GPZ750R1 -82 Will it be yet an other green Kwack

scubaanders wrote: ....
In short, we have a used Gpz750R1 swing arm for sale that some think can be brought back to life with a little JB-weld.

Nah! Just some 3 minute epoxy and you're golden.

You forgot to use some whiskey. Would have come right out. Or was that bottle of scotch the last one you had.

Ohhh no James.

Scotch is only used for barter. :woohoo:

But we were considering dipping the hole frame in Seagram's Seven Crown and Coke (Popular add in Cycle and Cycle World back in the eighties). Coke for the phosphoric acid and together with Seagram's it tastes just as bad as the Acetone and transmission fluid cocktail. :pinch:

/A

I have my bike up in my buddy Erik’s garage (50km away) so there is a lot of things that need to work in order to get work done on the bike, and to make things worse Erik gave his daughter a Hoverboard for X-mas. Guess you can figure out the rest. . :blink: . . . yes there were some serious surgery :S needed to get him back in good working order again and the days we had set of around new years were lost.

Anyhow, we are back at it.

First up, fitting the Zephyr 750 swing arm.



The Gpz750R1 measures 230mm between the studs and the Zephyr 750 swing arm is 234mm, so while I shaved of 2mm on each side Erik milled the Zephyr pivot tube down to 230mm.



Secondly we had to deal with the fact that the swing bolt is 16mm and the id of the Zephyr pivot tube is 20mm. Our fix was to fit a piece of high precision steel tube that by chance had just that od/id inside the pivot tube.



And everything went on the bike like a charm.



In order to secure that the end seals stay in the swingarm, Erik made two spacers of delrin that fits over the studs in the frame and will stop the seals from getting out of the swingarm. (not in the picture)



Next up is fitting the wheels, which means changing the wheel bearings from 20mm id to 17mm to fit the Zephyr wheel axels and centering them in the frame.

Unfortunately we ran in to a little bit of a snag with the front wheel as it turned out that the donor bike, a ZXR400 has 210mm fork spacing and the Zephyr fork only 200mm which put the wheel ca 10mm of to the right. Bummer. :pinch:

/A

Nice to see you back at it.

I don't see anything that you can't tackle with the addition of a few more beers. If that doesn't work get a bigger hammer and switch to whiskey.

James according this diagram I found on the net, that is based on an independent studies done by GAOCBB Beer outperforms Whiskey at all times by its ability enhance the output of Elbow grease measured in part pers million, per kilo pound meter per second.



I believe this information is probably withheld from the general public by the authorities due to the lobbying by WAOFH.

Therefor we shy away from whiskey in the garage, unless it’s the Coke and Seagram’s Seven Crowns cocktail we use as a rust solvent.

/A

Next up was swapping the bearing in the rear wheel in order to accommodate the Zephyr’s 17mm wheel axle.



This means that we also had to make a new 17mm id collar to go inside the wheel.



The by the use of suitable Scandinavian whether we shrunk the bearings and the assembly was done without the use of brute force.






All the spacers needed were fabricated with 17mm id, in 6061 with the original as templates and then finally Erik mild out a holder for the cush drive so that we can mill the hub in order to line up the chain.



At this point we don’t know if an original front sprocket from a ZX750A1 that has an offset approx. 5mm will be sufficient or if we have to go the full mile and get our hands on a 3/8 25mm 13 spline GS1000 front sprocket.

We decided that we will not go any further with the ZXR400 front wheel that turned out to wide over the hub. :dry: I got my hands on a ZR-7 front wheel in Italy that hopefully will be a strait swap and that will allow us to keep the speedo gear. The wheel was cheap and it will be too much hassle to mill down the wheel as we don’t have access to a lathe large enough to accommodate a 17’ wheel.

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scubaanders wrote: James according this diagram I found on the net, that is based on an independent studies done by GAOCBB Beer outperforms Whiskey at all times by its ability enhance the output of Elbow grease measured in part pers million, per kilo pound meter per second.

I believe this information is probably withheld from the general public by the authorities due to the lobbying by WAOFH.

Therefor we shy away from whiskey in the garage, unless it’s the Coke and Seagram’s Seven Crowns cocktail we use as a rust solvent.

/A

But here in 'Merica being hard working non-conformists we usually break down the barriers of scientific gobledy-gook. Just as a bigger hammer is often contrary to conventional wisdom it is often just what's needed. We long ago shed the yoke of the foreigner's, funny talking, metric usin', tyrannical ways.

Seriously, it looks like you are having too much fun.

So the ZR-7 wheel showed up from Napels and its funny it looks the same as the ZXR400 wheel and you really have to look at bearing fittings to tell them apart.

The ZXR400 wheel didn’t want to center up with speedo drive in place, it ended up 10mm to the right.



Quick swap to the ZR-7 wheel it lines up beautifully.



Just need to fabricate a wheel axle spacer that is 25 mm as stated on the parts fish.



Then when we were looking at the original front fork we noticed that the brake joint with the lower fairing mount might just fit.



It did, as well as the instrument cluster and the ignition lock. Nice now we can focus our attention on lining up the chain, Now I need a 3/8 offset sprocket preferably 15-16 tooth and I would love a 520 but I guess I have to settle with a 530. It's a jungle out there and the size of the front sprocket Is limited by the clutch push rod so we will see what I can get my hands on.

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I thought I did a smart thing ordering my offset front sprocket from within Europe even though it’s a little bit more expensive. Shipping from the US can be pricey and within Europe they won’t slap you with import and VAT once over.

How wrong was I, unfortunately the guys I order it from had a manufacturing mishap and lining up the rear wheel and milling down the rear wheel hub is next. So we just had to wait . . . .

Finally the sprocket turned up this week so hopefully we will get going again.

But another buddy of mine has been hard at work painting up his own Honda Vf750F Spencer replica and had time to squeeze in some more parts in the boot, while waiting for paint to cure on his more elaborate paint scheme.







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Hi Scubaanders.

Have been reading your thread as I'm doing something similar and have had some of the same issues. My base is a 750 zephyr and I have a ZRX1200 swingarm in it now. We faced the same issue with the pivot bolt being seized so the zephyr arm had to be cut out. I'm now getting custom shocks made, but I'm not sure on the difference between the zephyr750 swingarm and the zrx1200 when it comes to the pivot to shock mount dimension. I can measure the new zrx one no problem but I have no way of measuring the old one as it's scrap!

Would really appreciate if you could do a measure of your zephyr 750 swingarm. Center of pivot to center of shock mount.

There would be a bottle of whisky in it for you if you ever came to Australia! Nothing less than 12y/o of course

Who am I to turn down such a tempting offer.
I have the green kwack at a buddy of mine, but I will send him out with a ruler and report back.
Unfortunatly the project has been moving slowly as I have spent all my time on my daily ride "New gold dream" aka the Ebola bike, as fluids has been poring from every possible opening and even the bare skin of that bike.
/A

baldy110 wrote: Wow great deal on a great bike. Here is my 82 GPz750R1, turned it into an ELR clone. Used the swingarm and shocks off a 1999 ZRX1100. Swapped a warmed up 82 GPz1100 engine into it also. The thing is an absolute blast to ride. Handles like the 750 but has over 100 HP, weighs 420 pounds and is wicked fast. If you got any ?? let me know.

Sooo, a KZ1100 engine fits in the GPz750 frame? I've heard it won't work, but I never tried for myself yet. What mods are required?