Way back when, crank runout tolerances were much tighter than what was allowed more recently. The only way to know is to check it. Too much runout and the gears will destroy each other. Cam chain gears don't mesh therefore don't require such close tolerances, therefore are cheaper for the MoCo to produce.

 

Switched to gear drive so when people hear the bike running and look horrified at terrible sound coming from gears, I can quote the dealership mechanics..."they all do that."

Seriously - what big sky road glide said...

 

the whine is very little when its cold, once warmed up there is none.

Toby

 

There's no real advantage for street bikes.

 

Indeed! I've ridden shovels and Evos since the '70s and Sportsters and Buells a bit less. The Sporty-based engines have countless gears in the cam chest and don't intrude while riding.

 

I just installed Andrews 37 geared cams, no whine at all.

 

A local indy I've dealt with had an interesting demonstration setup in his shop. He had two cam chests set up, one with a gear drive and one with the original chain drive. Each had a small hand crank on it for folks to turn. The amount of force required to turn the chain drive setup was huge compared to the gears. All the tensioner pressure on the chain really puts a load on the system.

 

They simply hold the tune more precisely. Chain drives even with tensioners are not as precise as they drift some when under acceleration then shifting some slop occurs with the change in rpm.

 

Are you two following each other around Canada?!

Good points from both of you. As an engineer I've taken a keen interest in what the auto/bike industry has been doing in recent years to reduce noise and exhaust emissions, which includes reducing parasitic losses. It seems the additional power required to turn the cam tensioners must have been considered worth it, presumably for the reduced noise.

 

I have gears in my 02.....No whine, but a funky sound very hard to describe.
It was pretty much very quite and I switched to dino oil and the sound is more noticeable.