calling all gurus!!!!

Alright I have a spectre that's been sitting for far too long. I really want to start a fighter build. But in doing so an extended aluminum swingarm is a must for what I'm going for. With the spectre being a shafty I started tear down to see what I had to work with. Here are a few pics of my findings. Luckily I have a 750 sitting right next to it for easy side by side. Upon inspection after removing the ring and pinnion assembly it apears there are only slight differences. The main difference being the output shaft coming out of the side of the case.

My question is this......does anyone know if the final drive out of a 750 might swap out directly for the spectre final drive? If that's the case then I could be in business here. Let me hear your input. Thanks

Close but no cigar.
Just swap engines.
Cases are different.
Way more work to convert than swap.

Nebr_Rex wrote: Close but no cigar.
Just swap engines.
Cases are different.
Way more work to convert than swap.

Internally? Because externally it will work

Are all the holes tapped?
Can you split the cases without pulling the engine?
Should just need to swap output shaft and cover if it fits.

Nebr_Rex wrote: Are all the holes tapped?
Can you split the cases without pulling the engine?
Should just need to swap output shaft and cover if it fits.

All holes are tapped and the covers from my 750 swap right over. I can't imagine the shift forks or anything else being different.

Already a step ahead of you.

I know I'm out of touch, but could someone define "fighter?" Is it intended to be a drag bike for the street? I ask because bikes with extended swingarms, dropped front ends, no shocks etc. (which may work on the dragstrip) don't handle as well as bikes with the stock geometry; so am I correct in thinking the "fight" is a straight line acceleration contest rather than running down a road with curves, hills, etc.? Just curious. Ed

650ed wrote: I know I'm out of touch, but could someone define "fighter?" Is it intended to be a drag bike for the street? I ask because bikes with extended swingarms, dropped front ends, no shocks etc. (which may work on the dragstrip) don't handle as well as bikes with the stock geometry; so am I correct in thinking the "fight" is a straight line acceleration contest rather than running down a road with curves, hills, etc.? Just curious. Ed

Actually almost the exact opposite. A streetfighter is all about handling with modern suspension front and rear. And when I refer to an "extended" swingarm I am mearly meaning that most modern aluminum swingsrms ie...gsxr, r1, cbr ...etc are generally longer than the stock kz swingarm.

Pics explaine better

Thanks fo rthe explanation. If that's the purpose (and I don't doubt you) I guess there are some folks that simply don't understand what makes a bike handle well. I say this because I see folks who say they're building a "fighter" but their pics show Lincoln Towncar length swingarms matched with stubby little front forks so low the bike's geometry is totally screwed up (not to mention things scrape in turns), hardtails or struts (and you know how well that makes a bike handle), and silly wide tires front and back that will not change direction easily - some with tread that belongs on a motocrosser instead of the street, etc. I suppose if the components are well thought out and properly matched a modded bike can handle well. I guess I just haven't seen enough good examples. Ed

BTW, I notice the bike in your example has plenty of ground clearance; much different (better) than some I see that have about 2 inches under the collector.

I will have to agree with you on that one. The one in the pic is one of my biggest inspirations. But I would like the front a little higher. And I have my bobber for a ground scraper.

Actually a streetfighter is a modern sport bike (like a GSXR or CBR900rr) with its fairing removed, duel round headlights and motocross handlebars mounted. This started in England with riders who could not afford to replace their broken fairings.
A UJM, like a kz750 or KZ1000, with the suspention from a modern bike is more like a retro-rod or a superbike replica.
A KZ1000 with a 6 in. over swingarm and struts is a drag bike or a 200 mile a year street bike.

I have started to convert my 79 KZ1000 shaft to chain, I didn't think it was possible until I saw a post on one of my threads on Cusotmfighter.com, a guy named bill posted this....

The Shaftdrive zeds are really easy to convert to chain drive, I have done loads of them. You'll need the following parts.

Chaindrive gearbox output shaft
Sprocket back plate
Sprocket cover and cable clutch actuator worm

Flip the motor upside down, 
Remove the side covers and ignition housing
Remove the bevel box
Remove the lower crankcase half
Take out the gearbox out put shaft, and remove all the gears
Fit the gears onto your new chandrive output shaft
Refit the shaft, and refit the lower crankcase half
Remove the peg that the gearchange claw spring acts on and put it into the hole next to it.
Refit the gearchange claw mechanism into the other hole.
Fit the sprocket back plate
Fit a sprocket
Fit the sprocket cover.
Refit the clutch cover and ignition housing and ignition cover
Refit the Alternator cover

Job done.

You can now fit whatever swingarm you want in there, the other thing you will find is that the swingarm pivot area is much wider on the shafty than on the chaindrive models, this has two beneficial effects, A/ You can fit a wider arm giving you better choice of parts, and B/ you can run a wider wheel without worrying about the chainrun hitting the frame. With a little tweaking the Triumph single sided arm will fit into the shafty frame, although the wheel needs spacing to the right by around 10/15mm.


The cost for the conversion has come to £141 inc shipping I will need to add gaskets, hope this gives you a rough idea of cost. I've gone with a hayabusa swing arm and running gear, this has added 2-3 inches to the wheel base

I look forward to seeing it finished

Reich, where did you get that picture? More info please!