14 replies to this topic

[Will16]

Quick Spec of the car

-Avo lowered shocks
-Lowered on hilo's
-New front cones, rears done 2000 miles
-10x6 wheels
-A032r fronts, 6 months old, 30psi
-165 Falkens rear, 1 year old 28psi
-solid mounted front subby
-1-1.5 neg camber in front
-about 1 neg camber on rear and toe in

Been driving mine about recently and it seems to have a bit of a floaty feeling. It's hard to describe, but when going 50 - 70mph down straightish roads the car feels quite floaty, especially from the rear and going down lanes and through corners (similar speeds) when you turn in the car feels like it's leaning and the front goes a lot faster round than the back.

It's only sort of done this since I put a032r's on the front. It still handles, and goes round corners well but just doesn't feel as 'secure' as it did with Falkens all round. Would the different tyres lead to this? Should I adjust tyre pressures?

Cheers,
Will

[gazza82]

Try with newer tyres on rear. That's the correct way.

[Will16]

Try with newer tyres on rear. That's the correct way.

Really? Always been told grippier and newer tyres on the front?!

[1984mini25]

 

Try with newer tyres on rear. That's the correct way.

Really? Always been told grippier and newer tyres on the front?!

 

 

A lot of tyre fitting centres (Costco being one) will only fit new tyres to the rear if only buying/fitting two.

 

The reason being in a fwd car you have no control of the rear (or your average driver) if the gripper tyres are on the front.
 

The situation being by hard braking, turning in too hard, and lifting off too harshly (i.e. braking and swerving to ovoid something), shifting all of the weight onto the grippy front tyres, back end goes light, swings round and the only way to save it is to floor the throttle and spin the fronts up to pull the car back into line. Only problem being, as the harsh braking, turn in and lifting off harshly is normally for a reason (driving too fast,avoiding an accident, etc) the last thing you are going to be doing it flooring the throttle to get out of trouble.

 

If the front loses grip, with the less grippy tyres, its easily corrected by lifting off and driving slower, more smoothly.

 

Although ideally, you're better off with tyres of the same make and as near equal tread depth all round.

 

Edited by 1984mini25, 15 September 2016 - 10:19 PM.

[nicklouse]

As mentioned new tyres on the rear.


But I would say your tyre presses are a tad high. Can't say my memory is great but I thought I ran road tyres a few psi less than you are.

[1984mini25]

From memory 1.7 bar / 24 psi for 10's and 1.9 bar / 28 psi for 12's. -  quoted form the blue Haynes manual.

Edited by 1984mini25, 16 September 2016 - 04:52 PM.

[sledgehammer]

first as above -

 

tyre pressures / condition - I go with higher pressure at back - for less side wall flex , lower at front - pressure depending on weight / tyre spec

 

higher at front will make rear feel loose (as side wall flexes a bit) if more than a few psi

 

rack mounts tight ? rear subframe mounts ok ?

 

are the radius arms ok ? - slack in the pins can make rear wheels steer slightly - giving floating sensation at the rear

[Mini Manannán]

I've always gone with 30psi all round.   That's the easiest thing to try first, you might find the Yokos need a different pressure to get in the groove.

[Will16]

Thank you all very much for the input. I'll lower the pressures down, thinking 26 psi front, 24 psi rear. I'll swap the yoko's to the back and give it a ride out.

I'm pretty sure all mounts are tight, rack, subby, I'll try the radius arms too. I have a set of poly rear subframe mounts waiting too.

Hopefully this will sort it out as I have some track time round Combe tomorrow!

[gazza82]

 

Try with newer tyres on rear. That's the correct way.

Really? Always been told grippier and newer tyres on the front?!

 

 

Two tyre dealers near me both have signs in the waiting area now informing customers if they only buy two new tyres, they will be put on the rear and wheels swapped if necessary and this is on safety grounds.

 

It's safer to understeer (the front end slips) than oversteer (where the rear loses grip) .. unless you are drifting but they you will need a rwd car not a Mini!

Edited by gazza82, 16 September 2016 - 10:43 AM.

[Cooperman]

Of course that only works when all tyres are the same size! My road car has 275 on the back and 245 on the front as standard.

I am surprised at the low pressures some use. On my Minis I normally run at 30 psi all round and fit new tyres on the front as I wear the fronts out more quickly.

[Will16]

 

Try with newer tyres on rear. That's the correct way.

Really? Always been told grippier and newer tyres on the front?!
 

 
Two tyre dealers near me both have signs in the waiting area now informing customers if they only buy two new tyres, they will be put on the rear and wheels swapped if necessary and this is on safety grounds.
 
It's safer to understeer (the front end slips) than oversteer (where the rear loses grip) .. unless you are drifting but they you will need a rwd car not a Mini!

Learn something every day! Definatly going to swap them and try it, I know all about oversteer and mini's and putting them into walls

[1984mini25]

 

 

Try with newer tyres on rear. That's the correct way.

Really? Always been told grippier and newer tyres on the front?!

 

 

Two tyre dealers near me both have signs in the waiting area now informing customers if they only buy two new tyres, they will be put on the rear and wheels swapped if necessary and this is on safety grounds.

 

It's safer to understeer (the front end slips) than oversteer (where the rear loses grip) .. unless you are drifting but they you will need a rwd car not a Mini!

 

 

 

Its also a pretty good way to get you to buy another 2 tyres in a few months time. When the part worns that were on the rear wear out on the front.

 

Still I'm forever replacing, wearing out n/s fronts on mine.

[Mini Manannán]

Thank you all very much for the input. I'll lower the pressures down, thinking 26 psi front, 24 psi rear. I'll swap the yoko's to the back and give it a ride out.

I'm pretty sure all mounts are tight, rack, subby, I'll try the radius arms too. I have a set of poly rear subframe mounts waiting too.

Hopefully this will sort it out as I have some track time round Combe tomorrow!

 

You really only want to do one change at a time or you won't know what worked.

 

If it were me I would be increasing the pressure to 30psi all round

[Cooperman]

If the 'floaty feeling' only started when new tyres were fitted to one end, then it is obviously the tyre difference which is causing the perceived problem.

 

Tyre pressures won't make a great deal of difference unless they are much too high or much to low. I still think around 30 psi is best for the classic Mini unless, perhaps, you have 175/50 x 13 where a lower pressure might help to replace some of the lost tyre compliance caused by the low depth sidewall.

 

First of all make sure the suspension is set to the optimum. With standard ride-height you need a small amount of negative camber on the front, no more than 1.5 degrees, with a 1 mm to 2 mm toe-out. On the back you need zero to minus 0.5 degrees negative camber with 1 mm to 1.5 mm toe-in. With adjustable dampers don't set them too hard as the suspension needs to work. That will ensure a nice neutral handling combined with good road-holding.

 

With that you can fit the better tyres on the front. Personally I hate any marked understeer and would rather go sideways around a corner then front first into a ditch or wall. Best really not to drive in a manner where either can happen as in either case you would be driving faster than you know how to. I always set my cars up to give power-on understeer and power-off oversteer. Just drive within your own limits and be safe.