Belt Drive - have you completed or found good resources for a conversion ?

[ohgood]

Since the final drive for the gs can be figured easily enough -  has anyone tried a kit or homebrew to convert the gs to a belt drive ?

I was thinking while ordering a new chain, "Hey, a belt drive would last a long time with the gs's limited torque !" and starting looking around. My google-foo is lacking lately, so maybe someone else has a few good links to provide, or insight into how crazy an undertaking it would be ?

It shouldn't be much more than a couple of ribbed sheaves and a belt (the length might not be easy to find) and a little welding for a tensioner on the swing arm.

Please, this isn't a debate about chain vs belt, why harley davidson's suck, etc, I'd like to find good information and no flamewars

[groff22]

That would be cool and I'd like to see it done. Like a Buell Blast, but with more power and better looks.

Sounds like might need to fit a diff swingarm, wheel, space housing the countershaft sprocket could get messy...

Cheers,
J

[Garethbourne]

Hi, though I have never looked, for a belt conversion for the Suzuki, I did look around for a drive belt conversion for the Drifter, and I found a company in the states that's called scoot works, you could give them a try, as they do a lot of parts for a lot of bikes,

http://www.scootworks.com/

[The Buddha]

Done this several years ago. In spite of werase's constant ribbing.
The Irony of ironies is that, Scootworks is in Zebulon NC by the border with VA and like 20-30 miles from werase's house, and ~120 from my house. The guy offered to let me rummage through his pile, but I foolishly never went there. The rear sproket is easy. Front is the problem.
Anyway, a 8mm pitch Poly chain GT2 belt with a 36 tooth or 38 tooth sproket can be machined up and bolted to the sproket. Then set a rear and line it up.
There comes the next problem. The circlip on the counter shaft holding in the sproket.
Drill and tap that for a bolt.
Cool.
Srinath.

[GeeP]

I've thought about it, but I'm not going to do it to my GS.

When an SV shows up in the garage, that's a different story...   

[ben2go]

I ride my bike so much,it'd be benificial to me.No more cleaning and lubing a chain every week.The GS doesn't have enough power to slip or stretch a poly chain/belt.

[yamahonkawazuki]

meh sporties/hds dont suck but thats another debate. if it could be done inexpensively,  then sure id be all over it. BUT if its major buckage then no. perhaps the guts from a blast? ie the rear sprocket/ and the front along with belt and tensioner?

[ben2go]

meh sporties/hds dont suck but thats another debate. if it could be done inexpensively,  then sure id be all over it. BUT if its major buckage then no. perhaps the guts from a blast? ie the rear sprocket/ and the front along with belt and tensioner?

I thought about that but that huge rear pulley is f'in UGLY.

[Kasumi]

If i bought another bike i would be tempeted to get one with belt drive. I was thinking about a BMW F800S theyre gorgeous and have beltdrive.

[Foximus]

Id do it if i didnt have to go way out of my way to find pieces to make it work....    Dont get me wrong I love mixing parts and getting creative but I gotta pick my battles and that wouldnt be one of them.    If i had the part numbers and all i had to do was order it sure.... 

Otherwise Id be more content finding a way to put a GSXR head on this motor or something.

[gsJack]

If i bought another bike i would be tempeted to get one with belt drive. I was thinking about a BMW F800S theyre gorgeous and have beltdrive.

Kinda pricey for me, I've been thinking about a Savage aka S40 as a possible light weight low seat bike for my old age when I get there.      Only current Suzi I can think of with a belt drive.   

[ohgood]

Thanks for all your input. I put out a few emails to see if there were any vendors interested in doing the hard work for me. We'll see.

If it was possible to get together a by-the-numbers kit, I think it would take off fairly well. The gs has a low amount of torque, few insane riders (well, some of you anyway) and it would make touring quieter and less of a pita in inclement weather.

This should be fun . 

[sledge]

Synchronous timing-belts and pulleys are whats needed, vee belts will slip at the first sign of heavy rain.  They are freely available in industry and easily sourced but the problem is getting them to fit within the space constraints found on a bike together with keeping the belt at a constant tension as the swing-arm moves. Too tight and it becomes stressed, too loose and it slips teeth. Alignment is far more critical than with a roller chain, any misalignment and it will move up against and wear against the pulley shoulders. Bikes designed with belt drive in mind tend have rear suspension designed to keep the belt tension as near constant throughout its travel as possible, idealy the swingarm should pivot about the O/P shaft center. Any advantage a belt drive conversion may have over a chain is going to be outweighed by the difficulties in making it fit and operate with reliabilty, and lets be honest...................if it was easy or beneficial everyone would be doing it.

http://www.bandousa.com/html/industrial.html

[bombadillo]

is it seriously that hard to change out or tighten a chain in the first place.  Just get a cheap roller chain with a master link style closure and you can change a chain in a few minutes for 35 bucks.  Not that hard and lube takes all of a whole minute.  (Can we say warmup time) 

[yamahonkawazuki]

meh sporties/hds dont suck but thats another debate. if it could be done inexpensively,  then sure id be all over it. BUT if its major buckage then no. perhaps the guts from a blast? ie the rear sprocket/ and the front along with belt and tensioner?

I thought about that but that huge rear pulley is f'in UGLY.

true, well i guess  it would depend on the bike it was sitting on, but eyah on a gs, yes it is teh ugly 

[GeeP]

Ohgood,

It wouldn't be terribly difficult to make up a set of custom pulleys.  I would make them in three pieces.  Left flange, right flange, and body/cog.  The flanges would be rings that bolted to the periphery of the body/cog.  The belt manufacturer will have plenty of application data to guide you in design.

The cog could be banged out on a shaper with some offhand ground tooling.  You DO have one sitting in a dark corner, right?  If you have a nice sturdy boat anchor of a rotab, like a big Kearney and Trecker, you're good to go.  Use the rotab in the vertical orientation to space the cog teeth and plunge cut to depth.   

Barring that, I'm sure the tool manufacturers have horizontal milling cutters with the correct profiles for timing belts.  Obviously, you'll have to make a mandrel and use a super spacer with a tailstock to gain clearance for the cutter to work.

As sledge says keeping tension is very important.  Have a look at how Buell does it on their bikes.  An idler in the right place on the slack side of the belt works for them.  I don't think that the swingarm geometry would cause much of a problem though.  1" of chain slack is what?  Maybe .02" change in distance between the drive and driven sprocket centers?

[ohgood]

Ohgood,

It wouldn't be terribly difficult to make up a set of custom pulleys.  I would make them in three pieces.  Left flange, right flange, and body/cog.  The flanges would be rings that bolted to the periphery of the body/cog.  The belt manufacturer will have plenty of application data to guide you in design.

The cog could be banged out on a shaper with some offhand ground tooling.  You DO have one sitting in a dark corner, right?  If you have a nice sturdy boat anchor of a rotab, like a big Kearney and Trecker, you're good to go.  Use the rotab in the vertical orientation to space the cog teeth and plunge cut to depth.   

Barring that, I'm sure the tool manufacturers have horizontal milling cutters with the correct profiles for timing belts.  Obviously, you'll have to make a mandrel and use a super spacer with a tailstock to gain clearance for the cutter to work.

As sledge says keeping tension is very important.  Have a look at how Buell does it on their bikes.  An idler in the right place on the slack side of the belt works for them.  I don't think that the swingarm geometry would cause much of a problem though.  1" of chain slack is what?  Maybe .02" change in distance between the drive and driven sprocket centers?

Wow, I hadn't considered cutting it myself. I've only cut 3 gears in my 15 years machining experience. I don't think grinding the tooth profile on a woodruff cutter would be a big deal, nor would the setup of the dividing head. If I worked in a machine shop anymore I'd do one on a Saturday. Unfortunately I've given up on trade completely as an occupation. As much as I love the smell of sulfur oil and hearing quarter sized chips zing off a LeBlonde, it just cannot support my family as I wish it could. (BIG TEARS)

I was considering off - the - shelf cogs and a possible adapter for the drive and driven bits. I wasn't considering a V-belt as the mentioned bit about rain. A long life type (radiussed teeth) belt would last a NICE long time even in the elements on the gs. Alignment would need to be spot on of course, but a simple tight string/laser setup should make it fairly easy. Pre-load of the drive would be something to wonder about. Every timing belt I've seen was a fairly snug affair, with some having no preventers of lash at all. If a timing belt can last 80,000 miles in a controlled environment, and with little load other than the mass of the camshaft, a similar belt setup should easily be able to last 20,000 miles (average life of a maintained chain) easily.

For that matter if the belt is cheap enough, just replace it on every other rear rubber change.

[GeeP]

Ohgood,

Sorry to hear about the machining thing.  I'm not suprised and I don't blame you for leaving.  It takes a lot of work to become a journeyman machinist and for what?  $12.50 an hour with no benefits.  There are still a few niches where the pay is good.  Getting into a powerplant shop (especially nuclear) is one of them.

I could see a modified woodruff cutter working, but I don't have the patience on a tool grinder for that.     A fly cutter mounted in a horizontal or universal machine could work too.

The Hybrex belts on Buell motorcycles are tensioned with a spring-loaded idler on the "loose" side of the belt, roughly below the swingarm pivot.  The spring adjusts the tension.  The belts are rated "for the life of the motorcycle", but are generally replaced at around 30,000 miles.  About as often as a well maintained chain.

Edit:  I forgot to mention.  There's a guy on the SVrider board that has built a couple of conversions for the SV.  His father owns a gear service, so he made his pulleys on a Fellowes gear shaper as I recall.  He's put about 25,000 miles on his conversion with no reported problems.