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Proper size for trailer wheels?

Started by shazam, October 25, 2013, 09:27:55 AM

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shazam

I'm concerned about the small size of my CP 16's trailer.  Presently they are 4.80/4.00-8's.
I have confidence that they're ok for short distances...but, what about long distance?  I expect to trailer my CP for events & just cruising for distances up to 1,000 miles.  Should I replace then to a larger size?
What sizes do you have?
shazam
s/v Morning Calm
CP 16 # 1002

skip1930

It's not the diameter of the rim and tire that's important.
It's the weight carrying ability of the tire carcass, rubber, and construction that determines the suitability of the tire.
Read the ratings on the sidewall of the tires.

Add up the weights. Boat, stuff inside, trailer, add a bit more for the 'wife and kids' and S.W.A.G. up the total weight
divide that weight by two for each side and see what the numbers say.

About tires. 'Tall tires' have long narrow foot prints while 'Fat tires' have short wide foot prints.
Interestingly both tires have the equal foot prints in square inches of rubber on the road.

But if taller tires make you feel better, check the weight load limits for the replacement wheels and tires and enjoy the ride.

skip.

kickingbug1

   i went with 570-12s on my 16 trailer. they are c rated to like 1000lbs. the boat trailers just fine and launching is not an issue plus they look better. you just have to move the fender brackets up and drill new holes in the trailer frame.
oday 14 daysailor, chrysler musketeer cat, chrysler mutineer, com-pac 16-1 "kicknbug" renamed "audrey j", catalina capri 18 "audrey j"

skip1930

#3
Can these ten inch rims be fitted with ten inch tires that carry an extra 1000 lb?
Don't know. Then what about the spindles and bearing sizes?

skip.

Salty19

Here's my opinion, barely worth $.02

First, I agree with skip.  It's not the size of the tires, it's the load rating it can handle.

For around town/short distance/low speeds, any tire rated C or better should be fine.  I would try to get load D or E ratings if possible.  Don't let a tire shop tell you they don't exist...they do, just harder to find. The extra load rating is useful on bumpy roads as the loads will go way up when bouncing over potholes.  Also to have the ability to stuff the boat full of stuff is nice, and using a load C you'll be somewhat borderline doing so (depends on the weight of your stuff).

For longer distances, I prefer taller tires as there will be less heat generated in the bearings and tires.  Imagine how fast those little 8" tires spin at 60mph...now imagine how much slower they will spin when the tire circumference is increased.  Also for towing longer distances, inflate to maximum, bring your spare/jack/tireiron and stop to check on things at least every hour (specifically heat build-up in the tires and bearings).  I stop regularly to let things cool a bit and inspect heat, tie down straps, hitch, etc, letting the engine run to circulate and cool the automatic transmission fluid.  I believe this is a huge step towards maximizing transmission life. But I digress.

The only real issue beyond clearance for the fenders (which can be adjusted per Kicknbugs' comment to a degree) is height on the trailer.  Taller tires will make you back a little further in the water.  No much, but if you're already blowing bubbles in your exhaust pipe to retrieve, this could be an issue. Also your center of gravity will be a tad higher.  Important only in emergency manuevering should some knucklehead cut you off, and to what extent, I don't know. Probably of no significant consequence-it's not a sports car on a race track.

So let's see...1100lb boat+450 trailer+ 50lb outboard+ 14lbs gas+40lb cooler+50lbs misc gear (sails, anchor,chain, clothes, tools, etc)=1704LBS or 852lbs/wheel. Tongue weight should be around 175lbs, so 1,529lbs on the trailer tires (764lbs each). Load C's are in the low to mid 900lbs rating, so not a lot of cushion-but enough. Add a battery and a bunch of camping gear...could be cutting it close with load C's, but you would have to really add a stuff..  Also when cornering, more load is created on the outer tire, so some add'l cushion is wise.  However on the CP19's with the same single axle setup, you can see how load C's will get you  trouble. Just the boat weight will exceed thier limits, not even taking into acount the trailer and stuff aboard (thus Load E's are needed for CP19's for small tires).

BTW, my old 10" tires were Secura brand...avoid at all costs, they failed prematruely for me (all three!)
"Island Time" 1998 Com-pac 19XL # 603

shazam

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Thanks all..............
shazam

Citroen/Dave

#6
My local trailer shop stop selling "Shield" brand tires (made in China) after so many failures.  They would not even give away the remaining stock for spare tires.
'87 ComPac 16/2  "Keep 'er Wet" renamed "Slow Dancing"