Enigma concerning new wheels/tyres

[tyasman]

I have a 1970 Elan S4, standard in all respects. When bought, it had Pirelli P1000 165/80 R13 tyres fitted. Absolutely no problem with them whatsoever (except my mechanic says the car will handle better with 165/70 tyres.
I have just bought a set of Minilites from KN Wheels at Telford and re-fitted the 165/80 tyres. Driving out of the garage there was a scraping sound from the rear. Also, one of the steel spacer rings did not sit flush to the wheel and the wheel was difficult to locate on the pegs. Thinking there was too much paint, we reamed out the peg holes on the new wheel. This made it fit better, but the ring is still not fully flush. We tightened up all the spinners and I drove home to the sound of scraping from the back, particularly round corners. When I got home I noticed the tyres had been rubbing on the wings, and the tyres projected beyond the wing. I fitted an original steel wheel with an old 165/70 tyre and the tyre fits nicely inside the wing arch. I have measured the original steel wheels and the new Minilites, including the distance from the inner rim to the peg holes. All dimensiuons are identical to both wheels. Here's the enigma. If the new wheels are identical to the old wheels, why won't the car accept the 165/80 tyres? I was going to buy some 165/70 tyres next year, but the Pirellis are unworn and I would like to use them for a bit longer. HELP!

[Elanman99]

Your predicament is absolutely a normal scenario, that crops up fairly frequently here on this forum.

You say your S4 is standard but you have just fitted new wheels which being Minilites are almost certainly wider than the steel wheels so its not standard now!

Steel wheels have 4 1/2"" rims and the usual alloy Minilites are 5". If the wheel internal offset is identical on both wheels then the extra 1/2" is on the outside only so its moved the tyre sidewall closer to the wheelarch.

In one way you are lucky with both tyres rubbing (only one tyre fouled the arch on my car) because it means that the body is sitting symetrically on the chassis.

I fitted (bolt on) Minilites in 1972 and I wore an eliptical hole in the bodywork, although that took quite a while. One possible fix for your car is to trim away the return edge of the arch, if that is where contact is being made, but build up the thickness of the fibreglass to put the strength back.

I have no experience of the knock on Minilites but I suggest you investigate the non contacting 'washer' before using the car.

Ian

[tyasman]

Thanks Ian.
Before I put a brand new set of 5" Minilites on Ebay- as I really don't want to cut away the arches and re-paint, (it'll never look perfect and I assume it will be expensive), what about this as an idea.
If I fit 165/70/R13 onto the Minilites will they still catch the wing? Thanks for your reply,
Simon

[Higs]

From a geometric point of view, the tyres are the same width i.e. 165mm. The only difference is the height of the sidewall. The major effect of this will be a reduction in diameter of the wheel/tyre - from just under 60cm to about 56cm.

So if the tyre is rubbing part of the bodywork that is sloping in, the smaller diameter will help - no by making the tyre thinner but by requiring more suspension compression before it rubs. Whether it will solve the problem is more difficult to say - if the rubbing only occurs at near full suspension compression then it might.

The lower profile tyre also has a stiffer sidewall (because of the lower profile). Whether this makes it better or worse is hard to say.

The new tyres would also cause the revs to be higher for any specific speed (by about 5%). Not sure whether this is what you want.

So - a bit of a gamble?

You could I suppose minimise the risk by buying one tyre only to test?

But first off, as Ian says, is to solve the wheel / spacer issue...

Richard

[elansprint71]

See also this thread:
http://www.lotuselan.net/forums/elan-f15/minilites-clearance-t26009.html

Something else to look at- have you had the skinny springs and perches fitted? If not, check the clearance between them, you may be wearing a groove on the inside edge of your tyre walls. See here:
http://www.lotuselan.net/forums/elan-f14/tyre-spring-perch-interference-t25171.html

[tyasman]

Richard
Thanks.
I have a spare smaller tyre so I'll try it as a tester, then if still no good will go and have a good cry.
Simon

[Elanman99]

Simon

The fibreglass mod I mentioned does not involve any painting. Obviously it depends where your wheel/tyre combination actually touches the arch. On my car the hole was a long (40mm) slit about 20mm up from the edge of the arch but the other side of the car had lots of clearance. When I fitted a new chassis I was able to centralise the chassis in the body and now with the arch return edge trimmed down have plenty clearance each side.

What are the 'spacers' you referred to? I would not think you need any spacers on the hub face and the only other thing is the conical seating washer for the wheelnut. Is that what you meant?

Ian

[abstamaria]

Ian, as noted in the thread referred to above, also check the insides of the new rims to make sure your wishbone ends haven't been wearing a groove in them.

In your shoes, I would fit 155s. They look best, IMO (and are what God and ACBC intended). Good luck!

Andy

[tyasman]

Hello Ian
The "spacer" I refer to is the stainless ring which fits onto the wheel and against which you tighten up the spinner. One of them does not seat properly, (possibly a surfeit of paint) although the spinner is tight and didn't come loose when I drove 10 miles home. I have an idea that the wishbone ends may also be scraping the inner wheel, so next action is to a/ get under the car and have a good look and b/start swapping tyres/wheels etc. etc and see if I can find a solution that won't cost me money (I'm a Yorkshireman). Maybe the 155's mentioned above are an answer, but won't that affect the gearing even more? I replaced the original diff. with the higher geared version from an Escort Mexico a couple of years ago, and it is much more relaxed at 70+ cruising speeds.
Thanks for comments from all
Simon

[CBUEB1771]

I have just bought a set of Minilites from KN Wheels at Telford and re-fitted the 165/80 tyres.

When you say "Minilite" in the context of KN Wheels I presume you mean the Minator wheels made by KN in a Minilite-like pattern. The KN web site does not provide much information except that the narrowest 13" diameter wheel is 5" wide. This had been noted elsewhere in this thread as a likely problem. What is the dimension from the plane that contacts the hub flange to the inboard rim flange?

[Elanman99]

Two Gates, Minilites, Minators, Tech Dell, KN.... Now I'm confused!

When this thread started I just read Minilite and added my comments thinking they would be directly relevant to Simon. in some respects they are but only in a general sense as we are not talking about the same hardware.

The wheels I bought in 1972 (Minilite 'Sports') were made by Minilite as cheaper aluminium copies of their own magnesium wheels. 8 years ago as a result of damaging one wheel I bought a new set of Minilite wheels from Tech Dell (who I vaguely remember being located in Telford) and I understood they had them cast at the nearby 'Two Gates' foundry.

Th whole replacement wheel industry seems a bit incestuous, or maybe its my imagination!

Ian

[CBUEB1771]

When this thread started I just read Minilite and added my comments thinking they would be directly relevant to Simon.

I understand completely. I presume these are what Simon has, although the web site does not have any information about peg drive wheels:
http://home.btconnect.com/knwheelsltd/products.html

[msd1107]

Many people have written about this general problem. Here are my experiences.

I have had '68 early S4 and '69 S4 with knock ons, and have run with 155-13 4.5" rims, 5.5" rims, 165-13, 185/70-13 and 185/60-13, all with different problems.

Going to 165-13 and/or 5.5" rims, there will often be interference with the rear spring collar, wearing a groove on the inside of the tyre. Often you can use a mallet to flatten the spring collar slightly or secure it to the upright. This is only a partial solution, you eventually need to go to small diameter rear springs and corresponding collars.

If you are lucky, there will be no or minimal interference with the wheel well fiberglass. If there is interference, you can usually grind away the offending fiberglass.

Going to 185/70-13 or 185/60-13 produces more problems. There will be more interference on the inside of the rear fender, especially noticeable on bumps. Look up inside to see the black marks and grind away the offending fiberglass. There will be interference both at the bottom of the lip and part way up the fender. Depending on the tyre manufacturer and car difference, you may have to take away fiberglass until you reach the paint layer. Stop at that point(!) If you are careful enough, the car will cover tens of thousands in that condition and you can have the body shop carefully reshape the fenders when you eventually repaint the car. But some owners report wearing through the paint, so it depends on how lucky you are.

Interference at the front is usually when the wheel is cranked over and you hit a bump. You can grind away at the inner of the front wheel lip but the usual solution is to slow down when the wheel is cranked over and you encounter rough or bumpy terrain.

Best of luck.

David
1968 36/7988