ST1100 Center of Gravity

this information should be in the owners pamphlet. but I lost mine a few years ago. I have made a cursory look into my Clymer manual and nothing in there either. does anyone know these numbers? I'm doing the preliminary design work for a DImyself utility trailer. the old one I've been working with was so poorly designed in this respect that I always feared I'd have an accident when hauling any serious weight. If I dared to go faster than 35mph. the new trailer is needed to haul the bike to my new home 1k miles away. I have two design criteria. one to be able to carry a yard of soil/bark and the other to haul the bike. I don't want to or need to build the bed any bigger than required for these loads. by necessity I have to work alone, so weighting the bike by myself is out of the question. thanking all in advance.

I only saw "gravity" mentioned once in this version of the manual. (not CG)

http://www.schallenberg.nl/website/manuals/ownersmanualst1100.pdf

I think by CG you are really asking front/rear weight distribution so you know where to position the bike so that its weighting the hitch as opposed to unweighting it, is that correct? I looked for that in the service manual and owners manual and didn't see it. If anything I'd guess its slightly front biased because of the engine. I doubt its more than 55/45 biased, probably a little more evenly distributed than that. I'd make sure the trailer bed is long enough that you can get 3/4 of the bike in front of the trailer axle, then you know your weight distribution will be biased towards the hitch. Never designed a trailer, so I don't know exactly how much load you want distributed on the hitch, but I doubt you have to calculate it precisely.

when mine blew its coolant hose under the carbs I borrowed my neighbors trailer to go back and bring the bike home. I don't think there was anything special about his trailer, and it worked fine at freeway speeds. Another issue is making sure your ramp can support the 750lb load of the ST when loading it into the trailer. Those aluminum ladder type ramps aren't all rated the same, so if you're using one of those make sure its designed for higher weight and not dirtbike type loads.

A general guideline is that the weight on the hitch should be 10-15% of the load that you are hauling.

Was thinking that c of g should be 60/40... 60% foward of the trailer Axel and 40% of the weight aft of Axel. That's rather coarse, but works pretty good. things get a bit dicey when an alternative load is thrown into the mix. ( the landscaping material) lacking the cog for the motorcycle I'll have to deal with larger margins of error(right word?) It can be done but the bed size increases with the cog uncertainty. Guess I'll have to either make it bigger so that weight can be shifted, or develop a way to weight the front and back tires and figure it our from the result. Well if things were simple the world would be a bit boaring. Thanks all who replied.and thank you sr1300r for the owners manual.

A yard of soil weights about 3000 lbs. so that will determine what kind of trailer you get.

The published (MCN) front/rear balance of the ST1300 is 45%/55% biased to the rear wheel. Honda moved the engine forward about 1.75" and down about 3/4" so the ST1100 has to have a similar F/R balance.

The center stand is pretty close to the CG front to back.

The interwebs says 9-15% of gross wt on the hitch ball for stability.
A bathroom scale would be in range. Put it at the hitch ball height or pc of pipe or something on the scale up to that height and move the bike until your around that target.

dduelin said:

The published (MCN) front/rear balance of the ST1300 is 45%/55% biased to the rear wheel. Honda moved the engine forward about 1.75" and down about 3/4" so the ST1100 has to have a similar F/R balance.

Click to expand...

surprised to hear that, perhaps the location of the fuel tank moves it more rearward. A quick search shows the 2015 FJR1300 at 52/48 front/rear, which is what I'm more used to reading, but I don't look at those specs very often.

darn good detective work, Dduelin!!!.. that works out to be 27inches forward of the rear tire contact point.( total from front to back contact points is 60") I believe these measurements are typically made with full fuel as well as empty panniers in place. fwiw- the ctr stand "heel" is 4.5" behind the cog point (when deployed). which explains why the rear wheel is lifted off the ground when up on the c.stand. thanks to all, I'm pretty well armed with enough information to enter into the designing portion of this project.