Kawasaki Ninja ZX-6R Forum banner
1 - 6 of 6 Posts

·
Registered
Joined
·
481 Posts
Discussion Starter · #1 ·
This may be mostly for riverszzr, but everyone else is welcome as well.

This year I have changed the chain and sprockets on 3 bikes. They were my 98 ZX6R, 2010 Bandit 1250 and 82 GS1100E. I had not touched the chain set on any of these previously. On both the ZX6R and the GS1100E the countershaft sprocket nut was loose and only being retained by the bent tabs on the splined washer. This was rather disturbing to me as that is close to a Jesus nut on a motorcycle and losing it at speed would be a mess with serious injury and damage potential.

My question is, how common is this? I have only changed a couple other chain sets previously and on both of those the sprocket nut was tight as it should be. If it is a common thing then I am going to start checking them on every used bike I buy from this point on.


Mark
 

·
Registered
Joined
·
14,626 Posts
More Rivers zzr than I, most people have to be smart enough to understand what the risk is; but you shouldn’t trust them to have done it right.
 

·
Registered
Joined
·
273 Posts
I remove the Sprocket cover and check Front Sprocket Security on EVERY Service I carry out and have done for years, I've lost count how many have been loose !
The majority of this you can put down to Folks having no clue what their doing or the implications of carrying on regardless !!
 

·
Director of Moderation
Joined
·
7,524 Posts
I've only seen that happen on a 400 so far, when I torqued the nut on, but forgot to put the washer in first (the one that you bend over a flat side of the nut). It was on a race bike and during the first few sessions on the bike, the nut came off completely and got lost somewhere on the track and the sprocket worked its way out enough to where it fell off the splines so it wasn't being engaged anymore. Not really a catastrophic failure by any means, more of an inconvenience.
 

·
Registered
Joined
·
8,243 Posts
A typical year for me.... I don't even install a dozen chain and sprocket sets and I can't remember ever finding any loose in 40+ years (when they came in for this service)

that said...... I have had bikes come in with the sprocket off the shaft enough to not engage the splines (nut missing, or nut wedged in the greasy grime in the sprocket cover) so thus the bike would not self propell any longer
I have also seen numerous bikes (several dozen) with the clip master link missing and only the plate sitting there by itself holding on......... maybe another dozen or two where the chain was broken- usually at the master from failure but not always
and then a few times I have found (on the old style, shouldered sleeve with 2 bolts into the sprocket) the bolts to be missing or very loose or one missing etc) during some routine service

So Sadly I would say it is a little more common than one would really hope or like............ but by far the vast majority of bikes that I have ever had to get the c/s sprocket nut(s) off of, they are way overtightened or rusted on, or loctited or in some way shape and form - it is clear they are never coming off without some herculean efforts (ie...... 300ft/lb air gun)

That said, only a couple engines have been slapped hard enough by the chain coming around the c/s to casue case damage, and only once did the chain wrap itself around the rear sprocket carrier and swingamr and skid the back tire to a stop, the majority of the time the chain just flies out the back and snakes down a road to astop behind you as you coast powerless over to the side of the road........ So I do not view it as much as a huge crashfest safety issue as some make it out to be, but there is that potential for sure

But yes if done correctly this should never happen
It is one of the numerous things everyone who buys a used bike should go over with a fine tooth comb before riding much, like every nut and bolt and fastener and all the fluids etc....

Last night I just had a pretty new CB500x come in with only 10k on it get a replacement chain for the reason stated of the original being kinked, rusty and overly tight (guy only owned it about 100 miles.... previous owner installed a +1 on the c/s) So I did pull the cover and check the c/s.... the bolt that holds the c/s sprocket in place was missing!! I think the only reason it stayed together was becasue the chain was so overtightened and it was also running crooked in the direction to pull the sprocket towards the engine (rear wheel aimed right)

today a versys650 arrives with just under 12k for a tune up and tires, a quick look and his chain is all rusty, kinked and crooked too........ coincidence???
 
  • Like
Reactions: KevA

·
Registered
Joined
·
481 Posts
Discussion Starter · #6 ·
Thanks for the replies, gentlemen. It seems I am not alone in seeing this happen a number of times. This has convinced me that I will be pulling the cover and checking the sprocket nut every spring when I do the first oil change of the year.


Mark
 
1 - 6 of 6 Posts
Top