Sprocket Tab Washer - again !

[DeadZedDave]

I'm reading the earlier post with the solution of using a grub screw or roll pin to lock the output shaft sprocket / bolt on the early J/Gpz type engine - posted recently. I'm guessing that this is the tried and tested method !! (?) I've just gone to a bit of time and effort to obtain the standard 2 part tab washer / lock washer as a N.O.S. item but can also see these lock washers are obsolete. IS THE LOCK PIN / GRUB SCREW WHAT MOST PEOPLE DO THESE DAYS ??

[Robw]

I use the tab washer system on my b1, and never had any problems, you can reuse it a few times, if you are careful removing it.
On my Lawson and Endurance bike, as they have offset sprocket, I just use loctite and torque them to factory spec. Never had a problem with them either and they both have hard use on the track.
Only problem that I have had, is the bolt recently snapped, but that was after 10 years of track use.
Rob

[DeadZedDave]

Thanks for your reply Rob ! I'll be using the OEM tab washer for now but I am wondering what type of Loctite you use ? If it holds together for race use I'm sure it'll be fine on a road bike. I'm thinking the OEM tabwasher is/was Kawasakis best solution but it seems that new / replacements are becoming hard to get and if theres an alternative tried and tested solution it's good to know ! I also hope that when your sprocket bolt snapped, you were tightening or loosening it and not while you were racing.....its not good when the sprocket falls off when you're riding - all sorts of bad things can happen !!!!! (These bolts are getting hard to get and very expensive as well so if you find a readily available replacement that works, it'll be good to know)
Up until this year I've not had much to do with these "newer type" J engines - I always had the earlier "kickstart" type motors which as you'll know use a big old nut and more normal tab washer to secure the gearbox sprocket - I've never had one of these come loose. Its hard to understand why in 1981 Kawasaki changed the design only to go back to the original system a couple of years later ! Thanks again for your reply. Dave

[Robw]

Hi, loctite 242 blue is what I generally use, have used red in the past for various applications but that is regarded as more permanent.
The bolt snapped coming out of the chicane going into the left hand bend near the mountain at Cadwell. Very lucky by all accounts that it did cause any damage or lock up the rear wheel. Was very confusing when I was twisting the throttle and not going anywhere until I saw the chain dragging on the floor.
Rob

[scott]

I've managed to get one of those lock washer kits, so will go down that route with the offset sprocket rather than the pin/grub screw.

[DeadZedDave]

Hi Rob and Scott....
Thanks once again Rob for the Loctite information, I'm sure it'l be useful in future. I have to say that when I read what happened at Cadwell my blood ran cold for a moment ! Lucky..... I would say so - in the past I've seen so much damage caused when this happens - and not just damage to the bike...
Hello Scott, I'm looking again at your earlier post with the picture of your offset sprocket set up and I don't think the OEM tab washer assembly will fit... certainly not without some modification. The solution with the grub screw or roll pin might be the better solution with the modified sprocket (maybe some Loctite as well ?). If you check out a standard sprocket and OEM tab washer assembly, theres two relatively large holes in the face of the sprocket for the tab washer to anchor into and your offset sprocket doesn't have these. I'm guessing youv'e gone for a quite wide back tyre !! Recollection is a 160 or maybe 170 tyre is about the limit using OEM gearbox sprocket / parts.....

[scott]

Hi Dave, the offset sprocket will be machined to take the lock washer.
Yes, big tyres. It’s a 180 rear and 120 front. It only fits on the rear due to machining work. The wheels are magnesium from Dymag. The hubs are removable and can be machined by Dymag or remade to suit. I had a new hub made and a new sprocket carrier made. This enabled perfect wheel alignment and also perfect chain alignment. It did have a Pirelli Diablo Super Corsa on it. That tyre is 185mm……to big, it actually clears the frame etc but touched the rivets on the chain. Fitted a Michelin PR4 and got 6mm chain clearance. The Michelin actually measured 179. It’s stated to be a 180.
This is the reason why so many builds have clearance issues.
A. The tyre is to wide. Not all 180’s are actually 180. I tried numerous tyres and only the PR4 was exactly as it should be.
B. Most wheels have fixed hubs/sprocket carriers and are not removable to machine. You are stuck with what you get when using OEM wheels.

[DeadZedDave]

Hi Scott, your bike looks absolutely brilliant !
Putting modern/wider radial wheels and tyres on old Zed's can bring many challenges to catch out the unwary. It sounds like you've got it all covered though!! Wheels with removable hubs are a big help, though that means aftermarket / race wheels and +££££'s but as you know, its worth it.
Machining the sprocket to accept the OEM tab washer sounds to me like the best way forward. The Kawasaki design can't be wrong.
I'm inclined to put a bit of Loctite on mine though - just for extra insurance. The later type output shaft with a nut on the end - like the early Zed's - seems like the ultimate solution though - but that's an engine out / bottom crankcase off job.... and thats assuming you can find the late model output shaft.... in good condition. That's all a lot of work for a just in case scenario and I think your plan with the sprocket mods and tab washer will be fine !! Thanks for sending the picture - looks great - take care out there ! Dave

[Al]

Dave, i have changed to the later type output shaft with the nut but a couple of years back i was doing this with non drilled sprockets.
The ZZR sprocket; 'inner flat', wasnt wide enough to take the 'retainer kit tab washer' so i made a simple copy which is a little narrower and cut down the outer edges of the 'bolt head capture plate' to suit.
I didnt use loctite on the thread and loctite, or other thread lock liquids dont appear on the original methodology or on the later revised methodology and i suspect the reason for this is because if you lock the thread to the shaft and the head end of the bolt rocks back and forth every time you change gear the bolt will eventually fatigue. This may take ten years though
Picture of ugly looking approach to not having to drill or tap a bastard hard front sprocket at the very bottom of the page!!!

viewtopic.php?f=7&t=45977&start=120

AL

[DeadZedDave]

Ha Ha ! Get the welder on it ....
Al, thanks for re-posting the old thread - I knew I'd read something about this before ! I too had also thought about making a "modified tab washer..... your pictures are proof it works - if it'll cope with the 5/8 offset sprocket it'll handle anything !
You've mentioned the shorter length of spline on the newer sprockets and I've also wondered if I could use the later tab washer from the J3 and modify /devise a new retaining bolt to allow the splined washer to sit on the end of the output spline and use it to lock the bolt.... or am I just going crazy !
Meantime I'm using the standard tab washer assembly and a narrower wheel....
J3 onward "nut on end of shaft" has got to be the best solution though.... like what you've done.... and put the welder away !

[Al]

Maybe not as mad as you think. The 'nut' fixed, later version has a large hollow recess on the back face of the nut. This is to clear, in part, any excess protruding shaft length.
The ZZR sprocket came with two large (spline to the inside) locking washers. These would be the way the ZZR locks that nut in place.
I used them both behind the sprocket so there was no excess shaft protruding beyond the sprocket face.
So all you need to do is make a bolt with a nut sized head with a recess on the back face and youre in business.
Or take my lazy way out and blow some sparks at it for ten seconds. This was the final incarnation in the saga of lazyness where i had a recessed sprocket with parallel sides so i dispensed with the base part of the tabbed washer locking system and just welded four stubby tabs to the sprocket.

Click pic to zoom.

RIMG0042_zpsa3ad9fe8.JPG (86.21 KiB) Viewed 2454 times

AL

[DeadZedDave]

Thanks Al, Scott and Rob for your replies - all good useful information.
Al, the last picture doesn't display at my end but I think think I understand from your description ! It's probably the simplest way to achieve whats needed if I understand it right.
After thinking about all this I find it hard to understand why, in 81, when Kawasaki was making the big update to its flagship model, they made this design change on the output shaft - the original Z1/Z1000 design was fine and the A3/A4 was already using the longer spline output shaft with internal splines on the tab washer and a recessed nut SO WHY THE HECK DID THET CHANGE ? the 81 on 10mm bolt and washer makes no sense to me ! (it looks like they got the parts from the local hardware shop) When you think there must have been a good few thousand bikes sold before the service bulletin / addition of the lock washer its sounds even more crazy. How did they expect it would stay together ??
Anyhow, I'll use the nice shiny NOS lock washer assembly and if I ever get around to it I'll fit a late model output shaft.
Once again thanks.