5th gear - overdrive?

I've heard a few guys on here refer to 5th gear as "overdrive". Though I think I can guess what they mean, I'd like to be sure - so what, exactly, do you mean by that? To me, when the bike is near 50 mph or more, it "wants" to be shifted into 5th gear. Some have said they drive in 4th gear at even faster speeds and do it for long periods of time; this is okay for the engine?

PS - I think you guys who ride these little bikes at 75 mph or faster are nuts - not dissing you, even admire your balls, but Jesus, the bike does not feel stable to me at that speed, especially if there is wind or other mitigating factors (heavy traffic, wet roads, etc.).

Thanks,

Keith

[Sarris]

You are probably referring to the bantor surrounding the 16 tooth front sprocket change. With that
mod done, you will reach your max speed in 4th utilizing 5th gear as a cruising or "overdrive". It's only because
the 16 tooth changes the powerband a bit.

Also, 75 mph??? You shittin me?? At 6'-1 280lbs. I'm lucky to keep 65 to 68 mph w/ no headwind. But some
physically smaller folks have reported over 80 mph. I'll take the Harley if I need to go that fast.

:2tup:

Thanks, Sarris, I did forget that those mentions of "overdrive" were related to the 16T mod. BTW, I only weigh 160 and I still think anything over 60-65 feels unstable to me, especially now with a bigger windshield. But, hey, I'll live vicariously through the speed demons (but be safe, boys)!

Keith

[alanmcorcoran]

km, I think Easy(?) and others have referred to it as an overdrive, not in the strict technical sense (that output of the tranny is greater than input) but in that:

1) It's the last gear.
2) It's where you can get some top end speed, but it's got no torque.

Basically, you want to be already moving pretty good, on a flat, smooth road, and then, put it in fifth and go for it. If you are climbing hills or fighting wind, you might as well leave it in fourth, cause otherwise you'll probably be slowing down.

Re riding 75. Mine will do it, but only under near perfect conditions. (Flat, smooth road, maybe a small tailwind or behind a semi.) Actually, if the road is smooth asphalt, my bike is very stable at 75. There just aren't many roads around here where the smoothness, the flatness and the straightness all combine. Ironically, most of our high speed roads have pretty shitty surfaces. I weigh about 178. Generally I am happy if I can keep at or just above the speed limit (65.)

When I first got the bike it was not as fast as it is now. I often had to leave it in fourth to maintain 60 or better on the freeways. There are other threads on here that talk about redlines, limiters, and riding WTFO (Wide The F*ck Open) all the time. Some anecdotal evidence seemed to suggest it wasn't the best thing for the bike, but I don't think there's been any science presented. To be honest, that "any minute now I think I'm gonna pop" sound the GZ makes when it is hammering along at 65-70 is one of the reasons I got a bigger bike for that kind of riding.

[Water Warrior 2]

:popcorn: :popcorn: :popcorn: I am just going to sit back and let Easy explain overdrives.

[JWR]

I could do the :

1 to 1
or
.81 to 1

but this is too much fun....


Easy would just correct me anyway. :roll:

[Easy Rider]

Some have said they drive in 4th gear at even faster speeds and do it for long periods of time; this is okay for the engine?


No, not for long periods of time.

One definition of "overdrive" is "to be used at highway speeds to allow the engine to turn slower".
Your observation that it feels like it is needed above 50 fits that definition pretty good, I think.
It is not a real overdrive but it functions pretty much like one.

And yes, the effect is more pronounced with a 16T front sprocket as you don't feel the need to use 5th in most city situations (below 40-45 mph).

How's that, WW ? :cool:

[JWR]

Hey Easy, is someone else on your computer????

[Easy Rider]

Hey Easy, is someone else on your computer????

Why do you ask?
(Maybe I don't want to know!) :roll:

[alanmcorcoran]

Seems like you are taking your medication again! :whistle:

(can I get some?)

[Easy Rider]

Seems like you are taking your medication again! :whistle:


I wish. :retard:

[primal]

I real overdrive gear is one where the engine actually turns SLOWER than the wheel. Whether the 16T sprocket actually accomplishes this or not I dunno.

[Easy Rider]

I real overdrive gear is one where the engine actually turns SLOWER than the wheel. Whether the 16T sprocket actually accomplishes this or not I dunno.

No it doesn't. Because of a relatively large wheel and small motor, I don't think any motorcycle has a true overdrive.......except maybe a few of the land yachts.

And I think your definition needs a slight "tweek". Overdrive is when the drive shaft turns faster than the engine. The final drive ratio in the rear end determines how fast the wheel actually rotates. That makes determining "overdrive" a bit tricky for vehicles with an integrated transmission......like front wheel drive cars and motorcycles.

[Water Warrior 2]

Let me try for a bit of input. The bike sprockets and chain would be in a similar category as the rear end(differential in a cage) or the transaxle in a front wheel drive cage. My cage has a 4.11 to 1.0 rear end ratio. The drive shaft turns 4.11 times for every turn of the axle. Just to muddy the waters now we go to the internal gearing of the transmission in a bike. The GZ has 5 gear ratios that we can relate to during every ride and shift. There is also another set of internal gears and their ratio. There is another gear on the shaft(along with the 5 gears)that drives a gear mounted on the output shaft that we all recognize as the front sprocket shaft. The driven gear and it's drive gear also have a ratio sometimes referred to as an internal gear ratio. All in all it is a numbers game and best left to the designers for the best compromise in power, speed and reliability of a given machine.
Now I will sit back with a coffee and try to understand what I just said. lol.