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MG Midget and Sprite Technical - 135/70/13 tyres
|First of all, happy 4th July to those across the pond and south of the 49th Parallel!
I finally made up my mind and bought my 'Minilites' - Thank you Jonathon (JLH) - the best price and excellent, swift next day service.
I have always understood that the maximum size my square wheel arches would accommodate would be 165s and that 175 would only fit if the wing was modified, so I duly ordered a set of 165/70/13s which arrived the next day(absolutely staggered that it was my least favourite supplier who offered the best price - Halfords, and I had really good service from the Shrewsbury branch).
Imagine my disappointment then, when I found that these tyres fouled the rear wheel arches. I really didn't want to modify the wings but couldn't see any other option. After much grinding back and rolling of lips they seemed to fit OK but the first run out had them rubbing the inside of the wing on corners. Out came the old scissor jack and I have now 'bowed' the wings slightly so that I don't get any rubbing.
Have others had to modify their wheel arches and wings to take 165s? If so, how?
What is the 'standard' measurement from the chassis, just below the crescent lip to the outer edge of the wheel arch lip? Mine are now about 9 1/2".
I'm sure the fact that the rear end is lowered by 1 1/2" is a contributory factor but I'm sure that without the lowering the tyres would still have rubbed on extreme cornering. I also wonder whether I would have had fewer problems with 165/65s.
I know that a Panhard rod would reduce the lateral movement but suspension mods like that are not allowed by the MSA 'Roadgoing' class regs.
I know this topic was discussed at length recently and I have read every word of that thread several times. In that thread no-one commented on having problems with 165/70s on 5" rims so I thought I was going to be OK.
|Sounds like a mixture of issues and all really expensive
Most likely the back spacing is deeper on the mini lights and thats why your rubbing on the leaf spring to answer that question
Sorry to say, but you will need a panhard rod for everyday driving or your tires arw going to be short lived .... make the panhard rod removeable and take it off for track days
Next and you will need to check the racing regs but they make what is called a dovetail rear leaf spring for what is designed for tires that foul the leaf springs...there odd shaped leaf springs desighned to fo around the tire...google it
Ive been thur this learning experiance and it wasnt cheap or easy and took alot of creativity and time, in the end i beat it, and won, i got the wheels i wanted and i learned alot... but it was painful to achive
Basically the way i see it you have got 2 resonable options without spendimg rhe next year chopping at the deep weeds working thur the issues
A. The easiest, least expense, and the fastest...go back to your old wheels and buy new rubber in the same size as before....i know, but consider it
B. convert to round wheel arch, and but the wheels on 1 inch spacers between the hub and the wheel and upgrade your wheel studs from 3/8 to 7/16 ... by doimg this you can avoid a huge load of issues and you get the wheels and tire size you want without reinventing the wheel... which is exactly the path your on, you just dont know it yet. Also becuse your pushing rhe wheel out and by doing round wheel arches you can flare the round wheel arch and that looks nice
If you go down the path your on, be prepared to spend $1000 per wheel... and rhere will be one issue after the next that you didnt see, amnd you just chase your tail .
Those 2 options are the best of bread ... they make a nice inexpense round wheel arch for rhe ford mexico ??? ... ive seen that mod and thats a nice looking arch... ebay aound $50 per arch rhe last time i looked snd takes some massage work to fit
Do not do the fiber glass flared panalsx rhose are great for rhe race cars, bit bae for street cars
|C. Option that will work but looks like crqp....get the 145/ 13 inch tires and put those on the new wheels ... there factory size and small but does the job|
|They rubb like a teenager with a lingerie catalogue!|
On my midget that is even after grinding the lip and jacking the arch out.
I also know of a heritage bodied midget that fits 175 with just a little bit of grinding of the lip.
So not all midgets are created equal
|My 165s don't rub, though l did spread the wheel arch a little. But not all 165s are the same. Different brands of tyre have varying amounts of 'bulge' in the side walls. I had to move one pair of tyres to the front, whilst another ostensibly the same size cause no problem at all.|
|my 165 toyo's don't rub on standard rims|
|When I saw 135 13 I got all excited, at last 135 on a Spridget - but no.|
Some of thoughts have already been covered, differences in tyre walls, wheel offsets (5" rims?) and variances in Spridgets generally but I also wonder about rear axle axle location. Is it much off centre, is it held well by spring pads, bushes, damper and links.
I can't think of how the SWA wings go but I'd have also thought the 1 1/2" drop might not help.
He has new mini lite wheels... not the old lucas standard orginial 3 part welded steel wheels
like me Mark may be thinking of rim width, 4 1/2" for Rostyle steel 5" for the Minilite.
Least expensive alternative to check everything is lined up as best it can and everything is fitted tight and replace anything badly worn (as it'd need replacing anyway. Then second, I'd guess, change the tyres to 155.
|My thought for the day, then I'm depleted and exhausted for the rest of the day, are the axle, hubs, etc. standard and nothing added, taken away or oversized.|
I've garn dissy now.
|Those are the deep weeds im talking about
That nigel and guy are talking about.
Worn shocks with play, worn pads, axle not located exactly, body off a hair worn leaf springs tension , worn leaf spring rubber bushings...plus mods that produce more mods
For me... i got in, saw there was a problem and moved forward, then a new issue, and moved forward agian rinse and repeat, rince and repeat over and over ... and it became a case of im in to far deep and cant turn back now, have to see it thur to the end regardless of time and cost
I learned alot about wheels and suspension that spring summer and fall.
In the end, looking back.... glad i went thur it
Granted i still dont know how to spec size a tire after all that..(must be witch craft) ... haha
|Firstly, apologies for the typo in the title, and for giving Nigel a little frisson! A bit embarrassing really as my day job includes proof reading technical manuals!
Thank you for all the comments and advice.
The tyres - Yokohama Blue Earth AEO1s definitely bulge a bit, so that might account for some of the problem. My 155/80 section Toyos bulge a bit less.
Onno, that comment definitely needs explaining (but probably not via this medium!). I'm sure my rear wings have been replaced at some time and the lips were different so they may not be original BL/Unipart/Heritage ones.
Prop, all the rubbing has been on the outside of the tyres - no problem with clearance between wheel and spring. I hadn't thought about the part time Panhard rod - definitely worth considering. Long term, if I decide I don't like the bowed wings, I might go for a round arch modification but definitely no fibre glass.
Nigel, I considered centralising the axle, which is original, but the degree of rubbing was about the same on both sides, so I think it is about as central as it could be. Apart from the front metalastic bush, all the bushes and spring pads are red polybushes which are about three years old and I have checked everything for tightness.
I have telescopic shocks of unknown age so I guess renewing these might help a bit. These mount on the original mountings so, while canted forwards, are vertical laterally. Would angling them make a difference? If so, is it possible to do it by bolting on some sort of adapter to the original mounts so that it stays within the regs?
Having said all that, with the work that I've done so far I think it might be OK. We have three tight double bends within a mile of the house and when I took them 'briskly' on a run out earlier I didn't detect any rubbing.
Thanks again for the advice - plenty of food for thought.
|Simplest solution, fit a panhard rod or similar. Shocks won't help or hinder.|
the dampers may not help or hinder with this particular issue unless they are very worn but generally they can help or hinder quite a bit. The old push and count the bounce test would initially tell you if they're completely shot.
I've read that the dampers being more upright helps. I went from rear Spax on a lean to AVO more upright (as technical as I get there with terminology) and found it improved things but they were different dampers and other changes made so not a direct comparison.
I don't know the Yoko blu earth tyres but IIRC the Toyos you have are the 350 in which case it might be that neither are the most sporty of tyres, particularly to use in a sport, so could there be a lot of movement from them.
I liked Onno old-fashioned reference, I thought its meaning was very clear without being too course in polite society. :)
Below is a photo of somebody else's car with Spax fitted, with the fuel tank not fitted you can clearly see how much they lean.
Thanks for the photo - quite helpful. The dampers seem to be working well enough and pass the bounce test. It passed its MOT last month. The damper bushes are getting tired and stiffer ones might help but I've been unable to source a set that don't have dampers attached!
The Yoko Blue Earths are the replacement for your beloved A Drives, which went obsolete just as I bought the Sprite. They are much softer than the Toyos and, in the short mileage that I have driven on the Yokos they feel much better.
I will probably use the Toyos on the steel rims for road use to wear them out and the Yokos on Minilites for track and 'events' such as the line-up of classics at our local village fete. I see that Yokohama do the Blue Earths in 155 so will probably fit them when the Toyos are worn out.
Incidentally, another word of praise for Shrewsbury's Halfords AutoCentre who replaced my front balance weights FOC after I knocked them off as soon as I moved the car even though they are very thin. I knew from the other thread that they could be a problem, I forgot to mention it when I got the tyres and I just didn't realise how little clearance there is between the wheel and the TRE.
|Do I remember you're on the dreaded 350 Toyos, most tyres other than those might be better on a Midget, do yourself a favour and pass them on to someone who can make better use of them.|
MoT, minimum standard to one person's point of view at one moment in time not to good or high performance.
But good on Halfords for replacing the weights, when I done the same on mine the noise made me think something had broken and fell down, I only got a few yards down the road before I had to stop.
The advice we arw giving should be cosidard conceptial and broad ...wide angle lens mainly ideas thoughts and personal experiances ... no one here can provide the actual silver bullet to solve the problem unless we are there working on the actual issue at hand
Congrats on fixing rhe issue and its now performing much better then it was several days ago... sometimes tires have to settle in and find there grove, and sometimes we have to alter our driving styles to make a more comfortqble relationahip with out cars
Just a general thought what a happens at rhw front of rhe car can have huge repercussions at the back of rhe car... in time if your rubbing issue returns then id also look into your front susoension, brakes, and weight distribution
If you are going to make up brackets for mounting the rear shockers--
With the shockers mounted correctly, they will in fact help stop the rear axle jumping around sideways as well as up and down
The correct method of mounting them is to have the bottom mountings as far outboard as possible without fouling springs etc and then measure from the roll centre to the bottom of the shocker
The top shocker mounting point which will be more canted inboard should measure exactly(or close) to the same measurement from the roll centre with the car in it's normal sitting position
What about using the sprax mounting plates....there shocks have always been questionable but they seam to have a good system for mounts for telescope shocks
Of course there is peter cardwell at world wide here in the states with his borg like recreation of the amrstrong shock thats super rugged ... fit and forget and there dial in for the hardness you want and fit evertime cuz the use the orginal monting loctions... so ne need for specialty faberication plus cutting and welding of cages and mountings ... justbolt on a go, sure there expensive ... but so is this kind of modification work being considard...soit may still be cheaper and definatly a huge time saver using peter cardwell premium redisigned lever shocks...ive seen them, they are a work of art snd look very star trek borg ( you will be assimilated...lol)
This thread was discussed between 04/07/2017 and 08/07/2017
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