If it ain't broke don't fix it. Weather the new tranny is stronger or not does not matter since the old one works fine. BMW, Victory and others have a 6 speed so HD wants to offer one as well. Since it offers no OD and ends up the same ratio in the end, it offers nothing IMO. It all ends up the same with one more gear to go through. I will keep my 5 speed, I hope the 6 speed works out. I just don't care to be part of the test run. Been there and done that. In Victorys case, quiet means nothing since the engine sounds like a wash machine anyway. I needed loud pipes just to try to wash out all the engine noise. Still did not work. Good luck with whatever you ride!

 

Show me where, in the final ratio, 6th gear, on the new 6-speed, the engine is turning the same rpm at the same speed in a 5-speed. You can't. The gearing is not the same. It's not a true over-drive because HD changed the ratio of the other five gears, but 6th is still taller than 5th on the old tranny. I see guys screaming that the new tranny needed a "true OD", and two things always come to mind -

1. Those guys now own a 5-speed.
2. At 65 mph, if I shift into 6th gear I am damned near lugging the engine on my bike. You make 6th any taller and you'll need to be running 85 to use it.

If it ain't broke don't fix it? Then why aren't we all riding 4-speed, hard tail, EVOs? There is nothing wrong with those bikes, right? Like it or not, technology marches forward. Next time you see a guy with new Dyna, try to bum a ride, so you can get some real riding experience with the new transmission. HD propaganda was mentioned earlier... before I bought my bike, I read all the reviews.. and I can honestly say they were all right on the money. The new transmission is super smooth. 6th gear kicks a** on the highway. Put it in 6th and cruise at 80mph and the motor isn't even trying. You oughta check it out.... you might be surprised.

 

OK, folks, don't let this head any further south than it is right now.

Differences of opinion are fine. Keep it civil.

Out of curiosity, how does the motor spin less rpm at highway speeds, since the final drive ratio is still 1:1, and not an overdrive? What else did they change?

Mega, where do you work? I take it you're an HD mech from a couple of things you've said.

I'd dang sure like a 5-in-4 tranny, with 5th an overdrive. Make it able to easily bolt up to a Sloptail frame/primary & put a kicker on it. And make it a Baker, not a Rev-Tech.

And an aside: Straight cut gears are stronger than helical cut, every thing else being equal. If you over-design the helical gears, then it becomes a moot point.

Finally, I repeat: OK, folks, don't let this head any further south than it is right now.

Differences of opinion are fine. Keep it civil.

 

I don't know. That's why I asked to be shown. They changed the primary gearing too and I'm not a math wiz, so I can't figure it all out. All I know is, I've ridden quite a bit on an '05 Dyna and an '02 FXST, plus a little time on an '05 EG. I know my bike is turning lower RPMs at 70mph in 6th, than the '05 Dyna does at the same speed in 5th. Yet I keep reading on the net that the final drive ratio is the same on both bikes in highest gear. It doesn't add up to me. Plus, the guys who own the other bikes have ridden mine and they agree. Both of them want 6-speeds now. So it doesn't add up these bikes end up with the exact same final drive ratio. I literally have to be running 65 to use 6th gear without lugging the motor. Several magazine and net reviews have reported the same thing.

 

I didnt change any subject at all, let me ask you this: Exactly what IS the "torque carrying capacity" of the new 6 speed? Answer this before you even attempt to answer anything I ask following this question. Can you even translate what "torque carrying capacity" means from HD's interpretation? The new tranny may be stronger, but in what way really? Strength could mean a hundred things, and Ill explain this later on in my reply. Does strength really translate into a more durable product? Not always.
The new crank side case Roller bearing HD uses in all the Twin cams from 03' to all current production(including your 06' model bike your ride) models have a superior radial load carrying capacity to the older style Timken bearings, but the old style Timkens are far superior in axial loads to the roller bearings and thus can take the everyday abuse of a performance engine without issue. And HD exploited this fact when they made the change. Now anyone who is even half serious about performance will send their cases off to have the old style Timken crank bearing installed into their case to the tune of $350 so when they do an upgrade they dont have to worry about catastrphic bearing failure which is pretty common and very costly. Strength is a relative term and there are more ways than one to determine real world "strength and durability".

I think you need to do a bit of learning on the advantages and disadvantages of helical and straight cut gears but in short: In short, helical gears operate quieter than straight cut. Straight cut will 'whine' the faster they go but offer both 1. More directional application of force allowing for less power loss. and 2. Higher acceptable loads until failure. Basically making the transmission stronger and more efficient.
This is a known and proven fact. Quality straight cut gears are also more EXPENSIVE to mfg. HD is going to helical cut gears not just because they are "quieter"(which is their marketing ploy, but not the only reason why they are making the switch)but becuase they are saving some pretty significant coin on the new gearsets. Since helical gears have more teeth in contact with each other at all times, they can use a cheaper possibly weaker metal to produce the gears since the load will be divided and never be placed directly on a single tooth. Helical gears do have a few big downsides. They have major thrust loads, thrust loads make the gears tend to move away from each other laterally. Hence the reason for the larger bearings and the stronger case HD is using in the transmission sets. They have to because of the side loads. But are they of sufficient size and strength to endure the thrust load long term and to match the gears sufficently? That question won't be answered for awhile. Lets wait and see. In the mneantime Ill take the proven reliability and durability of my straight cut gears which have

 

I feel no need for a 6th gear. The 88CI engine does not have the power IMO to need it. You like your 6 speed, good for you. I am happy for you and I hope it lasts forever. I am happy with the 5 speed, period. I have seen too many people get burned on new upgrades. Not that upgrades are not better and we sure need to move forward as you stated in your earlier post, I will just wait to see how they work out. Ride safe and enjoy your 6th gear.

 

I don't even know why I am replying, because your opinion means nothing to me. It's a waste of time to argue with you. That's not an insult, BTW... it's just that my mind is made from my experience with the bike. No words can change that. I read all about helical cut gears before I bought my bike, so none of that stuff is news to me. I read the reviews, I read all the "Harley propaganda", and after riding the bike for nearly 3000 miles, I agree with it. As a matter of fact, I think they could have raved about it more than they did. I am a believer in the new 6 Speed. So the guy who started this thread can either listen to a guy who owns one, or he can listen to someone who doesn't.

The one thing I am interested in, is this final gear ratio thing. It doesn't add up to me. If you could quote a reliable source that says the 5 speed and 6 speed have the same final ratios in high gear, after the primary gearing is factored in, I would appreciate it. I've read this in several internet postings and it doesn't match my real world experiences. Not saying it can't be true, just saying that 5th on an '05 doesn't feel like 6th on an '06.

 

I figured you would avoid the rest and most important part of my last thread. Not to mention get stumped with the first simple question.Hey, What do I know? Only been working on hundreds of HD bikes(both street and track) over the last 15 years. And btw, my "opinion" is based soley on pure facts and experience. Maybe before you spout off on technical opinions though, you should have a bit more to back your words up other than what you read in a few magazine articles in your spare time. You should have left your original post at "slick shifting......I like it". You went wrong when you included "strongest transmission HD ever put out", thats what killed you and any technical credibility you may have posessed prior to this thread.

Final gear ratio thing? You seem to be overly confident on your knowledge of HD transmissions, yet your having problems figuring out a simple math equation on how to calulate FD. I would tell you, but I guess you don't consider someone like myself as a "reliable source", so why bother? LOL! Guess you'll have to flip through back issues of AIM or Hotbikes to find that answer............

 

this thread is blowing my mind! I thought we were all HD bikers and enthusiasts! If the dude likes his 6 speed -- great! If the other dude thinks they are gimmicky -- great! Time to get on the road, enjoy the wind in your face and remember why it is we ride. Just my 2 cents....

 

Great thread! One of the livliest I have read in a long time. Sometimes, when people feel strongly about something, things get hot. But thats not the end of the world. Dont know a lot about the relative tech merits of the 6 and 5 speed, but having ridden both, all I can say is that the 6 speed is darn smooth shifting, no where near as clunky as the other one