[routine8]

Hey People,

Thank goodness for this forum and others like it . Theyre so helpful and informative.

Anyway, Ive got 2 Ninja 250ex bikes (one for parts), and a problem with the running one. My chain tension changes as I turn the rear wheel when its jacked up. It also does this while riding. It makes a loud rubbing sound when the tension increases every half second (depending on the speed Im going). It seems to me that my front sprocket is messed up or the shaft it is connected to is warped (causing it to go back and forth towards the front and rear as it spins).

My rear sprocket looks fine and my chain is well oiled. I believe the rear wheel is well balanced thanks to the built in measuring kinks on either side of the rear wheel-shaft.

Does this ring a bell loud and clear with anyone? If so, let me know what you did to remedy the problem.... please

ps: anyone think that I should NOT use a haynes repair manual for the ninja 500ex with my 250? Nobody makes them for the 250s :?

 

[2WheelFun]

Hi routine8 and welcome!

Can you see the front sproket and how does it look?

 

[QKENUF4U]

if slack is correct on the chain then it sounds like you basically have a worn out chain.

 

[routine8]

I took off the clutch plate today and cleaned out some gunk there. Looked at the front sprocket: It spins correctly, and the teeth look good, so I guess I need a new chain... Thanks for the suggestions guys.

Anywhere I can find a good deal online?

 

[Knightrider]

Chain problems

Hi:
There will always be a tight spot on a chain when rotating the wheel. When you adjust a chain you should turn the wheel to get that position where the chain is the tightest, then go ahead and adjust the rear wheel to acheive the proper slack at that position. Maybe the chain is just adjusted too tight now and when it gets to its tight spot, its just too tight. Every rear sporcket has a certain amount of out of round runout. I would recheck your chain adjustment again and make sure that your rear sprocket isnt worn or bent and that when you spin the rear wheel, it runs true. If you replace the chain, replace the front and rear sprockets as well. Go to sprocket specialists. www.sprocketspecialists.com

 

[routine8]

I have adjusted the slack on the chain to where the chain is never too tight... but there is such a difference between the tight part and the loose part that I am still feeling it in the ride. I am going to change my chain for sure but I dont want to change my sprockets. The sprockets look fine to me. I dont think they have deformed at all.

Can someone respond to this? I know people recommend new sprockets but I wonder if there is an argument for not replacing them. Has anyone had good luck with older sprockets and a new chain??

 

[QKENUF4U]

unless they are brand new sprockets there will be wear patterns that will wear the new chain out prematurely. you can put a new chain on it and maybe you will get lucky and it will last you a long time, your call.
good luck

 

[rbentnail]

Although I don't have much experience with bike chain drives and wear patterns, in the 20 or so years of heavy equipment & industrial plant maintenance the rule has ALWAYS been: on critical (most important) equipment, when replacing drive chains replace the sprockets. All of them. And if a sprocket needs replacing, replace all of them and the chain.

So: the question is: how critical do you think this component is? Your call.

 

[2WheelFun]

Scenario follows:

You buy only a new chain and still have the problem.

You buy a new chain and the problem goes away.

You buy a new chain and sprokets and problem is gone and chain & sprokets last a long time.

You buy a new chain, new sprokets, and the problem is still there....you buy a new bike. J/K

It's always recommended to replace the chain and sprokets together.