'76 KZ900 (ZRX1200R) Build

Let's hear from the drag racers. How many launches are you getting om a rear wheel? I don; think it will be a problem. I didn't get a chance to read the article linked yet but do the new sportbikes have cush drive? That would be telling.
Wayne

I plan on riding this bike quite a bit as after I do this much work, I want to ride the blasted thing! Besides I have to practice not getting my leg caught in the belt drive! :woohoo: I have a lead on a Ducati cush drive assembly that might be adapted to work with the HD hubs. I am waiting on the seller to provide me some dimensions off of it. We'll see how it turns out.

I grew up on enduros that didn't have a cush drive, and never really noticed a harshness that was above the regular NVH that comes from riding a street legal dirtbike. I do understand that it can cause premature wear on the driveline, so I probable should have one. I tracked down a cush drive kit from HD, and it is fairly expensive. The one down side to it, it fits in the center of the belt drive pulley so I worry about how wide it is. If I bought it, I would have to machine the pulley off of the center disc and then create the sprocket holder.

Cory

So I have made a score on Ducati cush drive pins/hardware. I have my design sketched out for a cush drive that will bolt onto the HD hubs. I am going to end up using Suzuki SV1000 rear sprocket. So it should be set up well. We'll see once more parts start to arrive....

I also found Ebay caliper spacer brackets and ZX11 rotors... Can't afford them right now, but hopefully soon.

Cory

PM sent mate, i dont know where my last post dissapeared to?

As sales solicitations are off-limits except as permitted in Classifieds (consumer-to-consumer transactions), a topic has been created in the For Sale forum, entitled "GT1000 wheels," to where the related posts have been relocated.

Good Fortune!

Ok, so it was like Christmas today. EBay packages galore. So first off, the question can be answered what are the dimensions of Narrow, Standard, and Wide HD hubs.... They go from 4", 5" and 6" from side to side.



So now you can sleep at night....:blink: It looks like the narrow will be the one for the front. Something interesting though, the narrow hub was an earlier hub that had the roller taper bearings. The hub flange was wider, and it was the exact same as the ZRX rotor hub bore! Now the bore for the bearing race will need to be taken out from 45mm to 50mm so I can use standard ZRX bearings.



The other 1/2" spacers showed up, but they are for the 2000+ HD hubs....So I probable won't get around to using them....:sick: I'll end up buying some others.... IF you add them to the standard hub, it makes the wide hub version.




Also my 22T pulley came from across the water.....



I also have spoke kits coming and once my bonus check gets here, I'll order my rims from Buchanan's....

Cory

So I got a little time to play with the bike on Sat. My new '77-'83 Disc spacers got here and fit the hubs and the ZRX discs perfectly. I just need to cut them back on the lathe .059" each to get the disc to disc spacing correct. I will have to mill them with notches for the speedo drive collar.



Then I moved onto trying to make some headway on the belt drive alternator. I first got my shaft drive bolted up, and marked it for the cover plate and seal thickness. This then told me how far I had to cut the stock cover back. Taped it off, and used my cut off wheel.




I will bolt it up to a board and put it in the mill to finish cutting and truing the cut. So then I mounted up my stock carbs to verify the alternator to carb clearance. I located the pivot bolt hole on the drag plate and drilled it. I used aluminum tubing as spacer, but will probable have a solid rod that is drilled and tapped at both ends, but this tubing is easy to cut and change for mock up until I am happy....






Now it looks like I have to bring the carb set forward of the carb bowl in order to give adequate leg clearance.



Then I cut my new pulley up to get the fitment for the shaft. I ended up cutting a few thousandths more than I should (boring bar mis-calc..oops...) and it was not quite the drag fit I wanted. My brother helped me out and used his gunsmithing bedding compound and now it is a tight fit.





So now I have to order up some plate and tubing to make hub spacers and my cover plate. Get it TIG'ed up and should be getting somewhere.....

Cory

it's getting exciting now :evil: !!!!!!!!!

leon

Was it boring up until now!? Lol

Cory

NakedFun wrote: Was it boring up until now!? Lol

Cory

weeeeell,

i had seen that other stuff happen before :woohoo: .

leon

Ouch!! Good thing I am hedging my bet with the spoked rims..... Lol

Cory

mmmm spokes.

good thing you live in Minnesota,

or wireman would already be over there humpin your leg :woohoo: !


leon