10MPH Knock???

[belrix]

While riding today I noticed a strange noise; at about 10 mph under mild acceleration I am hearing a knock, just a single knock. If I accelerate harder I still hear the knock followed by a few softer knocks. Once the knocks happen I don't hear them again until I stop and start off again.

Once moving above 10MPH I can't reproduce the knock. I have tried abrupt on and off throttle changes, upshifts and downshifts, and hard braking.

Any idea what the knock could be? My chain is at the loose end of the specified range and has 10,500 miles on it.

Thanks for any ideas, suggestions and advise; I'm a motorcycle newbie.

belrix

 

[Beemerphile]

Drive chain?

 

[belrix]

Drive chain?

Too loose? Stuck links? Just time for a new one?

I will tighten and lube the chain tomorrow morning and see if that helps, but I'm guessing it is time for a new chain and sprockets plus tires!!!

 

[L.B.S.]

I would put the bike up on the center stand and with the bike off, rotate the back wheel around several times. Look/listen closely at the chain, and rear caliper while doing this. Try to wiggle the wheel back and forth (carefully, so as not to tip the bike off the stand of course) and see if there feels like any freeplay. Check to make sure the rear caliper is not moving ie: loose or missing bolts, or not properly slotted onto the locator tang, on the inside of the swingarm.

If all that produces no discernable results, then maybe undo the plastic front sprocket cover, and see if there is too much play with the front sprocket on the countershaft splines. Note- for some curious reason, Honda has a quite a bit of slop in the fitment of the sprocket on the splines (same as my CBR125R) so it might be tough to determine how much is "too much", but I think if there is much more than there should be, you will be able to tell.

It's probably just the chain needing to be replaced, though. Good luck!

 

[belrix]

Thanks for the replies! I will do all of this in the morning. I was hoping to get the chain, sprockets and tires through the winter and replace them in the spring.

I hate to say it but my NCX might be out of commission for awhile the motorcycle fund regenerates.

Belrix

 

[Wcmike]

Same thing happened to me. No kinks in the chain when I examined it. None of the links seemed tight but I replaced it and the sprockets anyway and haven't heard it since.