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Belting it out
Belt drive systems on bikes have a long history; Harley-Davidson has been using them for a long, long time. Some of the truly big-inch bikes use belt drives! There are definite advantages to a belt drive vs a chain drive; not the least of which is the cool factor...
For the Vulcan 800, which comes from Kawasaki with a chain drive, a company called Scootworks produces a belt drive kit called the Wide Drive Belt Drive Conversion Kit. It's a reasonably easy retrofit to do, with nothing different than changing that sprockets and chain on the OEM system. Let's have a look at the pros and cons:
Pros:
Cool factor; especially with the chrome rear pulley on the Wide Drive system!
Power transfer; chain drives rob between 5% and 15% of the power available at the output shaft (countershaft) from the rear wheel. This is due to factors such as chain stretch that are inherent to roller chains. In contrast, shaft drives rob up to 20% (depending on design) due to the number of moving parts and changing directions of power application. A belt drive has virtually zero stretch once it's been run in, is always under tension (as opposed to the chain, which must maintain a certain degree of freeplay), and is a more efficient power transfer medium; there is less than a 5% power loss with a belt.
Noise; chains sing. Belts don't. There is frequently a certain speed at which belts will make a noise (varies with the width/thickness/design of the belt; on the Wide Drive system, it's approximately 20 MPH) due to the belt reaching its resonant frequency, but before and after that, it's virtually silent.
Maintenance; chains require cleaning and slack adjustment periodically. Belts don't. As mentioned above, once the belt is run in, they basically don't stretch. They don't need to be cleaned and they sure don't need to be lubricated.
Longevity; chains and sprockets wear out, and need periodic replacement. They wear together, so when the chain needs replacement, it's a good bet that the sprockets do also. A top-quality X-ring chain can cost as much as $260.00! 20,000 miles is considered excellent longevity for a chain and sprocket set; but this presumes good periodic maintenance. Belts wear out eventually, but at 20,000 miles the belt on my 800A was in excellent shape (more on that later). A top-quality replacement belt runs just over $100.00 from Scootworks. However, the belt doesn't wear the pulleys the way a chain wears the sprockets! Metal-to-metal wear on the chain and sprockets is the cause; and a belt isn't metal. There's a damn good chance that the pulleys that get installed when doing the conversion will still be on the bike when it dies of old age and high mileage... providing a nemesis of belt drives doesn't occur; rocks. Getting a rock stuck between the belt and the pulley can put a hole in the belt (bad; this necessitates replacement ASAP) and can chip/score the teeth on the pulley, which will cause undue wear on the belt later.
Safety; if a chain breaks (they do; not very often, but they do), it can wrap around moving parts and lock up the rear wheel. If a belt breaks, it just falls off (don't ask how I know
Cons:
Expense; the initial outlay to install a Wide Drive Belt Drive Conversion Kit is over $600.00. Of course, as mentioned above, this could be factored in as eliminating the need to replace sprockets and chains periodically; figuring a good set of sprockets and chain at $175.00, and needing to change every 20,000 miles, at the third change (60,000 miles) that's $525.00. The next change will run the total to $700.00. At this point the belt is still going...
Replacement; a chain with a master link can be replaced on the side of the road. A belt? Forget about it... the swingarm has to come off. Most any bike shop will have a 530 pitch 112-114 link chain (or be able to cut the length needed from a bulk roll) O-ring chain; it may not be the brand you prefer, but it will definitely get you home. A belt? Forget about it... the Wide Drive system uses a 30mm wide 8mm pitch belt, and the sole source of replacements is Scootworks. Even carrying a spare in the saddlebag doesn't help if the belt lets go on the side of the road...
Failure; there have been rare, but documented, cases of a front sprocket spinning on the output shaft. There have been, unfortunately, far more documented cases of this happening with the front pulley of the Wide Drive system. I'm one of those cases. In my case, only the pulley center spun, leaving the output shaft relatively undamaged. In many other cases, the output shaft itself was ruined, necessitating replacement; and at a shop, that runs about $1200.00. Not to mention the downtime...
This page will be expanded at a future date to include the failure to my bike, as well as others, along with technical explanations as to the probable cause of the failures, what could be done to make it better and more reliable, and what 800 owners who have already converted to the Wide Drive system can do to stave off potential failure down the road. Stay tuned...
For now, I'm sorry to say that I cannot any longer recommend that Vulcan 800 owners convert their bikes to belt drives using the Scootworks Wide Drive system.
 
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