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Thoughts on replacement tyres on R53

5K views 10 replies 5 participants last post by  NigelK 
#1 ·
Hi all,

New mini R53 owner and also new to run flats and i hate them especially in the wet, i live in the country and the roads are not great to say the least and I'm finding the Copper S will move a good 12" when i hit a bump and in the wet that's not a great feeling, So my question is should i ditch the run flats once they come round to replacement (not that far off) and put on "normal" tyres or stick with the run flats

I know this could be subjective but wanted to hear peoples thoughts especially seasoned mini owners

Cheers guys

Paul
 
#7 ·
brassd, using the link you posted to go back to that post, I did the VIN check and my R53 has got the LSD. Can you give me a heads up please?
What happens if you fit a (smaller circumference) spacesvaer to one of the fronts? Does it knacker the diff? I'd presume that if a run-flat blew out on the front and you're driving on it, it's not going to be rotating at same rate as the OK/fully inflated run-flat tyre on the other side?

I'm going to have to go your (excellent, thanks) spacesaver route now. I've bitten the bullet. 4 x Non run-flats (205/45/17 from Camskill) should arrive tomorrow. Will get them fitted tomorrow or Thursday depending when they arrive.
 
#8 ·
brassd, using the link you posted to go back to that post, I did the VIN check and my R53 has got the LSD. Can you give me a heads up please?
What happens if you fit a (smaller circumference) spacesvaer to one of the fronts? Does it knacker the diff? I'd presume that if a run-flat blew out on the front and you're driving on it, it's not going to be rotating at same rate as the OK/fully inflated run-flat tyre on the other side?
Yes, the different rotational speeds of the two front wheels would cause wear on the differential after a period of time. You'd probably be ok for a few miles, but as I don't know the limits of what it can take, I would just swap the bad front wheel with a good rear wheel if I had to, and then the space saver goes on the rear.

I don't class myself as a mechanic, so I would advise further research until you are happy you have the correct solution.

I know it sounds obvious, but when you get the space saver try fitting it to the rear to make sure it actually fits.
 
#9 ·
Lol - cheers guys - yeah maybe it feels like it's a 12" as the roads are so s@@@ here, seems to feel like a slide on cornering (Wet Roads) moves on the same corners in the dry - just feels SOOO different as Ive never experienced RFs and yeah the first couple of times thought my bum would eat the leather seat!

I'll look to change to standard as suggested
 
#10 ·
Thanks brassd. I'm not a mechanic or engineer either. But thinking about how an LSD works, having 'odd' tyres would be like permanently going round a corner. LSDs cope with differential wheel speeds when cornering. I'm thinking it responds (and applies ‘limited slip’) in response to 'grunt/torque' rather than wheel speed.

I’m pretty sure that an LSD, which has clutches inside, detects that all the torque is going to/being taken by one wheel (that is spinning, say on ice, to take an extreme example) and so directs torque to the stationary wheel (a percentage, in the Mini 25%).

Not sure who to ask about this. Your average garage mechanic wouldn't have a clue! Could try KwikFit :).

I'm going to go for a Rover spacesaver, rather than a 'proper' BMW Mini one. They are a lot cheaper on eBay. Plus it is actually closer to the circumference/rolling radius of the 205/45/17 than the Mini one.
Standard 205/45/17 - rolling radius 194 cms = 100%
Mini is 115/70/15 - rolling radius 170 cms = 88%
Rover is 125/80/15 - rolling radius 182 cms = 94%

An issue may be whether the 15” will fit over the MCS brake discs. And the ET is different. Also it’s a little bigger in diameter so it might not fit as neatly as yours upright under the parcel shelf.
 
#11 ·
Apologies Viper, my posts here are a bit off topic, but it does relate to having a spacesaver as your spare if you go standard tyres.
I've just bought non run-flats from Camskill for my R53 (205/45/17 equipped) and they being fitted later this afternoon. I have great hopes that the hideous ride and crashing will be improved. Everyone says it will. I shall report back!!

brassd, if you are interested, this item in Learn Engineering is a detailed explanation of the difference between standard and limited slip diffs:
Working of a Limited Slip Differential ~ Learn Engineering

Inerestingly it says "However while taking a turn the LSD can act like a normal differential. In this case thrust force developed due to bevel gear separation action won’t be that high. So the plates in clutch pack will easily overcome frictional resistance and will be able to slip against each other. Thus the right and left wheel can have different speed just like an open differential".

So hopefully running different circumference tyres for a short while at low speed shouldn't harm it.
 
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