drive sprocket LOCK NUT. missing!

[redmistracer]

G'Day fellow FZ riders. My 1st post is a question

I dropped my bike last sunday. Due to the Lock nut on the drive sprocket coming loose and falling off.
Lucky for my daughter and I it was a slow speed left hander, Top of Mac pass NSW. chain wrapped around swingarm and rear sprocket locking back wheel and highsiding us at about 45k's, low speed high impact.

My question is. Has anybody had this happen or heard of it.
Ive since been told by a mate who owned an FZR600 he had this happed twice. and it may be more comon than we realise.

The lock nut is not usually in my check list.
Ive been racing for a rew years and never had this happen befor.
Changing sprockets for diffrent tracks you notice things like that!.

Oh and i am looking for a new engine case. The chain took a peice out of this one

Regards Tony.

 

[ozzieboy]

G'Day fellow FZ riders. My 1st post is a question

I dropped my bike last sunday. Due to the Lock nut on the drive sprocket coming loose and falling off.
Lucky for my daughter and I it was a slow speed left hander, Top of Mac pass NSW. chain wrapped around swingarm and rear sprocket locking back wheel and highsiding us at about 45k's, low speed high impact.

My question is. Has anybody had this happen or heard of it.
Ive since been told by a mate who owned an FZR600 he had this happed twice. and it may be more comon than we realise.

The lock nut is not usually in my check list.
Ive been racing for a rew years and never had this happen befor.
Changing sprockets for diffrent tracks you notice things like that!.

Oh and i am looking for a new engine case. The chain took a peice out of this one

Regards Tony.

Yikes! Glad you and your daughter are OK mate. Only similar thing I've heard of are broken chains. If it's torqued on there correctly, and the lockwasher is folded up, I can't even imagine it turning. Is it a new bike? If so I'd be giving your dealer a call.

Oh, and :welcome: aboard mate. A shame it couldn't have been under better circumstances for your first post.

If this is common though, you've come to the right place to find out.:thumbup:

 

[muck_mahone]

Glad you're ok Tony, I've never heard of a lock nut coming off, my old yzf600, trx850 and my current fz6 all have nylon lock nuts, without the locknut washer. I think it's more likely they weren't torqued properly last time the sprocket was changed. I can't remember ever seeing a nylon lock nut come off, in any application.

I'm thinking about getting my daughter on the back now she's turned 8 ( I think thats the youngest the laws allow), how do you go about finding proper riding gear for young one?

Maybe check ebay for covers, here's one
YAMAHA FZ6 ENGINE SIDE COVER 2004-2006 (eBay item 330409597503 end time 24-Feb-11 12:05:33 AEDST) : Cars, Bikes, Boats

 

[redmistracer]

Sorry. Daughters are 22 & 19 they both enjoy being on the bike although 19 is keen to get her own bike. Even after her highside.

Fz is an 07. It did the FZ cup in formula xtreme. still has all the track gear in it.
Left set up as cafe racer style with clipons and rearsets etc. has no steering lock with clipons. very hard to do U turns, try not to do any!.

 

[Pauly_V]

Your second post makes me think you left the locknut loose. ??

Glad you and your daughter are alright.

 

[segue00]

I remember a drive sprocket locknut recall back in 2005/2006.....

 

[Hoshiko]

First, glad you and daughter are ok.
Second, cafe racer fz6? and no pictures:spank:
Third, :welcome:

 

[redmistracer]

Your second post makes me think you left the locknut loose. ??


G'Day mate, It crossed my mind also but ive been racing for long enough some things are allways double checked. ie brake caliper bolts(lock wired), axle nuts and depending on changes to gearing rear sprocket and brake disc bolts.
I also place a dot from a white marker pen on nuts and next to them on non moving part as a quick visual check. If their not side by side then I check them.

This is why its caught me by surprise, Its not a component ive had problems with.

When im able to get it back on the track/road I will be taking extra steps to mack sure this never hapens again. and making visual checks easier too.

 

[OZXJR]

I've never heard of a lock nut coming off, my current fz6 have nylon lock nuts, I can't remember ever seeing a nylon lock nut come off, in any application.

My '76 Z1000 had a nylon lock nut ,it didnt come off but it did undo itself almost to the end of the spline and the sprocket moved off the shaft resulting in no drive.The nylon in the nut looked like it had disintergrated ,I have never used a nylox nut on a drive sprocket again.

 

[afpreppie04]

I'm not sure if the Australian FZ is different, but I just changed out my sprockets and chain last week and the drive sprocket was held on with a folding washer and nut, not a nylon locking nut. It still had the original chain and sprockets on, so I am assuming it was the OEM nut/washer, unless there was a recall of sorts like segue00 mentioned.