Now that I've had nearly a year to calm down
In my humble opinion Scootworks belt drive is an under engineered piece of shit! I was leery of installing their system and should have listened to my instincts. This was the "wide drive" version of their belt conversion system.
My initial experience with the unprofessional nature of Scootworks had made up my mind that I would not be getting their belt conversion kit. Scootworks had essentially stolen the front pulley from my EN500A. At Scootworks request, I had sent it to them so they could borrow it for a "few days" to take measurements and prototype a new pulley. After about two months of hassling them to return it I gave up and bought a new one. One of the forum members had bought the Scootworks kit but ended up selling the bike before getting it installed. I happened to have some extra cash on hand and we worked out a deal for me to take it off his hands.
Being a mechanical engineer I was skeptical based on what little info I could get from the website and pictures. From what I could tell it appeared to be the same belt type that I worked with on industrial equipment. The application on the equipment had significantly lower load that what would be in a Vulcan 500 final drive. The loads on this equipment were within the capability of the belt but there wasn't a wide margin for additional load capability in the design. When the kit arrived my skepticism that it wouldn't work increased. The kit used a 1760mm long 30mm wide 8mm tooth pitch HTD belt system. Exactly the same belt type and width I had experience with on industrial equipment! There is a complicated formula for calculating the deflection at the proper belt tension of these belts. However for spans of a few feet or less you can simplify it to 1/64" deflection per inch of span with 10 pounds of force applied. I didn't measure the span between the pulleys on the bike but Scootworks spec of 3/16" with 10 pounds of force seemed to be in the ballpark but maybe a little on the tight side. Unfortunately even with the belt this tight anything over about 66-75% of full power would result in the belt ratcheting. I was extremely displeased to discover this but figured I'd see if I could live with it. It took at least 500 miles of trial and error to get the back wheel aligned perfectly so the belt wasn't riding to one side or the other of rear pulley. Again this further lowering my confidence in this system.
I knew I was going to take a 380 mile (one way) road trip down to West Virgina in the near future. I wanted to get 1,000 miles on the belt system to prove it would get me down there and back. I was only able to get about 600 miles in before the trip. I figured that was enough miles to prove it worked.
So my journey and troubles begin. About 100 miles into the trip I rearended a car in front of me. I won't name those involved (for my health and well being) but, a family member in the car was throwing a temper tantrum because their seat belt wouldn't release and was choking them. As a result of this the driver slammed on the brakes while pulling out of the parking lot. I bumped them at about 5mph or less. No damage but just enough to put a tire mark on the bumper and get my adrenaline going. I had only moved forward about 10 feet from a stop. 270 miles later a little south of Charleston the road narrows with a rock wall to my left and a several hundred foot drop to my right with no shoulders. There are also lots of twisties with steep elevation changes. Being a flatlander I was being extra cautious and not pushing it. The SUV crawling up my tailpipe did not make me any more comfortable. It was about two thirds of the way thru this narrow section of the journey that the belt started shedding teeth. Stopping was NOT an option on this section of road. I just kept going as smoothly as I could and relying on hopes and prayers that the belt would hold. About a half mile (seemed like five) down the road I came upon an emergency pull off area. With great relief I was able to get off the bike and assess the damage. The belt appeared mostly undamaged except for a section of about 2 to 2.5 inches that were missing teeth. About 8 to 12 inches after this the nylon covering of the teeth was somewhat frayed. The damaged had resulted in the belt stretching or more likely many of the internal fibers had already been broken resulting in less tension on the belt. I re-tensioned the belt to spec, 3/16" deflection @ 10 pound force with the intention of limping the last 10 miles to my campground. I made it about 10 feet before the belt broke
I was experiencing whatever the emotion is called that is beyond the calm state that is past pure rage. I had foolishly left my sprockets, chain, and tools that I could have used to fix things on the side of the road, all in the interest of saving a little space. It's now 5:30pm on Father's Day Sunday and I'm stranded in the wilderness of West Virginia hearing banjo music in the distance....
I was unable to locate a tow truck (no locals would answer the phone) or even find a truck to rent. It was my insurance companies road side assistance that came to my rescue. Of course I hadn't added it to my policy yet so I had to pay a big one time fee. I had intended to add it when I renewed the policy a month after this event. The city slicker from the call center couldn't understand where I was. He wanted an address. I had to explain to him at least a dozen times there are no addresses in the wilderness. looking at my GPS I'm on RT 16 between two county roads. I almost just gave him coordinates from my GPS. They dispached Appalachia Towing and Recovery to an intersection over 10 miles away from where I was. Thankfully the driver called me and he could understand simple directions to find me that the dispatcher could not. I had him take me to the campground where I had a few days to figure out how to get the bike back to Toledo.
Once at my destination I tried to find a one way pickup truck rental. I guess everyone in WV has a pickup so they don't rent them there. The smallest and cheapest thing I could find was a 20ft U-Haul to a friends house in Columbus, OH. Thankfully there was a Harbor Freight across the street from the U-Haul so I didn't get raped buying enough straps to secure the bike.
There is still more bad to happen before I get my bike home. At this point it has cost me much more than the belt conversion just to get the bike 2/3 of the way home. I only took it that far because it would have been nearly $200 more to truck the bike all the way back to Toledo, OH. Not to mention the additional $50-$70 in fuel.
The following weekend I drove down to Columbus to fix the bike. I put the sprockets and chain back on and went to ride to Toledo to meet my family for lunch. The front brakes felt a little weak but I didn't think much of it. I figured I'd take a look when I got home. Big mistake!
I arrive in Toledo and am getting off the freeway to meet the family for lunch. I'm on the exit ramp approaching stopped traffic at the light when I apply the brakes. To my utter horror I see my brake pad shoot out in front of me and I have no front brake! I'm on the rear brake HARD lifting every time the rear wheel locks up so I don't go down. I end up splitting the lanes between stopped traffic at the light before I am able to stop. I wait for the light to change and the traffic to clear to walk my bike to the side of the road. I walked back to retrieve my brake pad. In my adrenaline induced haze I hadn't noticed that the ground wasn't level when I put the kick stand down. As soon as I touched the front tire to try to figure out how/why my brake pad fell out, the bike tipped over into the guardrail shearing my mirror bracket, bending my windshield bracket, and scratching up my windshield! Words cannot adequately describe my emotional state at this point. I was beginning to wonder if it wasn't meant for my motorcycle to ever get home. After many expletives I retrieved my mirror and threw it in my ammo can along with the liberated brake pad. I hopped on the bike with no front brake and a missing mirror hellbent on getting to lunch and then home!
Upon inspecting things when I got home I figured out that when I had strapped the bike in the back of the truck one of the straps put pressure on the brake caliper. This moved the caliper enough for the pad to partially fall out but not enough to be visibly noticeable. This was why my brakes felt weak when I left Columbus and then shot out when I was braking hard on the exit ramp. Lesson learned: NEVER strap the bike such that there is pressure on the brake caliper!!!!
I had thought about buying another belt and selling it with the pulleys. The belt is just a standard 30mm wide 1760mm long 8mm tooth HTD belt. One can be found as little as about $60 searching for part# 1760-8M-30. Both Gates and Goodyear have these as standard belts. The belt Scootworks provided with my kit was made by some company called Speed Control. Their part# is 17608MGT2 which I assume is implying that their belt is equivalent to a Gates GT2 belt. I don't know, I've never heard of the company before. However I couldn't in good faith sell the kit knowing how poor of a design it is. Gates recently released their GT3 series belt that they claim is "up to 30% stronger" than their old GT2 belts. Also the GT series belts from Gates have a slightly different tooth profile from the standard HTD belt that is supposedly more resistant to belt ratcheting. I found one for about $80 shipped so I figured I'd give it another try. I'll let you know how far I make it before this belt breaks too!
Scootworks has moved on to a belt system based on 14mm tooth spacing HTD pulleys using a 21mm wide Gates polychain belt. Based on this companies shady practice and poorly designed product I would assume the belt is probably supplied by the cheapest available knock off of the Gates polychain belt. However assuming Scootworks is using actual Gates belts, this is a far more appropriate system. Even though the belt is 9mm narrower the Polychain belt is much stronger than the GT or HTD series belts. Also the 14mm tooth pitch belts have bigger teeth that I think should take care of the ratcheting problem. I would like to try it but not bad enough to put together my own conversion kit. Also I sure as Hell will not give another dime to Scootworks! In case you are wondering, YES I am bitter and I do hold a grudge
It has taken me this long to calm down enough to tell this story with a mostly civilized tongue.
Update 4-5-15:
I put the new gates GT3 belt on tonite. I took it or a spin and it all seemed great until I tried to align the belt. Then I realized another thing I forgot to mention that sucks about the Scootworks conversion. The pulleys do not line up!!! I forgot that's why it took me almost 500 miles to get the belt to line up! With the chain there was a slight sprocket misalignment where the rear sprocket is farther to the left than the front. With the Scootworks pulleys installed it's the opposite misalignment, the rear pulley is too far to the right. I'd hate to see how bad it would be if my chain sprockets were in perfect alignment. Even making the rear wheel crooked with the swing arm adjusters I couldn't get the belt off of the left side of the rear pulley. I ended up machining two new spacers, the ones on each side of the damper hub with the net result of moving the hub to the left about 2mm. The 2mm was just a guess on how much I needed to move the pulley over. Apparently I guessed right. Looks like I get to take the wheel off again and install these alternate spacers.
Update 4-12-15:
I had some time and put the spacers that I machined in. As mentioned above it shifts the damper hub that the pulley mounts to left about 2mm. It only took 3 tries to get the belt to center! I must have gotten real lucky since the first attempt was very close. It only takes rotating the adjusting nut about 1 flat to make the belt go to one side or the other.
I haven't gone WOT yet but I have accelerated fairly fast a couple times. So far this new belt seems fairly resistant to ratcheting.
In case anyone is wondering how I "made" my alternate spacers I had the spacer between the damper and wheel from a '90 EX500. It is the same as the spacer on the EN500 except that is is significantly longer. I machined it down so that it was about 2mm longer than the stock spacer. I then simply shortened the spacer between the damper and swing arm by the same 2mm.
I also have some ideas stewing in the back of my mind about what I want to do when this Gates belt fails too......
Update 4-28-15:
I now have about 250 miles on the new belt and I haven't had any ratcheting yet. I have gone wide open throttle but I have been careful to be slow releasing the clutch. I'll update this about every 1k miles or when the belt breaks. So far it seems like this new GT3 belt is strong enough. I'm still taking my chain, sprockets, and tools if I wander very far from home!