Hello, I have 5.30-12 tires on my magic-tilt railer. I've seen pictures of other cp16's that look like there is a smaller size tire installed. I'm interested in going with a smaller size to make launching & retriving easier (even a few inches is gonna help). I'd be interested to know how small the manufacturer may have gone & also if some of you guys with the little tires have trailered over long distances at high speed with no trouble. -thanks for the input
i wouldnt go smaller. i have 8 inchers and have had no problems with bearings but im considering12s or even 13s for mine next year. hell ill trade if you want.
The Magic Tilt tandem axle trailer under my Horizon has 10 inch wheels. I figure that these wheels are doing about twice the revolutions as the 20 inch wheels on the Chevy Avalanche that is towing it. Truck's doing about 60 mph, trailer is doing the equivalent of 120+. Note that this will effect both bearing and tire wear. I can probably live with that, but I'm not at all happy with the tiny drum brakes behind each wheel. Smallest wheel that will supprt disc brakes is 13 inch, although there are two manufacturers that have smaller discs that will supposedly work with the 10 inch wheels. I bought a set of the Kodiac's and they do NOT fit the 10 inch Magic Tilt supplied wheels. Next season I plan on upgrading to 13 inch wheels and TieDown Engineering ventilated discs.
Disc brakes are a no brainer to me. Main reason is salt water and how they effect the nearly sealed drums. If you can't flush it out immediately after launch or retrievel, the salt WILL damage the brakes, guarenteed. The wide open discs will just dry off in seconds. Add better stopping power, faster cooling down, and no need to ever adjust them.
Anyone wanting to go to much smaller wheels should possibly rethink this strategy.
Yep the disc brake pads are at all times in light contact with the discs. The heat of friction keeps things dry and clean.
What actuates the pistons in the calipers? Surge or Electrical magnetics?
Don't know a thing about what fits and doesn't fit.
I have 10" dia with well greased bearings. No brakes.
skip.
Skip - Agreed that there is light contact between the pads and rotor, but there is not much heat generated. I usually find it's about 10 degrees greater than the air temperature. The open design of the rotor, especially if it's one of the ventilated versions (two surfaces separated by cooling slots) actually helps to cool things down a lot. Drums heat up fast and lose heat very slowly. That's why they tend to fade when used a lot, like downhill on a mountain grade. I've measured trailer drum hubs at well over 300 degrees F after a 5 minute rest period. Never had a disc system register over 125 after a 5 minute cool down. But the best thing is that they shed water even quicker that the heat. Salt water won't sit inside the drum causing all sort of long range problems. They're also self adjusting. How many of you actually adjust your drum brakes at least once a year?
No brakes is not an option in most states if the trailer weighs over 2,000 or 3,000 pounds, depending on the state. My 20 foot Horizon and Magic Tilt trailer come in at around 4400 pounds, which technically calls for brakes on all wheels.
They make both electrical and hydraulic versions of both systems, with one variation that even has both. The hydraulic or surge version works by allowing the master cylinder piston rod to push back when the trailer stops. The tongue has a built in slide that causes this. Most electrics use a truck mounted programmable brake controller that senses deceleration and applies voltage. I'd prefer electric, but making them waterproof is a major issue and most boat trailers wind up with surge based hydraulic brakes. I've got 5 trailers - the 3 that carry boats are surge and the 2 car haulers are electric.
After rebuilding the disk brakes on both renditions of the DS Citroen, the earlier had two pistons on one side with a floating caliper and the latter had opposing pistons on a fixed caliper, I finally figured what pulled the pads back when the brake pedal was released. It is the distortion of the "O" rings. The round cross section is pulled to an oval when the brakes are applied and the rubber tries to return to a round shape when the brakes are released. Self adjustment is accomplished when the piston actually exceeds this "ovalization". Square cross section "O" rings respond in a similar fashion.
When building our SCCA, A-Sports Racer, an A-H 100~6, into a fire breathing Ford 289 HiPo with T-10 the rotors were fitted with front caliper Kelsey-Hayes four puck units with Mintex pads...the back calipers were Kelsey-Hayes two puck units with a proportioning valve and Mintex pads. All flexible brake lines were Aeroquip so no squish in the pedal. Raced on a new set of pads, practiced on the old race pads, new for the next race. Ed Pink built the 9 inch pumpkin and it needed the half shafts out of a Corvair to survive to twisty efforts. The moment of torque and the moment of bend.
So much fun...skip. Come to think of it our single axle race car trailer never had brakes either.
Whitecap - Having recently brought my newly acquired CP16 down from Groton, CT to Levittown, PA (~ 200 miles) and two round trips to Barnegat Bay (Bayville, NJ - ~120 miles); I (knock wood) have not had any problems with my 8" wheels. Of course they do look rather small and spin like the devil at highway speeds, but seem to be just fine for 16 footers which weigh about 1200 lbs. plus gear and trailer. I would think that Hutchins and Magic-Tilt knew what they were doing when they specified 8" wheels for the CP16.
Marty K.
Marty -
8 inch wheels would work, but just note that the bearings and tires will probably wear out a lot faster. And you may have to keep the speed down a drop as well - they could overheat at 60+ mph. Most of the heat comes from the tire distorting a drop as the flatter contact patch moves around the tire much faster than your car or truck tires. That could be the equivalent of running the 30 inch tires on my truck at maybe 180 mph.
CaptnRon28 - I agree that at highway speeds of 60+ overheating could be an issue. I've made it a habit to pretty much stay in the right lane and hold at 55. Also, I would stop every 75 - 100 miles to check the wheel bearings... and stretch my legs! Being a sailboat sailor, I'm learning that I don't need to check my watch all the time. So, should Skip be reading this post, just how many rpm are those little 8" buggers going at 55 mph? Or 65? Scary, huh?
As previously reported, my longest trip so far has been about 200 miles with two stops to check wheel bearings. My next outing (this coming weekend) will be a bit different. The 200 mile trip was from Groton, CT to Levittown, PA. Pretty flat 99 percent of the time. My other trips down to Barnegat Bay were also flat. Sunday, I plan on sailing lake Nockamixon in Upper Bucks County, PA. The roads to Nockamixon look like a rug someone pushed up from one side. No overdrive on this trip! Probably plenty of driving in 2nd gear. We'll see.
Marty K.
" So, should Skip be reading this post, just how many rpm are those little 8" buggers going at 55 mph? Or 65? Scary, huh? "
skip here, more rpm's then the toe vehicles wheels? Sure. Scary? No not really. I figure that the tire engineers who designed the tire carcass for the weight to be handled and the rpm to be encountered at high way speeds felt that they made all the right decisions when choosing the design for that smaller rim diameter.
I believe that the answer is molded right on the side wall of the tires. Somewhere it says, " LOAD RATING AT XX LB " and that is a might more important then rpm's. Don't exceed the rating.
If you go to TIRE AMERICA on line and look~see the outer diameter of the smaller trailer tire and the outer diameter of the truck tire a comparison can be made in rpm's per mile per hour. Actually I think TIRE AMERICA has such a chart.
skip.
Just for fun, I checked the tire size chart at Discounttire.com and came up with the following -
At 55mph an 8" wheel (hub) is going about 166mph (compared to a 15" hub)
At 65mph an 8" wheel (hub) is going about 197mph (compared to a 15" hub)
But, I agree with Skip, these tires are designed for high rpm's and as long as they are kept at their proper psi and aren't overloaded, they ought to last many years. I read somewhere that the tire walls will probably wear out before the tread, so keep an eye on sidewall condition and psi.
Next time you're landing in a jumbo jet, just think of the huge weight upon contact with the tarmac and the landing speed about 160 knots or so!
Marty K.
I do not have a problem with running a smaller tire , but with a larger tire you"ll slow down the speed at witch the bearings are spinning lowering the chance of failure. And the induced drag of a smaller tire compared to a larger one. Give me a taller tire any day. Have trailer will travel!!
In my opnion, the main disadvantage of smaller tires is that they rotate maybe 2 or 3 time faster than the tow vehicles tires. That means that the flat spot touching the asphalt is also moving at 2 or 3 times the rate. This flex increases heat build-up in the tires, and heat causes most failures on the road. Other objections include the fact that you can't put disc brakes behind these tires and using drum brakes in salt water is a recipe for eventual brake failure, and the bearings are doing 2 or 3 times the job they should be doing.
That said, I expect to keep the 10 inch wheels on the MagicTilt under my Horizon. But note that I expect to never have to tow this rig more than about 10 miles at lower speeds (less that 55 mph). Anything else would get me to spring for 13 inch wheels with 4 disc brakes.
I agree these tires are designed for high RPM's. But you do have to keep them inflated. Cracked sideways is what you look for. Any cracks are bad. And the "E" load rated tires are best, but I think the "D" rated ones will work on a CP16.
I've traveled several hundred (400) miles one way on 8" and 10" (CP16), and now 12" (CP19). The keys are the right load rating, keeping speed down to around 60 (occasionally will go a little faster), inflation at max pressure and stop to check and let them cool on long trips for about 10 minutes. On hot pavement, they seem to be very warm but cool enough to leave your hand on the hubs and tires. A good time to check over everything and let your cars transmission cool down (leave the engine running).
Tires that are old or unknown age or load rating should be suspect.
After getting up to one hundred twenty thousand miles on Michlin tires on some of my 1962-71 DS Citroen automobiles and sometimes driving on tires that were more than thirty years old I find it rather upsetting to have to get new tires on my five year old Rav 4 Toyota with only 18,000 miles on it.
[Why did I drive those tires so long? Blown tires on a DS and many newer Citroens have almost no affect on stability or the directional control, even with hands-off steering regardless of speed. Has anyone seen the movie "Day of the Jackel" depicting the assasination attempt on Charles De Gaulle and his wife? In the actual event both tires on one side of the Citroen where shot out: the driver simply sped up over 60 miles per hour and drove the car out of town to the airport and to safety! The high tire milages achieved on Citroens are a result of the nitrogen gas springs of the Citroen's hydronumatic suspension adsorbing the bumps rather than the tire flexing found in cars that have steel springs. (Michlin introduced the steel radial tire on the DS Citroen; the radial on the 1948 B11 Citroen.) The DS has self correcting steering meaning that you can sit on your hands at 115 miles an hour, have a front tire blow, and mash the brakes if you like: straight line stopping.
This year the feds have mandated electronic stability control on all new cars sold in the USA. The same effect was a standard feature in the 1955 DS Citroen achieved by good design including a three point suspension with four wheels; full time 2400 lb hydraulic power even with the loss of an engine or fan belts, for a period of time; hydraulic computers; survo feed back hydraulic control valves to inform the driver and the computers of the performance of features like the brakes, steering, and suspension; center suspended front wheel; and much more. . . the first car with an effective antilock brake system and the first high volumn car with disk brakes, for example.] Sorry, I will get off my soap box. My sales pitch last 2 1/2 hours, front bumper to the back bumper.
The tire industry has recently played a dirty trick on us consumers. If you read the fine print you will find a recommendation to buy new tires after 6 years, regardless of milage. The reason why? Tire manufactures, including Michlen and all the other brands they now own, are using an exterior rubber compound that weathers rapidly.
My Rav 4 SUV (Stupid Utility Vehicle) began wandering all over the road this year. A quick inspection found circumferential cracks in the rubber between the treads, plenty of tread left, and flex cracks in the side walls. Currently, the tire industry is using rubber compounds that begin failing after 6 years, to increase business. It is no longer a wise decision to buy high milage car tires if you are not going to wear them out in 6 years or less.
I have no information on trailer tires. I would keep the old one with good tread for a while longer until someone checks out the posted life span of new trailer tires. Hopefully the tire industry has not screwed them up as well.
[Unless you have a safe car (very doubtful) like the old 1955 DS Citroen, which was recognized in 2005 as the safest automobile ever, don't keep your recent tires longer than 6 years.]
Dave
This summer, I made the 1100 mile trip from Newport, RI to Savannah, GA using the set-up that existed when I purchased my boat: Magic-Tilt trailer with single axle wearing 8-inch 5.70 bias tires with load rating B. This was not good as upon weighing the trailer it came out to 1700 lbs, which exceeds the rating for B tires at that size. Likely the saving grace was the fact that the tires, bearings, and hubs were new, tires fully inflated at all times, everything checked at every stop (hours and hundreds of miles apart, more concerned about bearing temp which was never too hot to the touch), and speed kept to 60 mph or lower. Regardless of my luck, I immediately replaced those tires with C rated tires. However, these now require a fairly high psi (75) to keep their max rating at 910 lbs each. The B tires are rated for 715 lbs at 50 psi.
In retrospect, I was too fixated on replacing the original parts with exactly the same thing, without considering the future. I replaced the hubs with another set of 4-lugs, which then limits some of the available tire/wheel combinations that are available. 5-lug hubs seem to be more widely used, especially once you go over 10-inch wheels.
I am planning to again make the move to new hubs and wheels, likely 12-13 inch range depending on travel plans. 12 inches seems to be the smallest radials that I have located readily, and for long trips that seems like the way to go... However, bias tires may be the compromise that ends up making the economical sense (a paradox for things boat related, I know).
Your final thought was about making launch and retrieval easier. Besides wheel diameter, the tire diameter changes depending upon the section width, meaning that the same 12-inch wheels could be 20.7" in diameter for a 4.80-12 or 21.9" for a 5.30-12. Not a lot, but you said you were counting inches.
Based on my experience over the last season at different locations, other factors you may want to consider are trailer extensions which allow you to get the boat deeper without the tow vehicle getting as wet, lowering the rear of the bunks to allow easier "sliding," a plank instead of keel rollers, practice with the tilt mechanism (I still have trouble with this), and ramp choice (there are two lanes at my launch point, and their steepness varies depending on reservoir height... Low lake, I go left, deep lake, right lane works better).
-Justin
I use 8" tires, at 910 lbs each. Hauled my 16 from TX to CO with no problems. I do have problems at some ramps though, even with the 8" tires, when using my Volvo wagon Cross Country. Practically launch the rear of the car while launching the boat...get water in the spare tire well sometimes, which I can release by pulling a rubber plug I found in the pan, when I can remember to do so. While I considered modifying the trailer with an extension, I discovered I could add a hitch extension (about 12"). I have one of those hitches that can slip in and out, held in place by a pin. Adding another foot to this set up is easy enough for launching purposes (only!), and it keeps the rear of my wagon out of the water on most ramps now. The hitch extension slips into the original receiver, between that and the original shaft with the ball.
I thought about 12' tires for travel purposes, but with my current vehicle, simply decided a larger wheel/tire would only add to the launch problem.
BTW, I've also noticed that different brands of the same tire/size can vary by over an inch in diameter, which is a lot on an 8" tire!
Jett
" Next time you're landing in a jumbo jet, just think of the huge weight upon contact with the tarmac and the landing speed about 160 knots or so! "
Actually the most ware on aeroplane tieres occurs not at landing with great speed but rather going slowly and turning, it's the turning that scrubs off the thread.
I fellow at the aeroport I work at had six tires replaced on his twin engine 8 passenger jet for a mear $14,700. That's high dollar rubber!
Everyone tells me my e~mail was 'hacked' Bossman said change pass word. Hope that is all it takes.
skip.
I use 8" tires, at 910 lbs each. Hauled my 16 from TX to CO with no problems. I do have problems at some ramps though, even with the 8" tires, when using my Volvo wagon Cross Country. Practically launch the rear of the car while launching the boat...get water in the spare tire well sometimes, which I can release by pulling a rubber plug I found in the pan, when I can remember to do so. While I considered modifying the trailer with an extension, I discovered I could add a hitch extension (about 12"). I have one of those hitches that can slip in and out, held in place by a pin. Adding another foot to this set up is easy enough for launching purposes (only!), and it keeps the rear of my wagon out of the water on most ramps now. The hitch extension slips into the original receiver, between that and the original shaft with the ball.
Ah, another Volvo wagon. What are you waiting for Bob23? Seriously, where are 12" extensions available? That's a terrific solution. I really don't like dunking my Volvos tush in the drink. I try to stop just as the exhaust starts blowing bubbles, no deeper! Also, having the rear wheels go swimming can't be good for the "hand brake" which are just little drum brakes inside the hub.
Skip - just trying to be funny about the jumbo jet landing... I don't know anything about flying!
Marty K.
Jett
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