From: lotto@laura.harvard.edu (Jerry Lotto)
Newsgroups: rec.motorcycles.harley
Subject: Re: lane-splitting etiquette (& **** Harley questions ****)
Date: 31 Dec 92 14:41:14 GMT
	<1992Dec23.184102.9663@megatek.com>
	<1992Dec30.204916.14840@rtsg.mot.com>
Organization: Chemistry Dept., Harvard University
In-reply-to: svoboda@rtsg.mot.com's message of 30 Dec 92 20:49:16 GMT

>>>>> On 30 Dec 92 20:49:16 GMT, svoboda@rtsg.mot.com (David Svoboda) said:
Dave> Chains are better now.

So are belts.

Dave> A light lubing is required every few hundred miles on an O-ring chain

Belts don't require any lubing.

Dave> (takes about 30 seconds, if you have a centerstand, which is stock on
Dave> nearly every chain-driven bike)

This is rec.motorcycles.HARLEY.  Find me ONE chain-driven HD with a
stock centerstand.  Hey, maybe you found the reason that Harley felt
obligated to convert all models to belt drive!

Dave> It is a good idea to clean off the grime every 1000 miles or so
Dave> in a particularly dirty environment.

In all cases, regardless of the drive type.  Admittedly, this is more
critical for chains.

Dave> Replacing the chain and both sprockets runs under $150.  I can
Dave> do the entire job in under an hour

If you opened a shop that relied on making a profit by replacing chain
and sprocket sets for a fixed rate - say $300... you would go broke
pretty quickly.  You happen to have a type of motorcycle on which this
is a simple job.  That is not true of all brands, Harley or other.
Try wrenching on the older style FXRT enclosed chain drive for fun :-)

Dave> a chain to, I expect you subject the belt to.  Belts die, too, and
Dave> are MUCH more expensive (time and money) to replace.

The new Dyna frames do not require that that swingarm come off to
remove a belt.  The effort required to change belt and sprockets on
these bikes is similar to a chain drive bike.  Belt parts are
comparable cost or less expensive on a $/mile basis, assuming EITHER
worst case or best case maintenance.  Worst case is more typical and
that is the situation where belts offer the greatest advantage.

Dave> Is it even possible to change the drive ratio, with a belt?

Sure.  The process is identical to chains.  Change one or both
sprockets and use an appropriate size belt to center the tension
adjustment.  No belt change required for +/- 4 teeth (about).

In reply to :"My Harley mechanic tells me their belts generally last
              75,000 miles with a single adjustment"

Dave> Okay, 1-1/2 times as long as chains, under MUCH less typical stress.

You missed the boat on this one Dave, the comparison being made above
is on the SAME TYPE of motorcycle with typical (poor) care.  Belt
failures are not often stress related, they typically fail because of
damage long before they exhibit significant wear.  If you treat a belt
half as good as you treat a chain - regular cleaning, tension
adjustments, etc, the belt can give you 100,000+ of service.  Add up
the time and labor and lube over the life of the product and the cost
difference shrinks.

This thread has been about HD belts on HD motorcycles.  The original
poster wanted someone to justify the corporate decision to develop
belt drive before the fact, but I don't think that anyone here can
provide that perspective.  We do have is 20-20 hindsight, and in
retrospect, the conversion to belts was a GOOD MOVE (tm).  I can't
think of a reason to want a chain driven motorcycle again unless the
power output of the motor exceeds the belt's capacity.  Modified
belt-driven big twins which attain over 100 HP have not tipped the
scale yet.  The torque figures are probably more significant with
respect to belt stress, and V twins provide plenty of twist to the
teeth.

I don't know what an actual stress limit comparison of the two systems
(modern belt vs. modern chain) would reveal.  Anyone out there abuse
drive systems on a Dyno for a living :-?

--
Jerry Lotto <lotto@lhasa.harvard.edu>         MSFCI, HOGSSC, BCSO, AMA, DoD #18
Chemistry Dept., Harvard Univ.  "It's my Harley, and I'll ride if I want to..."
Newsgroups: rec.motorcycles.harley