V-Max Rear Gears

[lsutley]

I have a nice 92 V-Max pumpkin ready for installation in my 86 Royale. I have the original V-Max drive shaft and have been told that that must be substituted for the Venture shaft when the swap is made. The V-Max shaft is considerably shorter than the Venture and with the two units side by side I can not determine the necessity for the V-Max shaft to be used.

 

Is there anyone out there that has completed this exchange that can offer some assistance?

[Beau-Kat]

Just installed a Venture pumpkin in my '98 VMax to lower my RPMs about 500. I did not change the shaft. No problems going that way. I understand the VMax shaft is a little more beefy than the Venture's.

 

Why would you want to put a VMax rear end in a 1st gen? Since the VR and RSV transmission gearing is different, my '88 VR already turns more RPMs than my MMRSV at speed. I wouldn't see the need to raise the RPMs further.

 

Now, if you're making a cool dragster out of the Venture... then the beefier shaft may be needed with the VMax pumpkin.

 

Maybe I answered my own question with that one...swap out the pumpkin and hang on!

[skydoc_17]

Hey Lester,

The VMAX final drive swap is a dandy way to boost the get up and go in your First Gen.VR!

Check out this thread I started about the swap. ( The FJR1300 has the same gear ratio as the VMAX final drive)

 

http://www.venturerider.org/forum/showthread.php?t=37388

 

You will want to us your VR drive shaft as the VMAX shaft is too short. You will also need a shim on the drive shaft tube to keep the VMAX final drive perpendicular to the Drive shaft axis. I machine those shims, if you are interested, PM me. With the increased RPM's

of the VMAX Final Drive, two other areas you will need to keep an eye on are the Valve Cover Gaskets, If they have not been changed in the last few years, (or never!) you may find that they will start to weep oil. The second thing is your Air Box Vacuuming oil mist out of the Crankcase, if this happens, check out this link:

 

http://www.venturerider.org/classifieds/showproduct.php/product/2333/cat/500

 

Other than that, just remember to "Hold ON!" when you drop the hammer!

Earl

[Chaharly]

Just installed a Venture pumpkin in my '98 VMax to lower my RPMs about 500. I did not change the shaft. No problems going that way. I understand the VMax shaft is a little more beefy than the Venture's.

 

Why would you want to put a VMax rear end in a 1st gen? Since the VR and RSV transmission gearing is different, my '88 VR already turns more RPMs than my MMRSV at speed. I wouldn't see the need to raise the RPMs further.

 

Now, if you're making a cool dragster out of the Venture... then the beefier shaft may be needed with the VMax pumpkin.

 

Maybe I answered my own question with that one...swap out the pumpkin and hang on!

Is pumpkin crazy motorcycle talk for transmission?

[Beau-Kat]

Is pumpkin crazy motorcycle talk for transmission?

 

Not the transmission, but the rear end (ring and pinion set contained within the overall housing).

 

I usually prefer to say rear differential, but the thread was started with "pumpkin".

 

The term pumpkin was really probably derived from a Ford's rear differential which could be unbolted (from the front) of the rear housing and removed as a single unit.

 

I know I called my rear end ring and pinion unit a "pumpkin" (or in SC, a punkin) in my first vehicle, a 1966 F100 truck.

[Condor]

I have a V-Max final waiting in the wings for the '91. Not looking for more power, but looking for a little lower gearing while pulling a trailer with two up. I may be the only one thinking along this line, but for me it should work...

[Sheradan]

So how much does the Vmax rearend hurt fuel mileage?

[Venturous Randy]

I am looking at putting a V-max rearend in my 83 as part of putting in the 2nd gen transmission that I now have and am going to install. I think that will be just about a perfect setup for what I want.

RandyA

[skydoc_17]

Hey Jack,

I get 42 MPG in my 87'VR, (I have other mods, heads, cams, Carbs) For pulling a trailer, this mod is a "Must Have" item. You won't even know you have a trailer hooked up. I do a lot of 2up riding and it's the same thing, you don't even realize you have a passenger on board. "Bang for the Buck wise" this is the best mod you can do for the money. The only time I have ever gotten "bad" gas mileage was because the bike was winding up so good and I couldn't keep my fist out of the throttle! (temporary insanity) Once I cam to my senses again, the gas mileage went right back up again.

 

Earl

[Condor]

Hey Jack,

I get 42 MPG in my 87'VR, (I have other mods, heads, cams, Carbs) For pulling a trailer, this mod is a "Must Have" item..

 

Earl

 

 

That's what I'm thinkin' too Earl. This '91 has a lot of 'stuff' on it, but I never got to talk to the PO to find out if he'd done anything to the engine or suspension. I guess it's discovery as needed. Heck, it may already have a V-Max in it. I'll know for sure when I get it loaded up. I'm not sure about MPG, or if it'll act the same way as the '83 and get 38 on the flats and 50 in the twisties but the V-Max may help a bit??

[lsutley]

Thanks for the replies to my query. The reason for the gear change is that the bike is attached to a Motorvation Formula sidecar and a lower gear ratio should help with the overall performance and may even improve the milage.

 

The use of the VR driveshaft did seem to be the correct application but I was not sure and did not want to chance the distruction of the differential out in the middle of nowhere.