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wheel and tyre size

PostPosted: Sat Nov 13, 2010 3:58 am
by sleepcookiemonster
Im building a cub/modernair type trailer and i have a set of wide cub fibreglass fenders (mudguards) and was wondering what the best size wheel/tyre combo to use as i want to fill the fenders?
Thanks

PostPosted: Sat Nov 13, 2010 10:05 am
by Dale M.
I would think that is sort of a tough one.... If it were me I would try a couple if different combinations to see what I liked best and go with that and design axle and suspension to accommodate wheel/tire/fender combination...

Dale

PostPosted: Sat Nov 13, 2010 12:47 pm
by caseydog
On that style teardrop, I like a 15-inch wheel and tire. I'm thinking a 15X6 wheel with about a 215-75-15 tire.

CD

PostPosted: Sat Nov 13, 2010 1:29 pm
by GPW
OK, here's a question ... Got tiny 4 lug tires on my Mini CT ( 530-12 max load 840 lbs)... would like to upgrade to larger tires.... Ya' think I need a new axle and hubs ???

Image

PostPosted: Sat Nov 13, 2010 1:49 pm
by caseydog
GPW wrote:OK, here's a question ... Got tiny 4 lug tires on my Mini CT ( 530-12 max load 840 lbs)... would like to upgrade to larger tires.... Ya' think I need a new axle and hubs ???

Image


Nope, as long as you can find wheels with the same bolt pattern. Just watch your clearances. You may need to find a larger, but still narrow rim, to keep from rubbing on the inside.

CD

PostPosted: Sat Nov 13, 2010 2:12 pm
by GPW
CD, I noticed on one side , tire clearance is very close . some rubbing has occurred ... :o I'd hate to resort to offset rims ...

PostPosted: Sat Nov 13, 2010 2:31 pm
by angib
GPW wrote:OK, here's a question ... Got tiny 4 lug tires on my Mini CT ( 530-12 max load 840 lbs)... would like to upgrade to larger tires....

The first step you could take would be to go to Load Range C (LRC) tires* in the same 5.30-12 size as your current Load Range B (LRB) tires - that would up the load capacity per tire from 855 to 1050 pounds (by upping the max psi from 55 to 80).

The next sizes in trailer tires are:
ST175/80D13 (LRC) - 1360 pounds capacity each - 6.7" wide
ST205/75D14 (LRC) - 1760 pounds capacity each - 8.3" wide

Now that 14" tire is 3" wider than your current 5.30-12, so if you want to keep the same inside clearance to the frame (which likely is tight), it has to sit on wheels with a 1.5" outset, or on 1.5" spacers.

Assuming you use some of the increased tire capacity and combine that with a wheel that overhangs the bearing means you may get a short bearing life. Catastrophic bearing failure is unlikely if you inspect them for noise regularly, so maybe at worst you have to replace the bearings every year, which doesn't seem a disaster, as long as you are mechanically 'handy'.

* See, sometimes I can remember to write 'tire' instead of 'tyre'.

PostPosted: Sat Nov 13, 2010 4:32 pm
by GPW
Angib , Thanks , I always have some FEAR as tire pressures are increased, and although I'd assume ( :roll: ) they were made for such treatment , I can't help but wince as I inflate them ..

Don't plan on heavy hauling , just light recreational use , but I do have to solve the rubbing problem ... the tire is very close (1/2") to the frame .. as these pics demonstrate ... Perhaps a rim with a milder offset , and a simple upgrade to the LRC tires would be the easiest solution , as you suggest, and possibly the most thrifty in the long haul... less worry about the bearings and all , although it's become my habit to constantly check the hub temps. at each stop...
http://tnttt.com/album_ ... c_id=72939
http://tnttt.com/album_ ... c_id=72940
It would also appear that from the looks of the bottom and frame , I also have some painting and undercoating to do ...
Thanks Again , I now know what to look for !!! :thumbsup:

PostPosted: Sat Nov 13, 2010 8:21 pm
by doug hodder
I used a 205 75R15 Wide white under that fender. If it's too wide....you can always cut them down a bit. I did a sticky on how to narrow them up for the fit you want. Doug

PostPosted: Sat Nov 13, 2010 9:24 pm
by Dale M.
For tire rub issues, you can always have a custom wheel made that will give you a little bit more clearance by having less rear offset.... Yes I know the offset is supposed to keep bearing load equal, but by changing it only a inch or so is not going to be much of a issue and you mentioned bigger/different wheels anyway....

Dale

Re: wheel and tyre size

PostPosted: Sat Nov 13, 2010 10:46 pm
by grant whipp
The original question was:

sleepcookiemonster wrote:Im building a cub/modernair type trailer and i have a set of wide cub fibreglass fenders (mudguards) and was wondering what the best size wheel/tyre combo to use as i want to fill the fenders?
Thanks


The original fenders were sized for 16" wheels ... 15"ers will work fine with big enough tires (like Doug mentioned), but anything smaller will get lost and look way out of place. Width of wheel and tire will depend on axle chosen and ultimate hubface measurement, to see just hw much room you'll have to work with.

Good Luck, and ...

CHEERS!

Grant

PostPosted: Sun Nov 14, 2010 12:50 am
by aggie79
I'm using a pair of Grant's Mod/Cub/Kenskill fenders. My tires are P235-75R15 on 15" x 7" wheels. To me, they seem to fill out the fenders quite well.

Image

Image

Tom

PostPosted: Sun Nov 14, 2010 7:08 am
by GPW
Man , I'd LOVE to use some of Grant's streamline fenders on my mini CT ... Much COOLER than those tin can things I have ... 8)

PostPosted: Sun Nov 14, 2010 11:14 am
by Gerdo
A big goal when I was choosing tires was to go with something that I could get a replacement anywhere USA. I went with a P-series (passenger car tire) 205/75-15.

A trailer tire will carry more weight and have stiffer sidewalls but P-series tires run a lower psi and ride smoother. Our TDs aren't going to max out the capacity of a P-series tire, even most cargo trailer conversions.

PostPosted: Sun Nov 14, 2010 10:22 pm
by sleepcookiemonster
Thanks for your help all, I think i will be useing 15x7 jeep rims and 215x75x15 tyres for now, it leaves about 11/2" wall clearence