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Discussion Starter #1
Is that even possible
 

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Old Truck Junkie
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Go to the 800 vulcan. Those are chain driven.
It would be way too much work to do a change over. That is if it is even possible.
 

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Linkmeister Supreme
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Anything is possible given enough time and money.
Is it worth the trouble and expense? Not to me it isn`t.
If I wanted a chain or belt drive on my motor, that is what I would buy. JM $0.02 W
 

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Headbanger/Popes of Hell
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I do not like chain drive. not at all! at one time I had three bikes, 1 w/chain, 1 w/belt, 1 w/shaft drive. now I have 2 bikes. guess which one I sold? yup, the 1 with chain drive and I will never buy chain drive bike again. no thank you!
so why would you want to change the VN750 from shaft to chain?
 

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Shaft to Cahin

I seen this brought up before. I thought that the shaft was supposed to be an improvment. as far as I am conserned it is. Why would anyone want to go back to a chain? I use my bike on finished roads nothing wild maybe there is another side but I can't see it. I guess everyone has a right to believe what they want, but I will stick with the shaft.

Mcneuby :doh:
 

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There are several advantages to chain drives.... They weigh less, they transmit engine power more efficiently (shafts waste 5-8 hp) You can alter the overall gearing with a chain, and they don't "jack the rear" like a shaft can.

Modern dry film lubes make lubing a chain a painless and less messy operation. As do O ring sealed chains. Removing the rear wheel is easier, and yeah, they are cheaper to repair.

The only thing the shaft has going for it is it requires less maintenance. So, it's great for long distance bikes like touring bikes .... Or lazy owners...;)
 

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If only it had 6th gear..
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I don't mind shaft drive. It's quiet but performance wise, I'm a fan of chain drive. They don't require all that much attention with the newer lubes available. Only did it once a season on my GS and had no issues. I definitely would not consider the task if converting my V to a chain or belt. Not worth it. I would however, love to see what she'd do on the top end with the regained horsepower. As well as the ability play with ratios. My buddy's 750 Shadow is chain. Although my Vulcan out performs because it can rev higher before popping, his shadow just has a nice feel when yiu accelerate. Don't know how to describe it. More "there" maybe? Direct or whatever. I don't find that the Vulcan jacks as much as other shaft drives I've ridden but there's a definite difference in feel with driveshaft. Just throwing in my two cents for consideration. Peace.
 

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This is all quite informative! Love to learn new stuff on here :)
 

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Discussion Starter #9
the shaft limits customization alot... ie i cant get different rims, i cant extend swing arm, i cant change final drive ratio. I just wanted to see what ya'll had to say on the subject. thanks for every ones input. I am really starting to see a sport bike in my future. ZX-10R, GSXR-1, whatever it may be, it will be a liter or better. Im getting board with the lil 750
 

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Linkmeister Supreme
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There are several advantages to chain drives.... They weigh less, they transmit engine power more efficiently (shafts waste 5-8 hp)
KM, is that 5-8 hp relatively constant for a wide range of engine displacement/power rating? Say for the vn750 up to a 1600 cc engine.

I don`t know if it is true, but I have heard numbers as high as a 30% drop in HP for a shaft drive bike over a chain.
I think the vn750 is rated at 65hp, so a 30% loss at the wheel would be almost 20hp. :wow:

What do you think about the 30% loss of power claim?
 

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I was once a major fan of shaft drive. But now I'm not so sure. With 0-ring chains that don't require adjustment hardly ever, and new "clean" chain lubes that do not get thrown all over the bike, I would say that modern chains do not require any more maintenance than a shaft, at least most shafts. Chains do require maintenance more often, but usually only a few minutes at the time. On most shaft drive bikes, you have to remove the whole rear end every 10,000 miles or so, and lube the splines on the engine output shaft, the U joint, the rear of the driveshaft, and the final drive gearcase, on both sides, where the driveshaft goes, and where the wheel goes. I thought that all this was specific to the Vulcan 750, but it isn't. I now know of at least five different bikes that require this, or they will chew up their splines. Any BMW, any Honda Goldwing, any Vulcan 750, any Yamaha V-Star, and any Suzuki Intruder.

Shaft drives on bikes are not trouble and maintenance free like they are on cars, though I don't know why they can't be. On my Vulcan 750 and Goldwing 1200, I go through this 2-3 hour procedure twice for each rear tire I wear out. The Goldwing has some room under the front boot to get to things, but the Vulcan is a pretty tight fit, and very frustrating. So, I'd say the maintenance time is actually about the same.

One problem a chain drive does not have is super expensive parts. The final drive on a Vulcan 750 costs $1000. That's a lot compared to a chain and sprockets. Add in the driveshaft, final driven shaft, and the rear wheel (at least on the Goldwing, they eat rear wheels and final drives if you don't lube the splines where they engage the final drive, and do it often)

I have not had to adjust the belt on my '97 Road King since I got it, other than when I replaced the rear tire.

I think my love affair with shaft drives on motorcycles is about over. I have had the rear end apart on my VN760 6-7 times since I bought it new. I would definitely prefer a chain if bikes still had centerstands.
 

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If only it had 6th gear..
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KM, is that 5-8 hp relatively constant for a wide range of engine displacement/power rating? Say for the vn750 up to a 1600 cc engine.

I don`t know if it is true, but I have heard numbers as high as a 30% drop in HP for a shaft drive bike over a chain.
I think the vn750 is rated at 65hp, so a 30% loss at the wheel would be almost 20hp. :wow:

What do you think about the 30% loss of power claim?
I'm curious too. Some horsepower ratiings mention "at the rear wheel". It certainly would be a bummer to find that the 65 hp is whittled away by the shaft's inefficient transfer of power and thus not realistic :(. I can't imagine it being as much as 30% with our bikes though since they'll keep up with bigger bikes and even out perform some :confused:

Side note: Has anybody figured the horsepower gain from ear shaves, degoating etc? Just thought of that now but I'll go check the forums.
 

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HP can be measured at the engine or at the rear wheel. It will always be higher at the engine, because no drive system is 100% efficient. It is usually accepted that a chain is considerably more efficient than a shaft, but just how much depends on a lot of things. Sportbikes have always been chain driven, so have dirt bikes. A chain is a lot lighter and less complicated than a shaft, especially on bikes like the VN750, which has the front bevel drive gearcase to rob even more power. The Goldwing's is more efficient, because the crankshaft runs front to the back, and the output shaft comes straight out the back of the engine, without having to make a 90 degree change in direction like the Vulcan.

As for earshaves, degoating, aftermarket pipes, it is my opinion that not only do you not gain any power by doing these things, you actually lose some. What you gain is noise.
 

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10,000 mile spline lubes can be a dealer job. If you have a chain, you have to actually take care of the thing yourself...

Job Security!

Shafts also do better against the weather, but sometimes I wonder where Kawa went with this bike, besides everywhere. Single crankpin, shaft drive, liquid cooled, and that goat's belly. It certainly is a bit of an odd duck, like they took a little bit from everyone.
 

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Being an auto mechanic, I have never gone to a dealer, or any other shop to have anything done to a bike. To me, being a motorcycle enthusiast means doing your own service because you want to, because you enjoy it. Plus I would never trust a shop to do something like that right. Motorcycles are not cars. I'm just guessing here, but I would say that 90+% of motorcyclists are actual enthusiasts, while maybe 5% of car drivers are (yes, I am one of that 5%)


As for the Vulcan 750, it has got to be the weirdest motorcycle I have ever seen. It has 2 carbs, 4 cams, 4 cam chains, 4 spark plugs, liquid cooling, an oversquare bore and stroke, 10.3:1 compression, all things you would expect to find on a performance engine.

But then they used a 55 degree single crankpin design, rubber mounts, and a power robbing counterbalancer to smooth it out, instead of using offset crankpins to obtain perfect primary balance. They used hydraulic valves instead of solid lifters. (this may have been a redesign, because you can't get the covers off with the engine mounted in the Vulcan frame) Then they used a power robbing shaft drive, with 90 degree angles on BOTH ends of the driveshaft. Any time you change the direction of power flow, you lose power. That front bevel drive gearcase sure looks like an afterthought to me. Then they put a highly restrictive intake and exhaust system on it. Despite it's dual carbs, it has no real airbox. That "surge tank" has such a small volume it might as well not even be there. I personally believe the "goats belly" adds power, it serves as both an expansion chamber and crossover, to relieve backpressure from the uneven firing pulses of the single crankpin v-twin. From what I can tell, both the mufflers and the "ears" are a lot more restrictive than the "goats belly", and removing it does not increase power, it only makes more noise.

The Vulcan 750s conflicting design issues seem to indicate it may have gone through several redesigns before being installed in the Vulcan. Then there is the way it looks. While the other 3 Japanese cruiser engines had fins, and were at least designed to LOOK air cooled (and the Virago actually was), no attempt was made to hide the fact that the Vulcan 750 is liquid cooled. They didn't even bother to put fake fins on it. One magazine editor said it looked like a water pump. It definitely appears to be a frankenstein engine, rather one that was designed all at once. It looks like Kawasaki went to great lengths to adapt this engine to fit the Vulcan. I'd sure like to know what actually happened.
 

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If only it had 6th gear..
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As for earshaves, degoating, aftermarket pipes, it is my opinion that not only do you not gain any power by doing these things, you actually lose some. What you gain is noise.
Thanks for the info and I appreciate and respect your knowledge. I have to disagree with the statement about losing power by the ear shave. It simply isn't true when done correctly. I can tell you honestly that my bike performs much better with unrestricted air intake and larger jets. This is just logical and they use even bigger jets for racing. My front wheel almost hydroplanes at WOT from standstill and it didn't do that before. I haven't done any major mods otherwise and except for the pickup tolerance mod, I don't plan to change anything regarding my exhaust or degoating (I think the belly is there for exhaust balance and back pressure and I do agree it seems plausible that you could lose some performance by removing it). That said, you certainly know quite a bit about engines, performance and mechanics in general so thanks for sharing your knowledge. I also agree that the VN is a weird egg, :). I like it a lot but yeah, it's strange that they put all that technology into an engine and didn't go with belt or chain to use it's full potential AND, as I've said before, capped it's top end with only a 5 speed tranny:mad:.
 

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Old Truck Junkie
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They did all that to make as maintence free as possible for the general riders. And also it has very good mpg to the power that is delivers.
 

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If only it had 6th gear..
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I may be wrong, just going from memory here (a dangerous thing) but I thought I read somewhere that this engine was initially used in a Kawi sportsbike and then modded/adapted to fit the vn?.? Tried to find something on it but no-go. But you're right, there does seem to be a bit of "hmm, that won't work, let's change it to this" that went on. I think what niterider said is true also. They wanted the 750 to be rider friendly and low maintenance. Woulda' been nice if the accts worked for a good part of the bikes life, and if the splines were lubed initially.
 

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It would seem unlikely that Kawasaki would build a v-twin sportbike back in those days. That initial engine design was probably started in the early '80s. To my knowledge, no Japanese companies have ever built v-twin sportbikes except Honda (VTR1000, RC51) and Suzuki (TL1000) and they were basically Ducati copies, using a 90 degree V (or L as it could also correctly be called) twin. The single crankpin 55 degree layout must have been part of the original design, and wouldn't make sense for a sportbike
 
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