Wheels that fit (barely)

So after much experimentation and miserable fiddling I managed to find rims I like and some nice beefy wheels that fit well and look good (to me)

I went with motegi M7 17x7 rims, and the wheel I am looking at is 255/35 r 17 which ends up with almost an identical wheel diameter.

The 40mm offset of the motegi puts the outer and inner edge of the 255 exactly where I want it.

Stock ride height (ugh) i am fine. I intend to lower the '80 about 4 inches eventually and when I do, I am looking at putting some low profile flanges on it (probably doing metal cutouts from a donor vehicle - but which vehicle isn't a certainty yet)

At the very extreme turn radius I may have some light contact with the torsion bar in front. (that is the torsion bar right?) so that might need to be massaged a little.

The bumpstop in the back is going to get hammered flat for now, and later I may modify it more cleanly. The back clearance is great, except for that minor issue.

My girlfriend complained because she said that those wheels made the car look too tough, and that she liked the quaint look it had. I said "I never intended to drive quaint." =)

I haven't found many tires that size. I am looking for one Sumitomo 255/35R17 so I can test fit it.

I test fit with a 255/50

I'll put up photos when I am done - since this would have been useful to me if someone else had done it.

Well, looks like I might have to go with 255/*40*/17s - since 35's seem pretty scarce. slightly larger tire. Don't think that is going to matter significantly.

Have you weighed your wheel/tire combination yet?

A little bit taller sidewall will give you a little more cushion... although it doesn't sound like ride quality is a priority. Are you doing anything to reduce steering effort?

Quote: "At the very extreme turn radius I may have some light contact with the torsion bar in front."

Sounds like you mean "sway bar" (aka anti-roll bar). You may be able to modify it as Graham Creswick did here: http://www.britishv8.org/MG/GrahamCreswick/GrahamCreswick-N.jpg (with a big press). Some people use thicker spacers between frame and sway bar too. I think shortening the links is required if you do that...

no, haven't weighed it yet. Haven't found the right tire yet, sadly.

I do mean sway bar, and it starts with a 255 section width tire. if I go to a 245 I won't have a problem

I don't expect to have a steering effort issue. I've driven manual steering all my life.

I like the feel of the road in my hands.

Trust me, with a 35 section tire, you're going to feel it in more than your hands!

Looks like it's moot. There are no 255/35/17 wheels available

I am going to have t ogo 245/40/17 - which is better anyhow because I won't have to mod the sway bar

What is the widest tire you can put on 7" rims

In my case, the widest tire I can fit is a 255. any wider will hit the metal of the wheelwell and the sway bar on a turn.

I don't count the bumpstop because that is not cooperating with me anyhow and will get hammered down.

mgbv8dbw Wrote:

Nox, a couple of things to think about...

i think the widest tire that will fit on a 7" rim is a 225. Each tire manufacturer specifies the rim widths that will work with each tire to ensure the bead seats properly. You may get lucky & find a 245 that'll go on a 7" rim, but be sure to check before ordering if you're ordering on-line. If you're buying from a local tire shop they'll likely verify rim size for the reason Derek noted above.

Also, you might be better off with the 225's anyway. If the 255's were going to be tight even after massaging the bump stop bulge, you'd probably still get rubbing unless you added a panhard rod to keep the rear end from moving side to side [which it does some with spirited driving & curves]. Also massaging the bump stop bulge with a hammer will be harder than it looks. When you pull the rubber bump stop off, you'll see there's a rather stout peg that it mounts on that's welded to the frame rail. The diameter of that peg + the weld that goes all the way around are why the bulge is there. If you go at it with a hammer, you'll likely end up with the bump stop bent at an angle which will get worse as the suspension hits it. So 225's *may* save you some work & they're only about 1.25" narrower than the 255's (25.4mm to an inch).

Good luck & keep us posted on what you decide -- pics too when you get the tires & have them mounted.

Ah. so.

I haven't dismantled the stops to see what I have going on in there. The best plan I'd heard was to cut a inverse V in the stop and then close the joint and weld that shut.

I need to look at it and decide.

On the other hand, 225/40 R17s are easy as hell to find. In fact I think I saw a whole set of them at this salvage tire place and they looked like they still had nubs on them for 30 bucks each mounted. I might put those on and drive it a bit and see what I think.

I still need to take off some bumpstop. I didn't think about panhard.

I am not terribly fond of the MG's rear axle and suspension.

For what it's worth, when I had 195/60x14" tires on more than standard offset (i.e. further inboard), the tire would rub lightly on the exposed ends of the rear shock mounting bolts. Nothing serious, just enough to keep them nicely polished. Of course the bulge of your 17" sidewalls might miss them and make first contact elsewhere.

I can say with certainty that a 265 will fit on a 7" rim. In this case a 265/50-14 but if a 265/50 will fit then a 255/40 will too. There is an advantage to this on street machines which is often overlooked. Curbs. If you've ever mounted tires on wider rims and then parallel parked or gotten too close to the curb in an apex then you know what I mean. Wheels do not protect sidewalls nearly as well as sidewalls protect wheels. In my opinion an extra 1 to 1-1/2" of sidewall sticking out past the rim is good insurance. With lower aspect tires you might need less to prevent tread wrap, and if it's a track car it doesn't matter. But for street driving it's very nice to know you aren't going to scrape or bend a rim if you get a little close to an obstacle. And in terms of travel time, being able to cut the corner that close is worth as much as a stiffer sidewall from wider rims. Easier to bead them up too. Any tire shop will happily balance them for you, even if they might have had concerns about mounting them.

Jim

What is the widest tire that someone has mounted on the stock rostyle rims which I think are 6".

Stock Rostyles are 5". I run 195-60 in rostyles widened to 6". The LE wheels that I'm trying to sell have 205-60 on 5.5" wheels.

Tire and rim association suggests 175-185 is optimized tire size for a 5" rim

I've got a friend who's been running 195/60x14" on his 5" RoStyles for a few years now.