Hi all,

I have a 2016 ZX-14r that I bought new 13 months ago. The bike currently has about 8,200 miles on it. I recently changed out my front sprocket from the factory 17T to a Vortex 18T. The bike had about 7,800 or 7,900 miles on it at the time of the change. I was worried about changing only the one sprocket without changing the whole set (both sprockets and chain), but I also figured the front wears far slower and the chain has been meticulously maintained since I bought the bike. Within a few days of riding it with the new sprocket I started hearing a loud popping noise when taking off from a stop as the clutch starts to grab in the friction zone. I noticed the chain had loosened up from setting the tension after putting on the new sprocket, so I tightened it back to factory spec. It is still making the noise. The chain has been cleaned and lubed on a regular basis since I bought the bike and it appears to be in good condition.

I currently have the bike on my lift table on a rear stand and have been trying to duplicate it with the front sprocket cover off but I can't. The sprocket nut is still tight, the chain tension is in spec. Am I stuck having to buy a new chain or does anyone have another ideas?

With the 18T front sprocket, the chain is VERY close to the chain guard that wraps around the front of the front sprocket, but I took it off and cleaned it to see if the chain has been hitting it and I don't see any obvious signs that the chain has been hitting or rubbing that guard.

Thanks in advance for any help you can give me!

I'm not sure what the noise could be but a tale of warning. When I had a 86 Ninja 1000 I changed my chain.
Everything was fine until one day I was pulling away from a light. I hear a "pop pop pop' sound then "bang".
Lost all drive. Looked down and there is no chain and oil all over the ground. The chain had broken at one of the inner links, ( I suspect a faulty chain) and took out my crankcase. Bye bye Ninja 1000...
So, take a look at all the links and link pins. See if a pin is migrating out.

Mad

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Did you try duplicating the problem on your table with the cover on? It may be the cover. That thing has a steel plate with rubber damper under it. Maybe the chain is hitting that.

I have found the chain stretches at an accelerated rate any time I replace one part or all of the final drive. That might just be normal wear in of the new sprocket with the old chain.

Sounds like possibly the rear sprocket is seriously out of line with the front. The links are binding on the teeth and snapping into place when the chain is at static tension. After centrifugal force tightens the chain, it engages more smoothly. Just a possibility. Check the axle alignment but I imagine it would have to off by a considerable amount to cause an actual noise. Then again, you do have a larger diameter sprocket on there now.

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It turned out to be just a loose chain. It definitely wasn't WAY too loose, but it was loose enough. I think I have always erred on the looser side when setting the tensions, and I still don't know if it was slapping the swingarm or what was causing the popping noise, but maybe being slightly loose was compounded with the larger front sprocket (changing the chains path of travel) and causing it to hit something it never hit before. Anyway, I found the tightest point in the chain's rotation and set it to exactly 1 inch of slack combined pushing down and then up on the bottom run and no more noises.

Maddevil... that was what I was afraid of! Every time I've ever heard a story of a chain breaking it ended in the case being cracked!

Rook... I'll be keeping an eye on the tension for the next several hundred miles because I saw the same thing you just described... an accelerated rate of loosening up since putting the new sprocket on. But this evening was the first ride since putting the new sprocket on that it made zero noise, so I think I got the tension right this time.

* Last updated by: bcullip on 8/14/2017 @ 6:23 PM *

Rook,

This is my homemade alignment tool. I had the machinist at my work center punch the 1/4-20 threaded rod on a lathe to have a perfectly centered dimple for the trammel points to line up in. The 1" diameter round delrin pieces were tapered and drilled and tapped 1/4-20 on a lathe. One goes through the swingarm bolt and the other through the axle bolt. The tapered delrin pieces center the threaded rod through the 2 bolts. After I set the chain tension, I set the trammel points to the chain side and match the distance on the other side. I go back and forth several times until I'm happy with it. As sharp as the trammel points are, and with everything machined for true center, I swear by this method of alignment. I can't see it possibly being off more than 1/32" side to side. My bike tracks straighter down the road today than it did when I first left the dealership.

* Last updated by: bcullip on 8/14/2017 @ 9:01 PM *

It turned out to be just a loose chain.

BINGO! Saw my reply at 1441R.com? Yes, I've observed my chain bounce and thump/crunch with engine running the rear wheel on a swing arm pivot stand. The rear suspension is open to max and the chain tension is reduced to min. The sprockets don't like that much and I believe it was mostly the front which in my case has always been the stock # of teeth.

Now that I think about it, any bike I have ever braked with hard enough to lift the rear off the ground will make that noise. Same situation--the swingarm opens and the chain goes way slack thumping over the sprocket as long as the rear wheel is not locked. LOL I guess I'm probably not over breaking with the rear!

I found the tightest point in the chain's rotation and set it to exactly 1 inch of slack combined pushing down and then up on the bottom run and no more noises.

That's how I do it. Combine the travel of both top and bottom runs. If you try to measure off of just the top or just the bottom, the chain hits the swingarm before full chain travel both up and down. I normally go for about an inch an a half total or a bit less. Approximately two lbs of pressure. You can get that chain to say whatever you want if you pull hard enough but I think about 2 lbs is the right amount of force to use.

I saw the same thing you just described... an accelerated rate of loosening up since putting the new sprocket on.

Yes, with a new rear sprocket and old front and old chain, I was adjusting the chain every few rides probably 3~5 times before they wore in together.

Thanks for the explanation of that axle alignment tool. I always wondered how those worked. Yours looks similar to some that are manufactured. Maybe I will get one of those now. My rear sprocket has always worn more on the inside. That tool seems like the easiest and most accurate way to get it perfectly straight.

* Last updated by: Rook on 8/15/2017 @ 10:13 AM *

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I recently swapped chain and sprockets and substituted an 18-tooth for the stock 17 front. Rolling around the garage, the chain rattles on the sprocket surround. Evidently there's a little less clearance with the extra tooth. Once rolling, the noise disappears. I imagine a loose chain would have the same effect.

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That's what I was thinking. ..the chain tightens up from centrifugal force and yours must be pulling tighter to the sprocket when you're at speed.

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