15 inch spare to replace 14 inch??

[Husker-Q]

I have 14-inch wheels on boat - need a spare and have an opportunity to get a free one but it is 15-inch. For short term use situations - would that be a problem? (assuming fender clearance). Would that cause vehicle wander or similar?

 

[batman99]

Re: 15 inch spare to replace 14 inch??

For Trailer "tire sparing", its all about risk and impact. Risk of needing to use a spare? And if needing to use a spare, what is the negative impact?

I've been pulling trailers for 25+ years and never needed to use the trailer's spare tire. But, I always ensure I have a spare, wrench and jack - just in case I need it. Without a spare, I'd evaluate the negative impact without a spare. For example, trailing on Sunday and all local tire stores / auto shops are closed. Thus, I'd have to leave my trailer at side of road - until I get a tire replacement on Monday. If store is open, how far away is the tire store / auto shop - to fix existing flat tire? After all the + / - comparisons are added up, I always carry a spare with wrench and jack. And its spare is matching its other normal usage tire size and lettering. re: . ST205/75r14

If using different size spare, the trailer stance won't be level. The low side (due to natural gravity) will endure more load weight. And since axle isn't level, its lower side wheel bearings will be over stressed as well. Thus, hurting its spindle, bearings / races and seals. And, trailer brakes (if you have them) will behave differently as well. re: Pull to one side - because wheel's aren't the exact same physical size. With all this, I'd recommending using same size spare.

However... Since the 15" tire is for free, I'd take it "for free". Then, try to sell or trade this 15" tire for a proper matching 14" tires. Especially if this 15" tire is in great shape (and its under 6 years of its creation date).

Note: For more info about tire age and "under 6 years" warning, surf: http://www.youtube.com/watch?v=pxlsKPCzjyw This 6 year limit applies to RV, utility and boat trailer tires as well....

Hope this helps...

 

[ondarvr]

Re: 15 inch spare to replace 14 inch??

As a spare needed to just get you home or finish out the day it will work fine, you do need to ensure the bolt pattern is the same though. Make sure it fits under the fender with no rubbing too.

 

[NYBo]

Re: 15 inch spare to replace 14 inch??

The rim size isn't what's relevant, it's the outside diameter and width of the tire itself. You want the sizes to be very close to each other, within perhaps 10%.

 

[dan t.]

Re: 15 inch spare to replace 14 inch??

Any spare is better than no spare, grab it.

 

[jestor68]

Re: 15 inch spare to replace 14 inch??

i have 14-inch wheels on boat

what?

 

[Brewman61]

Re: 15 inch spare to replace 14 inch??

I have 14-inch wheels on boat

Interesting. I have no wheels on my boat. Unless you count my 14.25" prop. as a wheel, some folk refer to boat props as wheels.

- need a spare

A good idea for your trailer tires and you boat's prop.

and have an opportunity to get a free one but it is 15-inch.

Full tire and wheel assembly? Make sure the bolt pattern matches. Not sure if they differ between 14" and 15" or not.

For short term use situations - would that be a problem? (assuming fender clearance). Would that cause vehicle wander or similar?

Define short term. Do you plan only to get flat tires close to home? Murphy's law dictates that you'll likely get a flat under the worst possible circumstances. If the spare fits and doesn't rub the fender, you'll probably "get away" with it, but it's not something I personally would be comfortable with.
Take the free spare, put it on Craigslist, and use the money towards a correctly sized spare. That was suggested earlier, and it's pretty good idea IMHO.

 

[doyall]

Re: 15 inch spare to replace 14 inch??

Any spare is better than no spare, grab it.

I suppose I subscribe to this philosophy as well as I carry a mis-matched spare smaller than the trailer tires. If forced to use it I will be strictly in limp-home mode. Fortunately I live relatively close to the ramp and can make it home without traveling at highway speeds.

 

[jayhanig]

Re: 15 inch spare to replace 14 inch??

When I first bought my boat it came with a 13" and a 14" tire; one radial and one bias ply; one on a galvanized rim and one on a painted rim. It towed home OK but one of the first things I did was buy a pair of 13" bias ply tires on galvanized rims. I took the original 13" bias ply tire on a painted rim and made it my spare. Seemed the cheapest and quickest way to fix my problem.

 

[kenmyfam]

Re: 15 inch spare to replace 14 inch??

You have a lot of time, work, $$$$ and enjoyment tied to your boat. For what a correct spare will cost you and the peace of mind that goes with it. Get the proper wheel and tire for your outfit.
It's like buying a pair of shoes and one of them is 2 sizes bigger than the other. You can still wear them but they are sure not comfortable, that is unless you have different size feet to begin with

Just my thoughts though.

 

[T_Herrod]

Re: 15 inch spare to replace 14 inch??

Mixing a 14" and a 15" wheel on a trailer is not something i would NOT recommend. I don't even like mixing bias ply and radials. Not sure if the bolt pattern will be the same. If this is something you must do the there are 2 things i would suggest. The first is pray that you never have to put the over sized tire on. And if you ever have to do use the spare drive very slowly to the nearest repair shop and get the correct sized tire repaired.

 

[matt167]

Re: 15 inch spare to replace 14 inch??

You could figure out the tire size to get it close to the diamater of the 14" trailer wheels, but you still would need a new tire, and they are expensive. A better alternative is to find the diamater, and then get a complete trailer tire/rim from TSC that matches close or exact size on a 14" rim. In the event you need to use it, you know it will get you where you need to be. Cost should be less than $100 for the tire and rim package.

 

[ondarvr]

Re: 15 inch spare to replace 14 inch??

Come on people, this isn't a Porsche that is going to be raced, or an AWD vehicle that needs to have identical tires that even need to have the same amount of tread wear. This is a spare tire for trailer that just needs to get him home (if its ever used), it will not veer directly off the road the minute he gets over 5mph and burst into a ball of flames.

While I wouldn't recommend running a tire of a different size in a normal situation, I would much rather he use a "good" different size tire than the old, bald, cracked and underinflated stuff I see in every boat launch parking lot...and that's on the tow vehicles. The difference in ride height of the a 14" and 15" is 1/2 an inch (assuming they are similar ratios), lets double that and say its 1", it will never be noticed when it's being towed.

 

[UncleWillie]

Re: 15 inch spare to replace 14 inch??

I have 14-inch wheels on boat - need a spare and have an opportunity to get a free one but it is 15-inch. For short term use situations - would that be a problem? (assuming fender clearance). Would that cause vehicle wander or similar?

This is a spare tire for trailer that just needs to get him home, ...it will not veer directly off the road...and burst into a ball of flames. ...The difference in ride height of the a 14" and 15" is 1/2 an inch... it will never be noticed when it's being towed.

OP; It is easy to answer your own question.

Put the Tire on the trailer NOW, while you do not need it.
Go and drive around and decide for yourself if you would be willing to use the mis-matched tire in a pinch!
If so, Go forth and prosper. If Not, Replace the thing!