Wheel selection

[GRUMPYBAGDER]

I see most trailers on here running fairly large steel wheels, however most of the smaller trailers and suspension units here in the UK run 8 or 10" wheels.
What I would like to do is run matching alloys to my MG (70's cosmic rims)
Whilst I can get a matching style in 10, 12 or 13" they will almost certainly be a lot wider and that brings me to my problem.
Will the additional rolling resistance be of any great difference?.
Do I need to be careful when changing the unsprung mass of trailer wheels?.
Whilst it would undoubtedly look better, is it worth the hastle?
These are the units,

These are the standard wheels,


These are what I'd like to use

I realise I may need to space the untis away from the body or even alter the chassis but as I haven't yet started the build it shouldn't be a big deal.
Cheers. Mark.

[aggie79]

I wouldn't worry about rolling resistance. I have some fairly tall and wide tires on my teardrop.

For convenience, I would use the same wheel/tire combination as the tow vehicle. You need to be careful about torsion arm clearance, if your auto wheel has more backspace than the trailer wheel.

Good luck,
Tom

[Dale M.]

Main concerns would be wheel "back space" and diameter, whether it will clear "torsion arm" when bolted up to hub flange.... Also the issue may be "bolt circle" of lugs.... IF you can find hub with matching bolt circle to desired wheel, you can't you can probably have hubs drilled and studs moved to match desired wheel pattern...

Dale

[GRUMPYBAGDER]

Cheers guys, Fortunately the trailer hubs run the same PCD as the car
(4 x 4") so that won't be a problem, I just didn't want to plan for 12 or 13" alloys then end up with 8" bearing killers instead.
I'll see if I can pick some up in different sizes (they're quite common and cheap on Ebay), then try them on a unit.

[angib]

There is no reason not to fit larger wheels. They may increase aero drag a bit, but I bet you would be hard-pressed to measure it.

Two things you do have to watch out for is:
- do the alloys have a big enough hole in the middle to take the hub of the trailer suspension - lots don't;
- do the alloys have a deep offset so that the suspension unit will need to be mounted further out, in order not to have the tyres rubbing the trailer sidewalls.

[GRUMPYBAGDER]

The hub diameter is some thing I'll have to check before building however the wheels are after market and there's a tapered centre hole (probably intended for a spigot ring) as they were designed to fit many different cars of the same PCD.
The holes for the wheel studs are steel and the hole for the hub is quite large.
I guess like most of these things it's a case of trial and error.
What's the general feeling about the use of wheel spacers on tears?.
Cheers, Mark.

[dh]

With no real numbers other than diameter to go by, I can't yay or nay. Just based on observations from the pics, I can tell you this. 1, The cosmic's appear to have a large backspace, which means the rim may or may not interfere with the torsion arm. 2, From the pic posted, the center hole looks too small to accept a trailer hub. Thie can be machined larger if needed. 3, Those are some good looking rims.

[GRUMPYBAGDER]

Thanks to all for the reply's so far, just to clear a few things up for clarity,
the wheel centre makes the hole look smaller than it is and is also tapered to the front so it's even bigger again at the mounting face.
They do have quite a deep spacing 3 3/4" IIRC how ever I think they will cover the arm just leaving the body work to clear.
If my plan comes through then they will be in internal wheel wells to be built after the body so I can make them to suit.
I realised after a few projects that there's no substitute for offering a part into place, You inevitably don't measure the one thing that interferes with your plan.
These wheels are only available second hand now so buying a few and trying them won't cost anything as they'll easily re sell.
My bigest concern was if the trailer units wouldn't take a heavier wheel (greater unsprung mass) or that the wider tyre would sap power from the tow vehicle.
I do however retain the right to do a total u turn and completely change my mind