Aftermarket Rear Gear for GL1800/F6B?

kwthom

Rider
Premier Member
IBA Member
#1
Aftermarket Rear Gear for GL1800/F6B?

Has any of the members here see this YouTube video about a guy who is making gear sets for the final drive?


It is supposed to lower RPM's by ~15%. Some of the comments in the video imply a pretty decent uptick in fuel economy (290 miles on 6 gallons of fuel?) and quite a bit of interest.

Comments?
 
#2
I have not seen that, but it could be a good trade off to avoid adding a fuel cell. If I could average 275 miles per fill up, or even 250, I'd be pretty well pleased compared to the current range. Are you considering trying it out?
 

kwthom

Rider
Premier Member
IBA Member
#4
Considering it...but the cost of a good fuel cell and other accoutrements to install is roughly the cost of this rear gear.
 

Shawn K

Professional Cat Confuser
Premier Member
#6
For what it's worth, I noticed that Henry's own R&D testimonial quotes an MPG figure that isn't that far off from stock. I routinely get in the low 40's at a long, steady-state 60 mph. My experience has been low-mid 40's at 60 mph, and high 30's at 70 mph. (Click on my Fuelly link for verification.)

In my own anecdotal experience (note the qualification), it takes X-amount of horsepower to push a GL1800 through the air at Y-speed. The rpm of the engine doesn't change that fact. Whether you're making that horsepower through spinning fast with a small throttle opening, or spinning slowly with a larger throttle opening, the horsepower needed to push you through the air at Y-speed remains constant.

From where I sit with my own (admittedly) limited understanding of engine design, it seems to me that any mileage gains realized are likely to be from reduced internal friction due to lower engine RPM. Which is fine, but I don't hang my hat on it. There are lots of things that can affect an engine's internal friction besides rear drive ratio.

I'm not for or against the altered rear drive ratio. I'm just saying that I found it interesting that Henry's own site doesn't quote someone who has seen mileage gains.

Draw your own conclusions.

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BigLew55

Premier Member
IBR Finisher
#8
When the gearing was updated, was the speedo recalibrated? If not, a user might just think that they are getting better MPG, when in reality, they are not realizing the gain that is promised.

Most MPG calculations involve ODO/Gallons. But the ODO on most modern vehicles is a calculation of rotations somewhere in the powertrain, and usually before the final drive or tire.

For instance, a 6% higher final drive ratio that nets a 4% calculated improvement in MPG actually cost you 2% if that calculation was not based on an ODO that was calibrated before and after.
 

Shawn K

Professional Cat Confuser
Premier Member
#9
That's way too expensive for a 'possible' benefit. Fuel cell is less cost.
Agreed.

I also found it humorous that Henry's site mentioned "reduced engine wear" as one of the benefits. With all the examples of GL1800's with over 300,000 miles on them, it seems like a minimal benefit at best. Keep clean oil in them and the dang things are as close to bulletproof as any motorcycle engine can be.

Plus, I started thinking about the cost of fuel vs. mileage (allegedly) gained vs. ROI, and concluded that you'd have to either recover serious-arse mileage or ride your Gold Wing until Gabriel blows his horn before you'd make up the cost of the new rear drive. And that's just to break even.
 
#10
Agreed.

I also found it humorous that Henry's site mentioned "reduced engine wear" as one of the benefits. With all the examples of GL1800's with over 300,000 miles on them, it seems like a minimal benefit at best. Keep clean oil in them and the dang things are as close to bulletproof as any motorcycle engine can be.

Plus, I started thinking about the cost of fuel vs. mileage (allegedly) gained vs. ROI, and concluded that you'd have to either recover serious-arse mileage or ride your Gold Wing until Gabriel blows his horn before you'd make up the cost of the new rear drive. And that's just to break even.
And the model isn't even in production anymore. I've been thinking of going a different direction soon. The Goldwing has been the best for two up and comfy iron butts. But I'd like to get something for our local group adv rides and still be able to slab some iron butts here and there. Was thinking super tenere or Africa twin dct. Thoughts?
 

Shawn K

Professional Cat Confuser
Premier Member
#11
Given those two options, I'd go for the Super Tenere. Not only am I a big fan of shaft drive for long-distance riding, but the Super Tenere is a pretty darn solid bike. Paul Pelland thrashed the bejeezus out of two of them with nary a whimper. It's still on my short list of Bikes I'd Own If I Didn't Have This Gold Wing.