Rear End Gear Change

[JimLindenberg]

Anybody ever thought of or changed the rear end gear ratio to bring the RPM's down??

2016 GL1800 with Roadsmith HTS1800

[Lee H. Mann]

Anybody ever thought of or changed the rear end gear ratio to bring the RPM's down??

2016 GL1800 with Roadsmith HTS1800

Roadsmith currently uses a 2.61:1 (I believe) ratio for the GL1800. You probably have the 2.93:1 that was previously used prior to the 2019 models. You will then need a 'speedo healer'.

[JimLindenberg]

Roadsmith currently uses a 2.61:1 (I believe) ratio for the GL1800. You probably have the 2.93:1 that was previously used prior to the 2019 models. You will then need a 'speedo healer'.

At around 65 mph I'm at 3,000 RPM. What is your RPM with the 2.61:1?

[Lee H. Mann]

At around 65 mph I'm at 3,000 RPM. What is your RPM with the 2.61:1?

I don't have a Roadsmith but the change is around 10%. 71mph is the new 65mph @ 10%.

[JimLindenberg]

I don't have a Roadsmith but the change is around 10%. 71mph is the new 65mph @ 10%.

Thank You for the info

[Burnerboy]

Just yesterday (10/23/20) I rode with another Goldwing (stock two wheel'rrr) and I have the R/smith trike (Goldwing) at the gas station, we both filed up at the same time and each of us zero'd out our odomitors........... later on in the ride we would check our O/D's to see the difference................His was always 1.5 miles more than mine, is the difference's because of mine is a trike??

Ronnie

[trikeman]

Yes. You can expect a decrease in MPG when triking a motorcycle. Most trike conversion companies have researched the gear ratios and have matched the gear ratio that gives best performance and fuel mileage to each model and make.

[rhino 2]

Yes. You can expect a decrease in MPG when triking a motorcycle. Most trike conversion companies have researched the gear ratios and have matched the gear ratio that gives best performance and fuel mileage to each model and make.

I think Ronnie was talking Indicated miles traveled on the odometer... And not Miles Per Gallon......

....

[trikeman]

👍🏼

[cScjhb]

Odometers and speedometers are notorious for being inaccurate in Goldwings. I have ridden with many different trike brands as well as 2 wheel Goldwings for several years. Very few will ever agree on distance traveled much less MPG even though we all fuel up the same place and ride together. At one time I installed a Valkyrie rear tire on my 2 wheel GL1800 and, because of the larger tire aspect, my speedometer was almost dead on. But handling suffered a bit. I eventually went back to OEM spec. tires and added a Speedo-Healer to that bike. If memory is correct, I believe there was a 6.5% correction required to make the speedometer accurate. But, I did notice that my odometer was then logging slightly fewer miles than I was actually traveling.

I know my CSC trike also has about a 6% speed error. I will look into the possibility of installing the next larger size tire aspect when the tires need replacing. Currently my speedo indicates I am doing 67 MPH at 2800 RPM but my actual speed is closer to 64. I think the GL1800 has enough torque to carry the same speeds at 200-300 less RPMs. Hope this helps..... Jim

Additional Info.....

My trike has a 3.0-1 rear end

The spec calls for 205/70R14 tires having a diameter of 25.3 inches rotating 798 times per mile.

I have installed 205/50R17 tires having a diameter of 25.1 inches rotating 805 times per mile

If I change to 205/55R17 tires the diameter is 25.9 inches and will rotate 780 times per mile

And if I can fit 205/60R17s I think that is what I would do. Changing tire aspect is a lot easier and less expensive than changing gearing. Something to consider..... Jim

[Burnerboy]

I think Ronnie was talking Indicated miles traveled on the odometer... And not Miles Per Gallon......

....

Correct! Miles travel'd...........NOT........... Miles per gallon

Ronnie

[trikeman]

👍🏼

[cScjhb]

I just realized the OP posted this 7 months ago. Oh well. It caused me to do a little checking and determine what I would like to do down the road...... Jim

[camplejeune]

When R/S rebuilt my 2014 rear end they supposedly replaced the gears with the same ratio.They did not. Checking the speed using a car in front of me, the driver held 55 mph, my GL1800 was showing about 50. Using a Waze app on my phone showed the same. I guess from here on out I just need to remember that 5 mph difference. Will tire diameter fix this when it comes time to replace rear tires? Thx.

[paws]

Japanese bikes are notorious for being 5-7 miles off on the speedometer. We have dealt with this on all our Hondas, our Kawasaki 1200’s, and the Suzukies we had.

There are others out there but several years ago we used a plug and play device put out by Dakota Digital to correct the speedometer on our 2008 Gold Wings. It was easy to do and we used the Tom Tom gps to set it by.

Still working today just fine and no more guessing how fast the bike is really travelling when the radar cop is spotted. Peace of mind. People we rode with thought we were spoiling for a ticket because their speedos say we are travelling around 5mph faster than they are.

[tourman]

My 2020 Roadsmith HTS1800 is spot on with my gps mph

[Burnerboy]

I think Ronnie was talking Indicated miles traveled on the odometer... And not Miles Per Gallon......

....

Correct (miles traveled)