1977 z1000 a1 - modifications

Hi All

I am in the process of stripping and rebuilding a 1977 z1000 a1 and would like to get some ideas on modifications to make her better through the twisty bits, braking etc. Some of you have posted some cracker pics of some that are dead set the ducks guts so I need to find out what bits have been used or what options there are. I am not worried about keeping her completely original but dont want to make any changes that I cannot reverse if I chose to bring her back to standard some day and I def dont want to lose the z1000 look. I want to keep the spoke rims but would like to widen the rubber on the road.

Waddya reckon?


cheers
Rob

there are a few standard things you have to do to these old girls to get them handling well..........and some of the mods are not really possible to 'return to stock'.......

#1 - Weld up some braces to the frame under the tank. You need 3 braces that triangulate in the vicinity of the ignition coils. I will scan up a picture from one of my Jap performance cattledogs, it has all the locations marked clearly.

#2 - Frame brace welded up underneath the header pipes, across the frame tubes.

#3 - Gussets welded into the frame near the swingarm pivot, either side. These welded additions tie the frame up nicely, and just about get rid of the standard kwakka hinge in the middle.

#4 - Fit progressive or Hagon springs to the front end, with new seals. Run 15W oil as a starting point. Lighter if you use the bike on the track, heavier if needed, for road use. Fit a fork brace if you can find one - these help a lot.

#5 - Fit new swingarm pivot bearings. A braced swingarm is also a great idea, you can add bracing to a stock one, or use a GSX1100 swingarm with special YSS shocks. In any case, fit some good rear shocks, IKON are OK, so are Hagon. YSS are great as well, a bit more expensive but excellent quality.

#6 - Use good-quality tyres, make sure the wheels are balanced properly, and string-line the wheels for perfect alignement. This last step is the most overlooked, but the *most* critical if you want your bike to steer properly.

That is enough of a starting list. Do all these mods, and your bike will handle way better than it ever used to.....

Thanks Gos

Sounds like the front end is pretty straight forward and shouldnt be too much of a problem, do you recommend steering damper?
The pic for the frame bracing would be much appreciated.
Re the swing arm; Which would be the best way to go so that I can widen the rim and can you tell me how wide I can reasonably go?
While I am playing with the rear end is it worth changing the 630 chain and sprockets, I think you can get a 530 conversion kit?

Questions .. questions .. questons, sorry Gos I hope you dont mind but I figure is better to ask before I have a shed full of bits .. oops too late. I have a set of usd forks from my old zx6rr that I thought about using at one stage there but figured I wouldnt be able to keep the spoke rims, plus worried about altering rake/trail and creating a nightmare!

cheers
Rob

Hey Rob

Sounds like an interesting project. One piece of advice though, the moment you hear the phrase " visit the 4th dimension" from Gos....run man...run like you've never run before.

Good luck with it, Gos is your man

Cheers

I reckon leave the rims the width they are, unless you're going for some sort of fat tyre look. Fat tyres will upset the handling and slow you down, so stick with skinny tyres and get some good rubber on there instead.

..... Gos I hope you dont mind but I figure is better to ask before I have a shed full of bits ....

it's all good Rob, this is what I do

....the moment you hear the phrase " visit the 4th dimension" from Gos....run man...run like you've never run before....

Run...........*straight* to the 4th Dimension. The home of all good kawasaki mods

.....Fat tyres will upset the handling and slow you down, so stick with skinny tyres and get some good rubber on there instead....

I have a 160 rear tyre on a z750 frame........it handles OK - but there are definitely trade-offs with steering when you fit wider rubber *and leave the other steering dimensions stock*. (those fat tyres on Billy's LC have scarred you for life haven't they mate ).

What you need to do is fit a set of z650 or z750 triple clamps to your Z1000 - these bolt straight up, use new tapered bearings - and you immediately get a 10mm reduction in trail, which helps sharpen the steering up quite a bit. You can then use over-size rear tyres without having too much impact on steering. It also helps to run slightly longer rear shocks, which steepen the head angle a bit - this also helps bring back the small amount of sharpness you loose when fitting fat tyres.

A 530-conversion is pretty easy, but I have never seen a 'kit' for this. What I do is use an FZ750 (85-86) model front sprocket, its 530 pitch and comes in 15, 16 and 17 tooth sizes. You need to fit a 2mm washer behind the sprocket, to space the sprocket away from the transmission cover bolts.

A ZX9R (B) model rear sprocket will fit straight up to a Z1000 sprocket carrier. It is also 530 pitch, but these don't come in the OEM 35-tooth size that the old 630 sprockets used to - the lowest is 38 teeth. If you gear it using 17/38, that is almost the same as 15/35 - you will need a longer chain in 530 pitch. This allows you to use the standard rear wheel with a 530 conversion. it is no good if you want to fit a wider rear wheel, you need an off-set sprocket for this.

If you have enough money, you can re-lace the stock hubs to a 4" or 4.5" aluminium rear rim. There is no point going wider than 3" on the front, as this will allow you to fit a 120/17 front tyre in any number of compounds.

If yoou want to fit a ZX6R front end, all you need to do is press out the old steering stem from the ZX6 lower triple clamp, and press in a Z1000 stem. There will be a fair bit of change in geometry when doing this mod - its not one I have done before, but heaps of punters do similiar mods, so it must work OK.

Good luck with this project, don't worry about asking questions, if I can help with advice I will.

... (those fat tyres on Billy's LC have scarred you for life haven't they mate )...

Yep, give me skinny tyres on an old dunger any day

Hmmm fourth dimension, isn't that the place you go after a few/several sherbets

I found the 530 kit on Fleabay, they are about $130ish plus post and have a choice of ratios.

Have been kicking this project around in my head for a while and am thinking that because this is my first shot at an "old dunger" I will try and keep it simple and go with keeping the bike stockish for the time being. I think that I have most of what I need so will strengthen the frame, forks, swing arm to start with and go from there.

I would like to have a shot at building something more special but will have to get rid of either the zx14 or the zx10 to finance. Maybe after this one .......

Found this on ebay uk. What interested me was the front brake conversion off an FZR 1000. Any thoughts? Motor sounds interesting too but I am not even going to think about the "go fast bit" and until I get turn and stop right.

http://cgi.ebay.co.uk/Kawasaki-Z1000A1- ... 43a4b8b0b5

I got into this back in the late 70s.
Gos pretty well covered it.
I did the frame mods he's suggested, plus taper bearings in the steering head instead of the crappy ball bearings (made a huge difference), plus thicker engine mounts (the brackets). Someone also suggested using a thicker bolt through the front engine mounts, so it fitted nice and snug.
I got the swingarm modded with a section added between the forks (rectangular steel box), and a length of steel added the length of each fork.
Now, I'd just fit a decent (modernish) swing arm, unless you want to keep the standard look.

Actually, have an article back from the early/mid 70s about frame mods...in Two Wheels, I think.
If you want, I could put it up here, unless it's an infringement thing.

Thanks Paul

that would be great, when I get the schematics from Gos all I will need to do is find a decent welder who has done this type of stuff before. there is a guy here in goulburn who is a bit of a legend at this so might try him out first. I suspect I will have to sell a kidney though.

Just figured out how to post pics ...yeah I am a tad slow but ya get that

I was going to post a pics of the big girl but have to figure out how to shrink a pic so will do that when I have more time. Anyway the bike is now in bits and am about to clean up the frame and get some work done, I have found some info on where the gussets etc go on the frame. This one is from a Jap website

This one from a Jap website

frame brace 2.png (210.38 KiB) Viewed 13924 times

and this from a pommy rebuild

pommy one

frame brace 1.jpg (76.33 KiB) Viewed 13924 times

there are plenty of similarities but a couple of differences. the Jap one has a rod across the rear of the two cradles and has no gusset at the top front of the triangular section just under where the front of the seat would be like the pommy one.

Does it matter which one or are there more better ways to go

that top photo is the same one I have in my Jap catalogue of Z1 goodies - you must have gone to the same website !

As far as the bracing is concerned, the Jap picture is the best, although in the real world, you will find that there won't be a great deal of difference between that bracing, and the way that the Pommie frame has been braced up.

The most important bit is the bracing up between the top 3 frame tubes, the additional cross-brace between the front 2 frame loops (this should sit just under the header pipes) - you can see its a lot higher in the Jap picture than the pommie frame. be careful with this one, it has to be in the right spot so you don't foul the headers. The bracing at the base of the triangle near the swingarm pivot is also critical.

The next most important addition is a braced swingarm - you will be stressing the swingarm a lot more once the frame has been tightened up. It will make a huge difference again, once you brace the swingarm.

Engine mounts should also be replaced with 10mm aluminium plate. You should be able to knock these up yourself. Fitting oversize engine bolts is also highly recommended - the standard ones have a shitload of slop in them, and if all the bolts are a really nice snug fit into the mounts, this basically makes the engine a semi-stressed frame member.

Get some good Progressive fork springs as well - these help tidy up the response from the front-end.

With all these mods, your old Zed will handle shitloads better than a stocker. I did everything mentioned to my old 1980 Z1000H prior to racing it in Forgotten Era back in 2001, and the old girl was good for about 1'50 flat around the Creek, and could peel into T1 at around 170kmh without any headshake or weaving - nothing at all - just nice and straight ! On normal roads, it still tracks really straight over just about any surface, no more speed-weaves once you get up over 200kmh, of course you need good wheel alignment as well, otherwise it will still weave at speed.

This thread shows some pretty extensive bracing on a '78...http://www.zx-10r.net/forum/showthread.php?t=98274

Gos, this was the thread i mentioned this arvo.