Strange question about rim size....

[gunner1]

I know it seems like an obvious "yes", but if I go from an 8" wheel to a 12" wheel does this raise the trailer four inches?

 

[KurtG]

Re: Strange question about rim size....

no, half that (2") and you loose 2" clearance on the fenders.

 

[Utahboatnut]

Re: Strange question about rim size....

I think it is more like two inches, cause your going from the center point not the overall. Bigger question might be is there enough clearance all the way around fenders/trailer frame/etc.

 

[gunner1]

Re: Strange question about rim size....

Well, the fenders need to go anyway so... I'm just trying to avoid buying a CMC power tilt and trim just to raise the motor for transport if I can increase the rim/tire size to get the extra clearance.

 

[Frank Acampora]

Re: Strange question about rim size....

Even though the tire size is defined by the rim diameter and width of the sidewall, the 5.20 X12 while wider will still be slightly higher than the 4.80 X12. So if it worksm spend the extra money for the higher load capacity 5.20 and get another 1/4 to 1/2 height.

If it is a bunk trailer, you could always raise the bunks a bit too. If you are lucky or good, you might be able to raise rollers too.

 

[fishrdan]

Re: Strange question about rim size....

Are you just trying to get the outboard's lower unit higher for trailering?

I bought a transom saver for my outboard and it raises the outboard 9"-12" while trailering the boat, also keeps the outboard from banging around on the transom while going over rough road. Cost = $20

EDIT: Just looked at your share project and those tires look tiny, yeah I would go to a bigger tire/rim size.

 

[jay_merrill]

Re: Strange question about rim size....

Don't forget that raising the height of the aboat above ground level, no matter how you accomplish that, will result in having to back the trailer deeper into the water to float your boat (pun intended! ).

Because of this, you may run into issues related to the length of the tongue on the trailer. Specifically, if backing in further causes you to have to partially submerge your rear wheels and/or exhaust, you may have to lengthen the tongue on the trailer to avoid this.

Rather than to change the trailer, my advice is to raise the motor manually if you don't have TT. It really shouldn't be that hard to do.

 

[gunner1]

Re: Strange question about rim size....

Are you just trying to get the outboard's lower unit higher for trailering?

I bought a transom saver for my outboard and it raises the outboard 9"-12" while trailering the boat, also keeps the outboard from banging around on the transom while going over rough road. Cost = $20

EDIT: Just looked at your share project and those tires look tiny, yeah I would go to a bigger tire/rim size.

I was thinking about the transom saver idea today actually. I was in Gander Mountain and they had them for $30. You're right though- those rims ARE tiny. They also require a short hub- which caused me alot of grief last year trying to replace them. Every store I bought them from ( four different stores, four different brands!) were all wrong. I finally found them at the trailer parts superstore. SO maybe a combination of the transon saver AND the larger wheels. Either way, something needs to be done before striper season starts!.

 

[fishrdan]

Re: Strange question about rim size....

something needs to be done before striper season starts!.

OH YES, you need to get ready for striper season,,,

LOL couldn't resist

I'm sending you a PM on the transom saver...

 

[gunner1]

Re: Strange question about rim size....

OH YES, you need to get ready for striper season,,,

LOL couldn't resist

I'm sending you a PM on the transom saver...

NICE STRIPER!!! Where di you catch her from? I got your PM, but you didn't include the link.

 

[kabcpapc]

Re: Strange question about rim size....

If you decide on a transom saver, try Wal-Mart. I was in there recently and was looking in the sporting goods section when I saw a Swivl-Eze Adjustable Transom Saver on clearance for $5.00! Needless to say I bought it. I think Wal-Mart is trying to reduce their marine inventory. I also got on clearance 2 battery boxes for $1.50 each and an Attwood 10" bow light for $4.00.

 

[fishrdan]

Re: Strange question about rim size....

Where di you catch her from?

Below Hoover Dam, Willow Beach

Link sent :redface:

Swivl-Eze Adjustable Transom Saver on clearance for $5.00! I think Wal-Mart is trying to reduce their marine inventory. I also got on clearance 2 battery boxes for $1.50 each and an Attwood 10" bow light for $4.00.

Hmmm, be back in a few minutes............

Seriously, thanks for the heads-up. I need a few battery boxes. The MW's in my area have been slimming own their outdoors section for the past few years. less and less selection.

 

[mhg]

Re: Strange question about rim size....

wally world around here have pulled almost everthing
from the shelves for mark down
they have restocked with atwood
everything in the boat section is now atwood

 

[jay_merrill]

Re: Strange question about rim size....

If I were a bettin' man, I'd say that your trailer did not originally come with your boat. While it looks OK from a length standpoit, it is too narrow for the hull - notice that the wheels are under the boat, not slightly outside of it.

If your are careful, you will probably be OK with this trailer for awhile, but you might want to consider replacing it with something that better fits the boat. In the mean time, try to keep the center of gravity of the boat as low as possible, and take it easy on the curves in the road.

 

[clarkbre]

Re: Strange question about rim size....

I'm suprised no one has got down to the nitty gritty and commented about the bearings. Bigger/taller wheels and tires would be a huge benefit for the ride, capacity, and bearing life. The larger diameter would slow the bearings down and give them a lot less stress. I don't know what your axle is rated for but that might be a way to beef up your trailer as well.

If you were to switch to bigger tires (4.80-12) the bearings would spin about 20% less helping with the wear and tear. Also, if you switched out to a heavier duty axle, you could always go a little wider for better stability.

I know from experience that switching from 4.80-8 to 4.80-12 makes a world of difference in how the trailer rides and tracks behind a car. I did this on my utility trailer and it's like night and day. I wouldn't even consider running 4.80-8 again.

 

[reelfishin]

Re: Strange question about rim size....

The amount of increase in height will vary by tire profile and size. It depends on what size you had, and what size you are changing to.

Larger tires pull easier and ride smoother, carry more weight, turn slower thus create less bearing heat, and larger tires also are less likely to fail at higher speeds due to overheating.

I all but consider 8" tires a thing of the past, I won't buy any new trailer with 8" tires. The way I see it, 8" wheels were used back in the day to get the boat lower and easier to launch, today's trailers do that by design, not tire size.
I sort of look at 8" wheels as being more for local use than long distance, I've had all too many of them fail at highway speeds. The smaller tires seem to be ok when new, but after a few years and some dryrot, they're no longer reliable, far more likely to fail than a full size tire.

 

[gunner1]

Re: Strange question about rim size....

The amount of increase in height will vary by tire profile and size. It depends on what size you had, and what size you are changing to.

Larger tires pull easier and ride smoother, carry more weight, turn slower thus create less bearing heat, and larger tires also are less likely to fail at higher speeds due to overheating.

I all but consider 8" tires a thing of the past, I won't buy any new trailer with 8" tires. The way I see it, 8" wheels were used back in the day to get the boat lower and easier to launch, today's trailers do that by design, not tire size.
I sort of look at 8" wheels as being more for local use than long distance, I've had all too many of them fail at highway speeds. The smaller tires seem to be ok when new, but after a few years and some dryrot, they're no longer reliable, far more likely to fail than a full size tire.

So how about switching from the new 8" wheels I bought last year and haven't seen the road yet to these tires and wheels: http://shop.easternmarine.com/index.cfm?fuseaction=catalog.prodInfo&productID=5376&categoryID=158

 

[reelfishin]

Re: Strange question about rim size....

I run 13" on all my trailers, I've never had an issue with blowouts or bearing failures and they last far longer.
Provided that they don't raise your boat too high to launch and you have fender clearance, 13" would be my choice.
Quite often a trailer built for 12" wheels will take 13" tires without any modifications but you have to test fit them to be sure.

 

[mthieme]

Re: Strange question about rim size....

I had one trailer that came with 8" tires.
I quickly replaced with with 12".
When towing at highway speed, that little 8" donut is spinning like the dickens. It might be me, but it seems every trailer I've ever seen on the side of the road had only one puny tire left on it.
A couple inches in height has not made enough difference at the ramp for any redesign.

 

[VaGent]

Re: Strange question about rim size....

Since tires & wheels are being discussed here, I'd like an opinion on the following.

I have 2 sets of "D" rated boat trailer tires of the following sizes: 20.5X8.0X10 & another set that are 175/80/13. Both are high speed rated trailer tires & wheels. When mounted on the trailer they will be 88" apart measured from the center of the treds. My maximum weight will be no more then 2500#. Which would be the most preferred tire/wheel to use generally speaking?