Date: Tue, 2 Nov 1999 07:53:24 -0800 (PST) From: Kelly Cash To: maxout1200@yahoo.com Cc: vmax@mylist.net, V-Max@sayegh.org Subject: Re: V-max/venture rear end swap Message-ID: <199911021553.HAA12701@mailhub.Cadence.COM> > Heard that you have done this. I have 89 venture > and 85 V-Max Rear on the Venture doesen't appear > to be treaded for the V-Max shock stud. Do I have > to tap it for the stud? Also appreciate any > comments you may have on how this swap affected > V-Max performance? I swapped my pumpkins between my '87 Venture Royale and '94 Vmax. The Venture rear had the shock stud mounting hole already tapped. But it's tapped fairly deep inside. Use a flashlight and look inside. It may take a stud puller to remove the stud from the Vmax rear. (or you could just get another one) But I swapped 'em back- I found it only took performance away from both bikes. The Vmax was slower off the line, and the Venture has enough torque to pull it with higher gears. With the 'Max rear, the Venture had an almost imperceptible power boost on roll-ons, but the mileage was worse by 4.5 mpg. The Vmax didn't get the mileage gain I'd hoped. Less than 1 mpg better overall. The Venture's top end was reduced, and it felt like it was revving too high at speed. It was kind of like the Vmax had taken away first gear and added a sixth, and the Venture had thrown away fifth gear for a granny low gear. Also, the Vmax with the Venture rear had a strange rhythmic vibration which could be felt at 35-45 mph. Kind of a "bzzt. . . bzzt. . . bzzt. . ." Not tires, it went away as soon as I swapped the rears back. I suspect that the different length of driveshaft may have caused it. Maybe the Vmax shaft sits inside the rear an extra thousandth or three. It was most disconcerting- I rode that way 5000 miles on my summer trip. All the way I was worried something was going to come apart. Fortunately, it seems to have had no long-term effect. I've heard that to change the rears between a Vmax and Royal Star requires some machining somewhere. Wouldn't surprise me. I think the same reason why that's necessary is present in the Venture/Vmax swap, just not as pronounced. -K Also, I have the following recollections: It's a very easy swap, but do find out about driveshaft lengths. I recall there's a difference in length between the Vmax and Venture swingarms or pumpkins, I can't remember which. This means the driveshafts are different lengths- About 1/8" different. And it makes a difference. you do NOT want to use the wrong length. It can cause problems. If the driveshaft is too long, it'll put too much stress on the U-joints, rear end bearings, and probably the output shaft bearings too. If the driveshaft is too short, the splines won't engage fully, which may or may not be a problem with stripping. Not something I'd want to risk. If the swingarms are different lengths, you'll need to use the Vmax driveshaft. If the pumpkins are different lengths, you'll need to use the Venture driveshaft. What I found on my swap: The gas mileage increased about 1 mpg. Woo hoo. Hardly worth the effort, and there was a definite loss of "snap" in the acceleration. My Venture got a trivial amount of increased snap, but its mileage (and thus, range) decreased. I also heard a slight noise in the drive line somewhere on the Vmax after the swap. Like something was slightly touching in the shaft housing of the swingarm. I swapped the rear ends back, the ticking went away, and everything went back to normal. An interesting exercise, but I found it wasn't worth it. Your mileage may vary. Good luck, -K --------------------- Date: Tue, 2 Nov 1999 14:58:38 -0700 From: "TC" To: Subject: Re: V-max/venture rear end swap Message-ID: <005101bf257d$6c364960$1e00a8c0@tcamp.net> Kelly, On the Royal rear ... the shock boss is part of the casting but it is not drilled/tapped at all ... it is solid. You are also going to end up with a hole where the speedometer pickup is usually installed which will need to be plugged. Going the other way .... VMAX to Royal .. you have to drill a hole for the speedometer pickup and retainer screw .. I have noticed a lot of people have just been paying labor to move the ring an pinion from the VMAX rear into the Royal housing, (from what I have heard they are paying 6-8 hours average shop time for this assembly and setup). The pinion has to come out anyhow to drill the sensor hole ... so your half way there already .... campbell