Whether it's the DRZ400 or the Jeep TJ or the Samurai or the Land Cruiser or the HD Sportster or any other vintage-to-almost-modern vehicle with a five speed transmission it seems like the majority of operators are constantly clamoring for a sixth gear.
Are they? And if so, why?
Each one of these mills has much power potential hidden away behind the factory's lean carb settings, restrictive exhaust, poor head flow, and low compression ratio.
Everyone knows that such factory machines have to be strangled a bit, often in fact a lot of bit, to pass the emissions regulations for the markets in which they're sold, and so no factory engine is truly at its peak performance level.
But if an engine is operating at its best capacity won't it be making enough broad spectrum power from idle to redline that a 5 speed tran coupled with higher final drive gearing would essentially be the same thing as a strangled engine that has to use a 6 speed to compensate for the strangled power?
Do you mean higher gearing, as in numerically higher (ie. more revs for a given road speed)?
I've only ever owned one car with a 5 speed, and 5th gear was pretty much just for highway use. I'm not sure what advantage, if any, a sixth gear would offer a vehicle. I think the big reason we have so many gears now is really because of traffic, not for any inherent mechanical need. The old Ford Model T, with 20hp, got by with a 2 speed transmission. But there was no traffic in 1908. It didn't bother anybody if you were gradually losing speed going up hills in top gear, then had to downshift to 1st to make it the rest of the way, grinding up at 10mph. The car didn't need an intermediate gear, even if driver's may have liked one. By the 1960's, traffic was such that 3 speeds was becoming a bit of a problem. By the 80's, 4 speeds wasn't sufficient for the demands of traffic. There is a hint of planned obsolescence about the whole adding more speeds to transmissions every decade, but really it's because the traffic, not the vehicle, demands it.
