Dyna/Sportster center of gravity
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Tourer
Joined: Feb 2015
Posts: 340
Likes: 21
From: NashVegas
Just thought it was time to update this thread.
I bought the aforementioned 5x8 trailer, decked it with 3/4 treated plywood, installed 2 locking wheel chocks for the Dyna and Sportster. I added 2 large eye bolts in the front center for cargo straps and 2 small d-rings in the rear (because they will lie flat on the floor for loading).
I got the centers of gravity pretty much spot on. With both bikes loaded, the tail lights sit about 2 inches from the ramp (in travel position). With both bikes loaded, the tongue weight is such that I can easily lift the front of the trailer by hand, and yet there is enough tongue weight that it rides securely.
After letting the wood fully cure, I applied 3 coats of roll on truck bed liner coating.
Here's a pic.
I bought the aforementioned 5x8 trailer, decked it with 3/4 treated plywood, installed 2 locking wheel chocks for the Dyna and Sportster. I added 2 large eye bolts in the front center for cargo straps and 2 small d-rings in the rear (because they will lie flat on the floor for loading).
I got the centers of gravity pretty much spot on. With both bikes loaded, the tail lights sit about 2 inches from the ramp (in travel position). With both bikes loaded, the tongue weight is such that I can easily lift the front of the trailer by hand, and yet there is enough tongue weight that it rides securely.
After letting the wood fully cure, I applied 3 coats of roll on truck bed liner coating.
Here's a pic.
Road Captain
Joined: Feb 2013
Posts: 652
Likes: 7
From: Maui, Hawaii
Ride Safe - Ride Smart
"He Who Lives In Joy Does His Creator's Will".
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Seasoned HDF Member
Joined: Mar 2010
Posts: 38,414
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From: Honah Lee
Best balance for mine on the jack is to put the right lift plate under the timer cover. I find it interesting that no where in the owner or service manual is mentioned where the center of gravity is. I guess that they also expect you to lift it from the right missionary side.?
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Tourer
Joined: Feb 2015
Posts: 340
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From: NashVegas
I recall that the rule of thumb is at least 10% of the total trailer weight should be on the hitch for a safe tow, no side-to-side wandering of the trailer under tow. Easiest way to verify would be to set the end of the tow bar on a household scale before hooking it to the trailer hitch.
Ride Safe - Ride Smart
Ride Safe - Ride Smart
Extreme HDF Member
Joined: Dec 2007
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From: Illinois
I have a rough way of finding the fore and aft cg. I lift it on a floor jack. When it balances without wanting to tip either way the cg is very likely between the two lifting bars.
I have set up many trailers for towing bikes over the years. the standard is 10% of the gross weight on the hitch. Single axle 60% of the load in front of the axle. Dual axle 70% ahead of the axle. The hitch height should position the bed of the trailer parallel to the ground
All three of those done right will will result in a trailer that will not sway, porpoise and will have the least drag.
I weight cabinets, spare tires, tools and anything else to be in the trailer and distribute that weight. All needs to be factored in not just the bike.
If you have a trailer and load that approaches 3,000 lbs a load equalizing hitch should be installed. I even use it for a 6'X12' single axle. I can be in strong cross winds going down a grade with a semi passing and it will track like it was on rails.
That's the 8.5' X 20' rig that I towed for 7 years. Before that I had a 6' X 12' single axle that I towed for 7 years. I'm currently back to a 6' X 12'. For three decades prior to those trailers I pulled big boats. towing is serious business and is risky like riding a motorcycle.
I have set up many trailers for towing bikes over the years. the standard is 10% of the gross weight on the hitch. Single axle 60% of the load in front of the axle. Dual axle 70% ahead of the axle. The hitch height should position the bed of the trailer parallel to the ground
All three of those done right will will result in a trailer that will not sway, porpoise and will have the least drag.
I weight cabinets, spare tires, tools and anything else to be in the trailer and distribute that weight. All needs to be factored in not just the bike.
If you have a trailer and load that approaches 3,000 lbs a load equalizing hitch should be installed. I even use it for a 6'X12' single axle. I can be in strong cross winds going down a grade with a semi passing and it will track like it was on rails.
That's the 8.5' X 20' rig that I towed for 7 years. Before that I had a 6' X 12' single axle that I towed for 7 years. I'm currently back to a 6' X 12'. For three decades prior to those trailers I pulled big boats. towing is serious business and is risky like riding a motorcycle.
Last edited by lh4x4; May 28, 2015 at 11:58 PM.
Road Master
Joined: Dec 2012
Posts: 755
Likes: 189
From: Sartell, Minnesota
Don't over think this. Just place the rear cylinder just ahead of axle and it should be fine. You should have between 150 and 200# on the tounge depending on the trailer weight. You are better off more weight on the tongue than not enough.
Grand HDF Member
Joined: Nov 2012
Posts: 3,515
Likes: 886
From: Upstate New York
Good to see you have a trailer with the "A" frame. Here is a link to a video on tying down your bikes. Pay special attention to the tie down points and how not to compress your suspension.
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Tourer
Joined: Feb 2015
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From: NashVegas
Thanks for the link. That is an informative video. The zip ties are an excellent idea!
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