Venture Differential Review & Thoughts

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Based on my roll-ons with stock Maxes, the top speed MAY be better but you will lose all roll-ons (in the same gear) as you always start at a lower rpm. You may not even be faster as the aerodynamics and HP of the stock Max may not allow you to reach redline in top gear.
 
Top speed will be less unless you have a lot more HP to pull the new gear.
 
You made an overlooked and excellent point as to what rear wheel you have. I have a 190/50-17 Lightcon with a Shinko drag radial "Hook Up" on my 1500. My oem shaft drive is much more Explosive than my Venture.

rick rash
 
I had the Venture diff on my bike for 2000 miles, really didn't like the performance. The bike just didn't windup as fast as with the stock diff. I was also running a 190/50/17 tire, so when I went back to stock the bike pulled much better. Granted I was running around at a higher RPM all the time, but with flat slides the bike ran better with the stock diff and short tire.

If you want a highway cruiser maybe you should by a Venture. . .

IMHO
 
so I'm thinking about putting a venture rear drive on my 85 v-max, I have the drive shaft and drive, if I can find a stud to put in the hole so the shock will fit, what did you do to make this work,?? did you take the shaft out of the swing arm and use the the ventures.?? let me know of any thing you can think of or any photo's would be great,
 
I have recently been thinking about this modification also and have a question. My ride to and from work is about 15 miles of 70+ mph on a local interstate. Now at 70 my tach reads 5000 rpm which I believe has to suck gas. Is it better to go to the Venture diff or does Sean still do an OD? And will either significantly lower my RPM's with a stock rear tire set up?
 
Yup I totally agree with that. The motor just hasn't got enough pull to get redlining in 5th with the venture drive, but it does with the OEM drive.

Yep...mine runs out of steam at around 88-8900 in fifth, which is 140-145. I haven't found a downhill stretch suitable for those sort of speeds, that's on flat ground. I suspect with the usual full system/carb kit to get it up past 120hp it would eek out another few mph, especially if you tuned it for top end.

But my motor is stock, and with the stability of this bike, I'm not sure I'd really want to push it much faster than 140 anyway.

HOWEVER, even stock motor/venture drive, the top end is officially faster than a M109 with the stock speed limiter disabled(that neuters the engine past a certain RPM in fifth gear only). We wound it out the other day and I got up to ~145 indicated and walked by him....as I went by I saw the "tach bar" on his handlebars was completely filled with the last one flickering....so it was at the actual RPM limiter in fifth. w00t! He claimed after that his speedometer was pegged at the end of the scale well past the 150 mark. I'm sure it was, and I'm also sure that the M109 is equipped with a dream-o-meter. I've GPSed my speedo and it's real close....80 indicated is like 79 actual. So 145 indicated, maybe 140 actual.

My Magna would indicate 80 and actual was like 72..... 100 indicated was actually 90.
 
You use the Vmax shaft not the Venture. You can either buy a new stud or move your old vmax stud over (sometimes a challenge to get out).

It will be a 10% change with the diff swap. So 10% from whatever current rpm you are measuring from. Our OD trans is more like 23%.

This last trip to Eureka Springs saw a best of 49mpg out of one bike we have the OD in. That's with his saddle bags and gear.

Sean
 
I have recently been thinking about this modification also and have a question. My ride to and from work is about 15 miles of 70+ mph on a local interstate. Now at 70 my tach reads 5000 rpm which I believe has to suck gas. Is it better to go to the Venture diff or does Sean still do an OD? And will either significantly lower my RPM's with a stock rear tire set up?
I have pretty much the same distance to work (16 miles) as you and I absolutely love my venture diff. At 70 mph I'm at 4500 RPM, the bikes seems to have less vibration compared to OEM which makes for a more enojoyable ride. In city driving I found that the 1st gear became more usable. With the OEM diff the 1st gear felt very "short" it seemed that I had to shift into second in no time, with the venture diff I can acually stay in first longer to build up speed which IMO makes it more usable. From light to light, I honestly do not notice a difference in performance, vmax has plenty of torgue to get you moving, fast, even with the venture diff.

I do most of my riding at 50+ mph so for me it works out perfect and I would not change back. When I do go into the city I keep it in lower gear. For example instead of being in 4th gear at 3K RPM I would keep in in 3rd at 4K RPM.

That is with stock wheels and stock rear tire.
 
It sounds (reads) like if my riding is gonna be either/or city/long haul I should go with an OD gear and not a venture diff... That way I get the around town punchiness and the on-road mpg advantages with the same final drive. I'm assuming that a venture final and an OD 5th would be a silly idea for me since I don't usually cruise at 80mph+.

OH, and first post. Great resource here.
 
Just an FYI. I have a gloss black Overdrive Pumpkin ( A Morley version I think) for sale in the buy & sell section. Trying to pull the trigger on a Gen II. Great winter mod and pics available if you send me an email address.Thanks and back to your regularly scheduled programming....
 
It sounds (reads) like if my riding is gonna be either/or city/long haul I should go with an OD gear and not a venture diff... That way I get the around town punchiness and the on-road mpg advantages with the same final drive. I'm assuming that a venture final and an OD 5th would be a silly idea for me since I don't usually cruise at 80mph+.

OH, and first post. Great resource here.



Greetings Dave! :biglaugh:
 
I have recently been thinking about this modification also and have a question. My ride to and from work is about 15 miles of 70+ mph on a local interstate. Now at 70 my tach reads 5000 rpm which I believe has to suck gas. Is it better to go to the Venture diff or does Sean still do an OD? And will either significantly lower my RPM's with a stock rear tire set up?

Sean's OD is obviously the best way to go by a long shot - you keep the OEM ratios in 4 gears, and get a true overdrive for highway cruising (it's actually the Venture top gear ratio).

BUT, you can get a Venture pumpkin for a few hundred $ or less, whereas doing the OD 5th requires dropping the motor and splitting the case, which is very unfortunately rather more $$ :confused2:

I ran a Venture pumpkin on my '86 pretty much the whole time I had it and I liked it, a lot. I did have a 90-mile I4 commute between Trampa and Orlando, though! I don't think it made hardly any difference at all in fuel consumption, but it did give me a much better cruising speed for the same revs.

Also, I liked the taller gears, when the Vboost hit in 2nd or 3rd it really felt like flying!! But, I couldn't get it past 135mph with me (190lbs) and a tall windscreen.
 
Sean's OD is obviously the best way to go by a long shot - you keep the OEM ratios in 4 gears, and get a true overdrive for highway cruising (it's actually the Venture top gear ratio).

BUT, you can get a Venture pumpkin for a few hundred $ or less, whereas doing the OD 5th requires dropping the motor and splitting the case, which is very unfortunately rather more $$ :confused2:

I ran a Venture pumpkin on my '86 pretty much the whole time I had it and I liked it, a lot. I did have a 90-mile I4 commute between Trampa and Orlando, though! I don't think it made hardly any difference at all in fuel consumption, but it did give me a much better cruising speed for the same revs.

Also, I liked the taller gears, when the Vboost hit in 2nd or 3rd it really felt like flying!! But, I couldn't get it past 135mph with me (190lbs) and a tall windscreen.

I love it g! Most guys would say lower rpms for a specific speed, but u took full advantage!
 
You use the Vmax shaft not the Venture. You can either buy a new stud or move your old vmax stud over (sometimes a challenge to get out).

It will be a 10% change with the diff swap. So 10% from whatever current rpm you are measuring from. Our OD trans is more like 23%.

This last trip to Eureka Springs saw a best of 49mpg out of one bike we have the OD in. That's with his saddle bags and gear.

Sean

Hey, Sean, your OD pumpkin must raise ALL the gears by 10%, so how does it compare with stock in the first 2 gears for acceleration? I would imagine it still outpulls most other bikes. Also, does your OD trans use all stock gear ratios except for 5th? I'm still trying to figure out what I want do with mine.
 
The diff does affect all the gears. It's slower acceleration and less wheelies (one fun measure I use when test riding a bike lol). It was .3 tenths at the track which is quite a big distance. Most won't have a problem with the loss since it's still going to pull well.

The 5th gear od is a bigger rpm reduction and only for that gear (all others are stock). I like this because I can still play but have a bigger reduction for cruising!

We can mix and match ratios around somewhat but there aren't an unlimited amount of options. I do have a star trans that has longer gearing in the lower gears and a 15% reduction for 5th. So a little more then the diff but not as much as the Rstar 5th. This combo should work quite well for a big power engine.

Sean
 
The star trans is not a "bolt' in. We have to do modifications to the dogs for them to engage properly. Once done though it's a great mod.

Sean
 

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