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Good
point about the pulleys. My statement about never having a failure with a
serpentine wasn't entirely true. I did have the tensioner pulley on a Ford
Powerstroke fail. It was still under warranty and I was only ~a 1/2 mile from
the dealership so I just drove it over. They replaced the belt with the new
tensioner pulley but I kept the old one as a spare because there was nothing
wrong with it (still have it).
But
Marvs post does bring up something important about belt tension. Belt slippage
can lead to premature belt failure. Most older automotive V-belt installations
have no automatic tensioner, while the newer serpentine belts usually do. This
could be a large factor in the increased life of serpentine belts since they
should always have the correct amount of tension. In the case of my aircraft
alternator belt, which I have a multi-rib belt it doesn't have a tensioner
pulley so it will not have any greater chance of proper tension than if I'd
used a V-belt.
Belt
design has also improved dramatically as well. I recall in the late '80s we
would never go on a snowmobile trip into the mountains without bringing at least
2 spare drive belts and we often needed them. My sled today has close to twice
the HP with much higher load due to increased traction and yet I've never blown
a single belt. Of coarse this is also helped by much better clutching
design.
So
Tracy is definitely correct in his statement that reliability isn't a big reason
to eliminate the belt driven accessories, but IMHO weight reduction
is.
Todd
Good points. I can't get excited about eliminating belts
because I have never seen even a hint of a problem with them *
when properly installed *. This includes all experience with cars and
aircraft.
I *have* seen them fail when pulleys were not properly aligned, debris or
damage caused the pulley to wobble, they were overloaded, or other
installation errors.
Belts are a very mature and reliable technology. There may be
good reasons to replace a belt but reliability is not one of them.
Tracy Crook
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