My GPz750 Resto-mod (pic heavy)

i'm with puffin.
the shock is not symmetrical so there for your mount isn't going to be symmetrical.
the shock decided for you :lol: !

leon

I really haven't felt like dealing with notching the rest of the tubes at compound angles so I've been gathering and fitting parts over the last few weeks.

I got a '98 Vfr800 front rim, a set of Zrx1100 forks and a set of Zx11 triples with handlebars to start.

First thing was to buy some 25mm ID bearings for the Vfr rim to go from the 20mm stock axle to the 25mm Zx11 axle. But then I realized that the 20mm ID inner tube bearing spacer would be impossible to use so I took a chance and ordered a used Zx7 spacer hoping that it would be too long and I could trim it to size. It was so that was easy enough to shorten in the lathe.


Then I found out the Vfr inner hub has some extra casting material that needed to be filed down to let the bigger OD of the spacer tube pass through.



So with the correct bearings, everything played well together until I had to figure out the wheel spacers. Because the Zx/Zrx11 uses a mechanical speedo drive the left axle clamp is offset to get the needed room. This meant that I could not simply make two identical spacers. But here's what I came up with...the left spacer being about 4mm longer than the right.





Everything together and ready for me to figure out brake fitment and spacing


Which lead me to my next headache: finding a set of 310mm rotors that have the correct offset and bolt pattern for a Vfr800 rim in a set of Zrx1100 forks held in place by Zx11 triple clamps. I've looked and they don't exist. So I did a lot of research and found that I could possible use a set of Cbr600RR rotors or certain models of Gsxr rotors with the right adapter/spacer. I found a set of used aftermarket Cbr600RR rotors for a good price and bought them just so I'd have a starting point.


I also bought some 5" OD x 1.00" thick 6061 round bar stock from eBay.


All was right with the world as I had drawn up some sketches of the spacer/adapter until I placed the rotor on the wheel to see what actual offset I needed.


It turns out that I failed to take into account a small lip to hold the rotor concentric to the space. So now I'm pretty sure that the fastener that will hold the spacer to the rim will also try to take up the same space as the concentric lip. And that's where it's been sitting for the last week or so.

Any thoughts besides buying more aluminum and different rotors?

Later, Doug

maybe i'm missing something :whistle: .



but it looks to me like you could countersink the bolts the hold the adapter to the wheel and then machine your locating lip around.
the countersinks will interrupt with the lip but you will still have enough lip to locate the rotors.

what am i missing?

leon

531blackbanshee wrote: but it looks to me like you could countersink the bolts the hold the adapter to the wheel and then machine your locating lip around.

Hmmm.. It hadn't crossed my mind to drill the holes first. I just assumed that machining the offset/lip and everything else would be first. I'll have to take another look at my process.

Thanks Leon!

Later, Doug

hows the Brainstorming going Doug have you a solution ?

Not a solid one yet. I wouldn't have an issue if I had a vertical mill but I don't so I may go with Leon's advice, I'm gonna try to get out to the garage this weekend as it'll be in the upper 40's compared to the mid-20's/low 30's recently.

Later, Doug

Good stuff, man. Drive on.

I forged ahead today on the brake rotor adapters/spacers. Let me just say that working with 5" OD stock on a 7" swing lathe takes some out of the box thinking but I think I got most of the problems solved except the spacer-to-rim mounting bolts being so close to the lip. Using socket headed bolts and thinning the lip a small amount will hopefully completely solve the issue.

First I drilled a hole in the center and used an expanding arbor to hold the workpiece so I could form the lip that keeps the rotor concentric. Once that was done I drilled and tapped two holes and used those to mount the piece to a faceplate where I could bore the ID to fit over the rim's hub.




Then with some careful positioning I used a transfer punch to mark two of the holes for the spacer-to-rim bolts.



I still need to finalize the thickness, drill the other 8 holes, plus clean it up a little to reduce some weight, but here it is in a temporary state.


At least I made progress, as I've been brainstorming about this for a week or so now.

Later, Doug

I finalized one side today. I was able thin the lip and get enough clearance to use socket headed screws just fine. The spacer/adapter actually ended up thinner than I thought but still plenty of material for strength.





How it looks all bolted up.


Just about as centered as I think I can get it.


Later, Doug

Nice work !!

Since the holiday is done and life is back to normal, I made my way back to the garage and made the third version of the right lower shock mount tube.



But I'm not sure if I want to keep a similar design for the upper tubes or go parallel with them..



Later, Doug

Soooo........the Vfr800 rim I bought turns out to be a 16" Cbr900RR front rim. I didn't notice it until I went to mount the 17" mock-up tire I have and the tire practically fell over the 16" rim. So now I'm back to looking for a 17" Vfr rim plus trying to resell the 900RR rim since it's been more than 2 weeks and the seller won't take a return.

I'm hoping that when I do get a proper 17" rim my axle spacers and brake adapters will still work but I doubt it.

Later, Doug