Pre-E5 V7 Rear Spoked Wheel on V9

[Dirk_S]

TL;DR—It ain’t happenin’.

Pics below for illustration purposes.

I REALLY wanted to make this work. How lovely would it be to have a spoked 17” or 18” rear wheel on the V9, or even just normal, non-balloon’y wheels with only a few simple modifications that someone with even a slight interest in mechanical fondling can taken on themselves? After all, the pre-Euro 5 final drive of the V7 and V9 have the same style hub plate with 6 dogs fitting into the hub. Clearly we’re just mere steps from making this work, right?

Two issues stand out— (1) different size axles, and (2) discerning possible clearances/gaps that might occur. The first part could be a simple solution—find the proper bearings and see about using the V9’s internal wheel spacer inside the V7 hub. The second bit would require some Dremel work, but felt otherwise quite promising.

The final drive’s dogs indeed fit into the V7’s spoked hub like the V7’s own. The V9’s final drive, however, has an outer lip that projects across to the hub to close up the gap. This lip actually matches up pretty well to the V7 hub, but would need to be trimmed back with a Dremel without compromising structural rigidity of the pumpkin. I was pretty excited to think this was the answer, until I studied the V9 final drive further.

I realized all the thought and effort—including purchasing a V9 swing arm and final drive for the modification—were for naught because of this $@*%#€&~^ final drive vent poking INTO the hub. The inside of the V7’s hub lip clears the vent cap, LEADING ME TO BELIEVE THAT A V7 CAST WHEEL COULD STILL FIT A V9 FINAL DRIVE WITH THE AFOREMENTIONED MODIFICATIONS, but the V7 spoked hub’s inside spoke bosses (correct me if I’m using incorrect terminology) don’t clear this vent cap. This keeps my V9 Monza wheel mod potential alive should I choose to try a V7 cast wheel, but any hopes of using the V9 swingarm with the beefier double u-joint on my custom V7 enduro is tossed out. C’est la vie.

[Huzo]

Can you remove the vent, blank it off and re position one somewhere else ?
It’s only a vent to equalise pressure.

[Dirk_S]

Can you remove the vent, blank it off and re position one somewhere else ?
It’s only a vent to equalise pressure.

Appreciate the suggestion. I do believe a hex head, low-profile socket cap, maybe even a normal socket cap bolt should clear the spoke bosses. I hadn’t considered retapping a new vent, probably near where the previous small block vent always sat. I’d be curious about the structural integrity of a vent bolt threading into the aluminum with no casting built around it. I assume there wouldn’t be many threads to work with.

[Vagrant]

I bet they never changed the casting.

[Dirk_S]

I bet they never changed the casting.

That’s an understandable assumption given the small block’s slow evolutionary history, but Guzzi changed the swing arm, drive shaft, and final drive beginning with the early V9. There’s probably more new than there is shared. The splines are different, the mating end of the swingarm-to-final drive is beefier, the vent is shifted inward (free dog drive lubrication!). I believe the V9 final drive casting is the same as the E5 V7 and V9, but all fairly different from the final drives found on the V7 III and earlier small blocks. The V9 and V85 even look to have the same casting outside of the extra support for the V85TT’s mono shock. Pics for reference, all from the internet, including one poor soul whose final drive had a case of the runs.