happen?
Chain to loose?
Anything to worry about?
Anybody have a suggestion...........
I have a suggestion. Get the rear sprocket as far away from the tire as you possibly can. If you have to use washers as spacers on the sprocket bolts then do it. Then push the engine left to line up with the newly spaced sprocket. If you have to use washers as spacers for the motor mount shift then do that as well.

Basically you need to get the chain away from the tires sidewall or you risk possibly eating right through it while you're motoring down the road. I can't imagine that would be a pleasant event if it did happen. Chain vs Tire? My money is on the chain every time. LOL
 
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2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
Miked826, how would you go about pushing the engine to the left ?

I've had to offset engines for fat rear tire and frame clearance but it requires custom engine mounts. You can't tilt the engine, or shouldn't, so how do you "push it to the left". Just curious, sir.

Tom