I have a 2004 22' on a tandem axle King Trailer (KBT4000B2), both purchased direct from the factory. The trailer is the second trailer under the boat, the first being swapped out by King when the boat was at the factory a few weeks after purchase to have the engine mountings adjusted. The King rep said the trailer "was not right for the boat". I could not tell the difference between the two trailers.
When driving over highway sections which have been trashed by semis, I have noticed my truck (04 Tundra) and trailer bounce/hop/vibrate so much I have to slow to 40-45 MPH and recently almost lost an engine cowling due to it popping off the engine during transit over that section of I-5 south of Federal Way (locals know what I'm talking about). Thinking there might be a problem with weight distribution of the boat on the trailer, I took my rig to the local scales (Cadman, one of the largest suppliers of sand and gravel in the Seattle area, digital scale) and weighed each axle. The results were interesting and very disconcerting.
Note the trailer sits perfectly level when it is attached to the truck.
Problem #1: the weight of the boat is not distributed evenly over both axles; the main load lies forward of the front axle. The front axle carries 860# more than the rear, ie, 43% more than the rear axle. (Note tere is nothing heavy or out of the usual in the forward section of the boat. The cuddy is essentially empty and I only use 20' of 5/16 chain on my rode.) The GM at King says this is "no big deal" as each axle is rated for 3500# and to rotate the front and rear tires often as the fronts will wear out sooner than the rears. I'm not so sure this is optimal. He also suggested raising the hitch to transfer some weight to the rear axle. I may try this although: a) this will make the trailer unlevel (and I have always heard this is a no-no) and b) this may decrease tongue weight below the King-recommended 5-7% of total trailer weight. The current tongue weight is 6.9% of the total boat/trailer weight. Bottom line: the boat is not set up correctly on the trailer and never has been. This is a problem I will have to fix - probably by moving the axles around on the trailer - at my expense.
Problem #2: the weight of the boat exceeds the GVWR and rated carrying capacity of the trailer by 3% and 3.5% respectively. Trailer loads should NEVER exceed about 85% of GVWR and load carrying capacity. My set up is about 18% over spec. This is a very serious problem and one which could result in loss of life or limb. The GM at King denies any responsibility here, saying they sell trailers to C-Dory who does with them as they see fit. The King GM suggests that by switching out the tires on my trailer (to load rating C from B) and swapping the winch for a higher capacity, the trailer will actually have a higher GVWR - about 5640#. Unfortunately this would still not give me the 85% cushion. I will probably need to go to load range D tires. The trailer frame, according to him has a GVWR of 7000#. A set of 5 new tires for the trailer will cost at least $450+installation. My boat , with a full, ordinary load (I carry nothing unusual) weighs 4140#. Bottom line: the trailer is too small for the boat and not fitted to the boat. I will have to correct this problem at my expense.
Key learnings:
1. Folks often ask about what to look for when checking out their new C-Dorys. Add to the list: run a weight check (see below) and get in touch with the factory if the boat (fully loaded or as calculated) exceeds 85% of trailer GVWR (the GVWR is stamped on the trailer). I also suggest you either: a) have the factory/dealer provide you with tongue and axle weights upon delivery or b) have the factory/dealer write on your sales receipt that the boat, with an ordinary complement of fuel, water and gear, is properly positioned on the trailer and will not exceed 85% of the trailer's GVWR and carrying capacity. New owners should also drive their rigs over "bumpy" highway sections to check for uneven weight distribution.
2. For folks who have boats on trailers, consider running them across a reputable set of scales. I've seen posts here that question the accuracy of large scales. Call ahead and find out - every scale has a accuracy rating. The ones I used are accurate to with 20 pounds and are inspected twice a year.
Calculating weights is easy. The following presumes the scale you are using is long enough to accomidate the towing vehicle and boat (and not just one axle at a time). Hook up the boat to the vehicle. Drive the first vehicle axle onto the scale and get the weight ("VBT1" for Vehicle, Boat and Trailer, axle 1). Drive the second vehicle axle onto the scale and get the weight (VBT2). Drive the first trailer axle onto the scale and get that weight (VBT3). Drive the fourth axle on the trailer (if so equipped) onto the scale and get the weight (VBT4). This last weight is the total weight of the vehicle, boat, trailer. Drive off the scale and disconnect the boat. Drive the vehicle onto the scale and get both axle weights (V1 and V2)
Total V1 and V2. This is the weight of your vehicle ("V").
Subtract V from VBT to get the weight of the boat and trailer (BT).
Subtract the weight of the trailer ("T" - stamped on the trailer or calculated by substracting trailer carrying capacity from GVWR) from BT to get the weight of your boat ("B"). Add to B any ordinary trailering load not present on the boat like gas (6.5 pounds per gallon) and water (8.3 pounds per gallon), beer (dunno weight per gallon but it doesn't change when ingested).
Subtract V from the weight of the second axle weighed with the boat (VBT2) to get tongue weight.
Substract VBT3 from VBT2 to get the weight load on axle 3.
Substract VBT4 from VBT3 to get the load on axle #4.
Consider making changes (eg, buying higher load range tires) if you find problems. Blow outs can be a real safety issue.
Calculating the main load point (center of mass) of the boat and trailer relative to the axle positions is more difficult. I had a PhD calculate mine. Probably any college engineering student could do the same.
Sorry for the long post. Hope it helps.
When driving over highway sections which have been trashed by semis, I have noticed my truck (04 Tundra) and trailer bounce/hop/vibrate so much I have to slow to 40-45 MPH and recently almost lost an engine cowling due to it popping off the engine during transit over that section of I-5 south of Federal Way (locals know what I'm talking about). Thinking there might be a problem with weight distribution of the boat on the trailer, I took my rig to the local scales (Cadman, one of the largest suppliers of sand and gravel in the Seattle area, digital scale) and weighed each axle. The results were interesting and very disconcerting.
Note the trailer sits perfectly level when it is attached to the truck.
Problem #1: the weight of the boat is not distributed evenly over both axles; the main load lies forward of the front axle. The front axle carries 860# more than the rear, ie, 43% more than the rear axle. (Note tere is nothing heavy or out of the usual in the forward section of the boat. The cuddy is essentially empty and I only use 20' of 5/16 chain on my rode.) The GM at King says this is "no big deal" as each axle is rated for 3500# and to rotate the front and rear tires often as the fronts will wear out sooner than the rears. I'm not so sure this is optimal. He also suggested raising the hitch to transfer some weight to the rear axle. I may try this although: a) this will make the trailer unlevel (and I have always heard this is a no-no) and b) this may decrease tongue weight below the King-recommended 5-7% of total trailer weight. The current tongue weight is 6.9% of the total boat/trailer weight. Bottom line: the boat is not set up correctly on the trailer and never has been. This is a problem I will have to fix - probably by moving the axles around on the trailer - at my expense.
Problem #2: the weight of the boat exceeds the GVWR and rated carrying capacity of the trailer by 3% and 3.5% respectively. Trailer loads should NEVER exceed about 85% of GVWR and load carrying capacity. My set up is about 18% over spec. This is a very serious problem and one which could result in loss of life or limb. The GM at King denies any responsibility here, saying they sell trailers to C-Dory who does with them as they see fit. The King GM suggests that by switching out the tires on my trailer (to load rating C from B) and swapping the winch for a higher capacity, the trailer will actually have a higher GVWR - about 5640#. Unfortunately this would still not give me the 85% cushion. I will probably need to go to load range D tires. The trailer frame, according to him has a GVWR of 7000#. A set of 5 new tires for the trailer will cost at least $450+installation. My boat , with a full, ordinary load (I carry nothing unusual) weighs 4140#. Bottom line: the trailer is too small for the boat and not fitted to the boat. I will have to correct this problem at my expense.
Key learnings:
1. Folks often ask about what to look for when checking out their new C-Dorys. Add to the list: run a weight check (see below) and get in touch with the factory if the boat (fully loaded or as calculated) exceeds 85% of trailer GVWR (the GVWR is stamped on the trailer). I also suggest you either: a) have the factory/dealer provide you with tongue and axle weights upon delivery or b) have the factory/dealer write on your sales receipt that the boat, with an ordinary complement of fuel, water and gear, is properly positioned on the trailer and will not exceed 85% of the trailer's GVWR and carrying capacity. New owners should also drive their rigs over "bumpy" highway sections to check for uneven weight distribution.
2. For folks who have boats on trailers, consider running them across a reputable set of scales. I've seen posts here that question the accuracy of large scales. Call ahead and find out - every scale has a accuracy rating. The ones I used are accurate to with 20 pounds and are inspected twice a year.
Calculating weights is easy. The following presumes the scale you are using is long enough to accomidate the towing vehicle and boat (and not just one axle at a time). Hook up the boat to the vehicle. Drive the first vehicle axle onto the scale and get the weight ("VBT1" for Vehicle, Boat and Trailer, axle 1). Drive the second vehicle axle onto the scale and get the weight (VBT2). Drive the first trailer axle onto the scale and get that weight (VBT3). Drive the fourth axle on the trailer (if so equipped) onto the scale and get the weight (VBT4). This last weight is the total weight of the vehicle, boat, trailer. Drive off the scale and disconnect the boat. Drive the vehicle onto the scale and get both axle weights (V1 and V2)
Total V1 and V2. This is the weight of your vehicle ("V").
Subtract V from VBT to get the weight of the boat and trailer (BT).
Subtract the weight of the trailer ("T" - stamped on the trailer or calculated by substracting trailer carrying capacity from GVWR) from BT to get the weight of your boat ("B"). Add to B any ordinary trailering load not present on the boat like gas (6.5 pounds per gallon) and water (8.3 pounds per gallon), beer (dunno weight per gallon but it doesn't change when ingested).
Subtract V from the weight of the second axle weighed with the boat (VBT2) to get tongue weight.
Substract VBT3 from VBT2 to get the weight load on axle 3.
Substract VBT4 from VBT3 to get the load on axle #4.
Consider making changes (eg, buying higher load range tires) if you find problems. Blow outs can be a real safety issue.
Calculating the main load point (center of mass) of the boat and trailer relative to the axle positions is more difficult. I had a PhD calculate mine. Probably any college engineering student could do the same.
Sorry for the long post. Hope it helps.