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MG Midget and Sprite Technical - pushing rear arch out a bit..

How have you square arch people done it?

Could do with bringing the passenger arch out about 1/4 of an inch.

Have got 2 ton bottle jack and angle iron across wheelarch, it's just bending the angle (bed iron size)

Car is apparently bloody strong here.

Any tips? It's a rwa.
Rob Armstrong

Rob,
first thing you can do is bend the flange edge up a bit along the top of the arch - gains 1/4" to 1/2" or so.
After that I used a scissor jack with a bit of steel bar (or angle, I forget) to act as a spreader. It tended to spring back so I wound up the tension and left it overnight. Seemed to work OK.
Guy W

Arie did his 1500 swa with a baseball bat, and it turned out factory spec perfect

Prop
Prop and the Blackhole Midget

to clarify, I don't need clearance, the mumford link's keeping that under control (got no catching), I just need a bit more width to cover the tyre from above. Going to attempt baseball bat trick tomorrow,then might leave for a bit under tension :)
Rob Armstrong

I also saw a Youtube clip of someone spreading a rear wing of a modern car by putting a paperback book between the wheel and the arch with the car jacked up and then lowering the weight of the car onto the book - must have been very thin metal!
Nick Nakorn

Yikes! It's definitely stronger than that!
Rob Armstrong

Like this Rob.

You'll see that my arch had already been filled, so I wasn't too bothered about what might happen. It's a fork stanchion from a Triumph Bonneville btw, just in case anyone asks.

I simply inserted it at the rear, and rotated the wheel to pull the tube through the gap.

One thing I should add as a word of caution, I think it put too much stress on the wheel bearing. About 3 months later I had to change it due to play. But other than that, it gained over 1/2" of extra gap. Mine was very close prior to that, due to it being a badly fitted half rear replacement(by me) yonks ago. :(.

Lawrence Slater

Do it towards the back of the arch, (where the tyre periphery intersects the arch) not the centre, as the arch is wider at the front and tapers inwards at the rear.
You can get about 5mm permanent deformation without causing a wrinkle in the wing (Found that the hard way).

Yes, there will be spring-back, getting towars 10mm IIRC. I take it to 10, then let the jack off and see if anything's been gained. Then 5mm more each time and let go and measure until the permanent deformation takes place.

Did our first one with a 1 ton jack and a block of wood to spread the load. Second one was easier, used a port-a-power. But young muscles and 2 ton should do the trick, just be brave!

Guy - the lip of the wheelarch doesn't gain anything significant on a SWA Midget (I realised when I'd ground back the first one as far as I dared). Have a look at the shape of the wing immediately above the arch - it steps outwards, then down and then finaly the lip/flange turns in - but it ends in line with the inner arch above.
So the tyre won't contact the flange, but it rubs on the inner arch instead. Though the arch isn't as sharp!
Paul Walbran

Lawrence, did you use the weight-of-the-car method or did you lever the tube outward against the tyre?
Nick Nakorn

Nick,
The car was jacked up so the wheel was off the ground.

The tube was fed in from the rear of the arch, as the wheel was rotated anti-clockwise. This forced the tube between the wheel rim/tyre rim (I over inflated the tyre to make it as solid as possible), making the tube "roll" along the length of the wheel arch.

The tube of course, was greater than the existing gap between the arch and wheel rim. Hence something had to give, and as you can see, some of that "give" was in the filler. However not all of it was filler and the arch was moved out by a significant amount.

The amount of increased gap is sufficient to stop my previously rubbing tyre rim from contacting the arch.

Nick.
What about the banded wheels you mentioned in the other thread? Who did them? Are they good? How much?

Lawrence Slater

Is this clearer?


Lawrence Slater

Yes... very clear ... great idea

Prop
Prop and the Blackhole Midget

Thanks gents. Still nothing with the 2 ton jack. Bit of wood levered off the rostyle rim worked a bit with me jumping on the end of it. Think the rwa shell is very very strong here, but I've managed enough to cover the tyre from above.
Rob Armstrong

a bit heath robinson, but I only needed a very small stretch over the new tyre.

Rob Armstrong

and from above - tread covered :)

Rob Armstrong

Lawrence, Cheers for the extra pics.

I had the Rostyles banded by a very helpful bloke called Damian in Tiverton (Devon) at http://www.bandedsteelwheels.co.uk/. The turnaround was very quick - I delivered on a Monday and Collected on the Friday. He only does banding, blasting and powder coating. As far as I could tell the quality of the work was excellent even though his workshop was quite a mess from all the grit getting everywhere. I did not go for the powder coating as he was not entirely happy with the quality of the finish he was achieving in the colour I wanted. He was, though, changing his powder supplier to rectify the problem. The banding was £40 per wheel and I also paid £15 per wheel for a coarse grit blast. I have a small low pressure cabinet but it takes forever for me to do a wheel.

Time will tell if the work is as good as it looks when I get to drive the car - that won't be for a while. But Damian has been specialising in banding for a number of years and he's very busy so my expectation is that the wheels will be as good as they look.

Nick Nakorn

Rob. I wrongly thought you had SWA's. Obviously the method I used wouldn't work on a RWA.

Nick.
Thanks for that. I've been looking into this for a set of original Sprite hub cap steel wheels, to fit 165's on them more comfortably.
Lawrence Slater

Dunno if anyone else has had to push out a rwa before. There's no way on earth you'd get these on an swa without major reconstruction!
Rob Armstrong

I eased out the arches using a bottle jack and a piece of timber - one word of caution - dont overdo it, its a lot harder to push back!

S G Macfarlane

I solved the problem wit a panard rod. It worked for me
Flip
Flip Brühl

Hey S G Macfarlane, those arches look super-neat. What size wheels and tyres are under them?
Nick Nakorn

This thread was discussed between 08/03/2014 and 16/03/2014

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