Toyo Proxes T1R - always this bad?
Discussion
I recently swapped my mk1's rear tyres to Toyo Proxes T1Rs (195 55 15), and since then the car has had a slightly unsettling rubbery feel at the rear.
This reached a point today where the back end seemed to dig in or bounce on the left side going around a roundabout, and I was sure I must have a puncture or very low pressure. Checked at a garage and found the usual 25 to 26 PSI in all 4 tyres.
I took the wheels off and checked all the suspension but all seems in order, so I thought I'd swap the tyres front to rear, so the Toyos are on the front.
Took it for a spin and nearly soiled myself at the first corner as I turned the wheel and nothing seemed to happen. After a bit more experimenting it seems the car now has a really nasty rubbery feeling at the front, the steering sharpness is gone and for the first time ever the car understeered.
I tried a few medium to hard stops and it locks the front wheels with incredible ease, and the surface of the tyres are starting to develop little rubber marbles on them.
The back end with the Champiros now feels rock solid and grippy and sharp again, as it did before the Toyos went on.
Frankly I'm not going to drive it again in this state as whichever end the Toyos are on feels dangerously unpredictable, but I wondered perhaps if I have the pressures wrong or they take more than a couple of hundred miles to bed in?
This reached a point today where the back end seemed to dig in or bounce on the left side going around a roundabout, and I was sure I must have a puncture or very low pressure. Checked at a garage and found the usual 25 to 26 PSI in all 4 tyres.
I took the wheels off and checked all the suspension but all seems in order, so I thought I'd swap the tyres front to rear, so the Toyos are on the front.
Took it for a spin and nearly soiled myself at the first corner as I turned the wheel and nothing seemed to happen. After a bit more experimenting it seems the car now has a really nasty rubbery feeling at the front, the steering sharpness is gone and for the first time ever the car understeered.
I tried a few medium to hard stops and it locks the front wheels with incredible ease, and the surface of the tyres are starting to develop little rubber marbles on them.
The back end with the Champiros now feels rock solid and grippy and sharp again, as it did before the Toyos went on.
Frankly I'm not going to drive it again in this state as whichever end the Toyos are on feels dangerously unpredictable, but I wondered perhaps if I have the pressures wrong or they take more than a couple of hundred miles to bed in?
Thanks for the info, I will give them a try at 30 and see how they feel then before I swap them for something else.
After a bit of research I've found a few other instances where people experienced the same thing where the rear end feels squashy and prone to a sort of rubber-band effect when changing direction where it bounces into line, which is what I was experiencing, and also 1 occurrence of the sidewall folding over which is i think what happened to me earlier.
I'm a bit disappointed though as the car was able to stop faster with no locking in the rain with the Champiros than the Toyos can manage in the dry, which is not what I was expecting, and the feel of the Champiros is razor sharp in comparison too.
After a bit of research I've found a few other instances where people experienced the same thing where the rear end feels squashy and prone to a sort of rubber-band effect when changing direction where it bounces into line, which is what I was experiencing, and also 1 occurrence of the sidewall folding over which is i think what happened to me earlier.
I'm a bit disappointed though as the car was able to stop faster with no locking in the rain with the Champiros than the Toyos can manage in the dry, which is not what I was expecting, and the feel of the Champiros is razor sharp in comparison too.
Richyvrlimited said:
1) Stock tyre size is 195 50 15. You're running more sidewall than you should be
It has Rays Mazdaspeed wheels on it, which I brought over from my old 1.6, so both cars have always had that size tyre on it for about 8 years+, and they have always handled fantastically well.Anyway I couldn't put new 50s on the rear with it having 55s on the front.
I'll try 30psi and see what happens.
Edited by anonymous-user on Monday 22 September 22:19
I've tried them at about 30 to 31 psi, and although it's a bit better the steering sharpness and immediate turn-in that I was getting from the Champiros is still missing. There is still a slightly unsettling vagueness about the front end, more akin to winter tyres where you have to turn the wheel and wait for the car to catch up.
Braking performance is still woeful - it will lock either or both front wheels on a dry road with what I would class as medium braking effort, ie braking hard but not as much as you'd want to use in an emergency stop.
Cornering grip seemed OK but if the braking is still bad I've no reason to believe they will grip sideways much better than they did before, which was also terrible.
The tyres have been on both ends of the car for perhaps 4 months in total now, not certain of exact mileage but it's much more than just a couple of hundred miles so they've had plenty of chance to bed in a bit, and they're spoiling my enjoyment of the car completely so a new pair of Champiros will be going on ASAP and these can be kept as emergency spares or sold.
I just have no trust at all that during cornering the sidewall wont suddenly fold over again and let the rim fall dangerously close to the ground, luckily I got away with it last time but not taking that chance again.
Also the MX5 is a small very old car with bugger-all safety features, so I want to be able to stop as quickly as is possible the next time someone somehow fails to see it.
Braking performance is still woeful - it will lock either or both front wheels on a dry road with what I would class as medium braking effort, ie braking hard but not as much as you'd want to use in an emergency stop.
Cornering grip seemed OK but if the braking is still bad I've no reason to believe they will grip sideways much better than they did before, which was also terrible.
The tyres have been on both ends of the car for perhaps 4 months in total now, not certain of exact mileage but it's much more than just a couple of hundred miles so they've had plenty of chance to bed in a bit, and they're spoiling my enjoyment of the car completely so a new pair of Champiros will be going on ASAP and these can be kept as emergency spares or sold.
I just have no trust at all that during cornering the sidewall wont suddenly fold over again and let the rim fall dangerously close to the ground, luckily I got away with it last time but not taking that chance again.
Also the MX5 is a small very old car with bugger-all safety features, so I want to be able to stop as quickly as is possible the next time someone somehow fails to see it.
Edited by anonymous-user on Wednesday 24th September 08:03
MX-5 Lazza said:
They certainly aren't shockingly bad and won't ruin any MX5.
Well what I have experienced certainly points to the opposite:1. the fronts lock at the slightest sign of hard braking.
2. first time I've ever had understeer in an MX5.
3. the left rear sidewall folded over as I took a roundabout, leading to the car suddenly dropping and bouncing sideways.
4. the steering feels numb and vague and cornering becomes a 2-stage process of turn and then see what happens.
5. 26 or 30 psi made no real difference to the steering feel of the car, and no difference to the braking performance.
They have certainly ruined my car and the incident with the rear folding over could easily have ended up a lot worse.
Oldandslow said:
Can you post a photo? I have no idea how that could happen. I drive like my arse is on fire around twisty country roads and nothing even remotely like that ever happens?
How are you measuring the pressure? Have you tried a different gauge?
I am guessing that is what happen based on a few other accounts of similar that I found after some searching around. I was taking a roundabout and as the rear left loaded up there was suddenly a huge jolt and the rear left of the car felt like it had dropped onto the road, and the entire car then sort of bounced sideways. I know the roundabout well and have driven this car and my old 1.6 that way lots of times, and there are no drains or dips etc, so something physically happened to the tyre to drop the car down enough that I could feel it from the drivers seat. My immediate thought was that the tyre had either come off the rim or deflated very fast, but as I exited the roundabout it all seemed normal again.How are you measuring the pressure? Have you tried a different gauge?
I checked the tyre pressures with a garage pressure machine and then back at home with the footpump that I normally use, and both gave the same values to within 1 PSI.
I didn't notice any visible damage to the tyre but I will check it again.
My main concern is that whatever happened to that tyre happened very suddenly and not under extreme cornering load, and if the sidewall did fold (and I can't come up with any other explanation for such an odd event) then if I was going faster it could have resulted in the rim edge hitting the ground, and the results of that could be very serious.
It could well be that at 30psi they would be fine, but they are on the front of the car at the moment and they seem to have no ability to stop the car quickly, so I have lost all faith in them and will be swapping them.
Yes clearly having 5% less sidewall or whatever it works out as is highly likely give it way more grip and make it razor sharp...
Your definition of s***e is apparently a tyre that grips better, turns instantly with no vagueness, and stops quicker in the rain than the better tyre can manage in the dry. OK, but I'll take the s***e one then.
Your definition of s***e is apparently a tyre that grips better, turns instantly with no vagueness, and stops quicker in the rain than the better tyre can manage in the dry. OK, but I'll take the s***e one then.
I checked about an alignment setup a while back, but I never got around to getting it done. I'll see if I can sort it at some point soon.
About the old tyres "masking" the problem - (ignoring the fact that the Champiros feel razor-sharp in comparison when changing direction) they have the ability to stop to car far far better than the Toyos can manage, even on a wet road they could stop it like i'd hit a wall, whereas the Toyos lock the fronts at the anything above moderate pressure on a bone-dry road.
The car has always handled really well as far as I can tell, it feels almost identical to both the 1992 1.6s I had before, so unless all 3 cars had the exact same alignment issues then it's likely they were all setup OK, probably not perfectly, but OK enough that there are no nasty handling traits.
Even if the alignment is out, the Champiros still have a far better ability to stop the car and corner than the Toyos do, and if the Toyos are *that* dependent upon the setup to have any grip at all even in a straight line, then that doesn't strike me as a particularly good tyre for every day use - every time I would run over a pothole (which lets face it is pretty much unavoidable nowadays) I'll be wondering if the alignment is messed up again and the tyre is back to having no braking ability.
Next time I swap tyres then I will go to a 50 sidewall as I had no idea that 55 was not the right size for that rim, but I dont really want to throw away 2 more perfectly good tyres for the sake of about 9mm.
About the old tyres "masking" the problem - (ignoring the fact that the Champiros feel razor-sharp in comparison when changing direction) they have the ability to stop to car far far better than the Toyos can manage, even on a wet road they could stop it like i'd hit a wall, whereas the Toyos lock the fronts at the anything above moderate pressure on a bone-dry road.
The car has always handled really well as far as I can tell, it feels almost identical to both the 1992 1.6s I had before, so unless all 3 cars had the exact same alignment issues then it's likely they were all setup OK, probably not perfectly, but OK enough that there are no nasty handling traits.
Even if the alignment is out, the Champiros still have a far better ability to stop the car and corner than the Toyos do, and if the Toyos are *that* dependent upon the setup to have any grip at all even in a straight line, then that doesn't strike me as a particularly good tyre for every day use - every time I would run over a pothole (which lets face it is pretty much unavoidable nowadays) I'll be wondering if the alignment is messed up again and the tyre is back to having no braking ability.
Next time I swap tyres then I will go to a 50 sidewall as I had no idea that 55 was not the right size for that rim, but I dont really want to throw away 2 more perfectly good tyres for the sake of about 9mm.
rb5er said:
MX-5 Lazza said:
Running 55 profile won't be the problem. As you say, the difference in tyre wall in small.
Totally disagree. 10mm or so extra sidewall is definately noticeable especially on the T1R. It will cause some nasty unwanted characteristics as are being felt by the OP.MX-5 Lazza said:
Also, tyre size makes no difference to pressure .
Errrmm Yes it certainly does.Flatinfourth said:
The consequent step up in sidewall control was huge, with lap times to match. Your car on 55s would need very high tyre pressure to even begin to combat the sidewall movement on the same rim, absolutely no doubt you have the wrong tyre and are critisizing its manufacturer inappropriately when the issue is in fact poor tyre choice
Exactly. Edited by rb5er on Saturday 27th September 09:43
So, what pressure should it be run at? I'm quite willing to give it a try at higher pressures than 31 and see what happens.
Theres no point just stating that its the wrong tyre for the car and all the problems stem from that - it must be designed for some vehicles so what would happen if I just move the rims over to a car that runs 55s as standard? The handling quality and soft sidewalls are not going to magically change just because the rim is on a different car.
This 55 tyre is on a rim that fits the big hole in the middle, beyond that I can't see how anything about it being an 1 ton MX5 at the other end of the wheelbolts and not a 1 ton VW or an old Pug 205 or whatever will affect the total lack of grip and soft sidewalls.
Edited by anonymous-user on Saturday 27th September 12:51
Right I've taken the plunge and ordered a full set of 4 brand new 195 50 15s, to be fitted next Saturday. Hopefully then I can enjoy driving the car again. I'm not telling you what brand as then I'll get told they're crap or something 
They're not Toyos though.
I'll keep the Champiros as spares, not sure what to do with the Toyos, perhaps use them as planters in the garden...
They're not Toyos though.I'll keep the Champiros as spares, not sure what to do with the Toyos, perhaps use them as planters in the garden...
Yes yes, I know you're convinced the alignment must be so far out that the tyre can't even stop in a straight line, but seeing as the car handles what I would consider to be perfectly on all the other tyres its had (and feels identical to my two previous mk1s) I find it unlikely that an alignment would change it that much.
It's also not going to change that terrible vague feeling you get as the sidewalls flex around, and unless I run the tyres rock-solid at 50PSI or something daft it seems that it just a characteristic of the tyre, and one that I don't like at all, whether the tyres on are on the front or the rear.
It's also not going to change that terrible vague feeling you get as the sidewalls flex around, and unless I run the tyres rock-solid at 50PSI or something daft it seems that it just a characteristic of the tyre, and one that I don't like at all, whether the tyres on are on the front or the rear.
The difference is though that I wasn't one of those people who wondered what all the fuss was about - my MX5 handled superbly until the Toyos went on. Even if the alignment fixed some of the Toyo's problems, I couldn't live with the other problems such as the soft sidewalls and resulting vagueness and rubbery feel.
Anyway, hopefully these new tyres will sort it all out, if not then an alignment will be the next thing to do.
Anyway, hopefully these new tyres will sort it all out, if not then an alignment will be the next thing to do.
No update on whether the new tyres are better yet - it was raining so hard on Saturday that I just collected them in my normal car and will get them fitted later, so they're currently sat in the garage piled on top of the mx5.
Probably it will be a few weeks now before I get the chance though which is annoying but I'll try to remember to post here to say whether or not they've made the car handle and stop properly again or whether an alignment etc.. is needed.
Probably it will be a few weeks now before I get the chance though which is annoying but I'll try to remember to post here to say whether or not they've made the car handle and stop properly again or whether an alignment etc.. is needed.
An update on the new tyres finally, having had them fitted today as it was sunny and warm for the first time in ages.
They are Kumho Ecstas and are R50s rather than the R55s I had before. I've only done about 20kms so far but first impressions are excellent - having swapped the Toyos between both ends of the car the difference on the new tyres is quite marked - the turn in feels sharp again and the vague floaty rear end that the Toyos gave when they were on the rear is gone.
Also dry braking seems hugely improved, despite the tyres being brand new - I did a couple of hard stops and it pulls up hard enough to make it physically uncomfortable and without any sign of the tyres locking.
I still think the Champiros gave the best feel to the front end in terms of direction change, but its early days on these so I'll see how they go.
All are set to 26 psi at the moment.
They are Kumho Ecstas and are R50s rather than the R55s I had before. I've only done about 20kms so far but first impressions are excellent - having swapped the Toyos between both ends of the car the difference on the new tyres is quite marked - the turn in feels sharp again and the vague floaty rear end that the Toyos gave when they were on the rear is gone.
Also dry braking seems hugely improved, despite the tyres being brand new - I did a couple of hard stops and it pulls up hard enough to make it physically uncomfortable and without any sign of the tyres locking.
I still think the Champiros gave the best feel to the front end in terms of direction change, but its early days on these so I'll see how they go.
All are set to 26 psi at the moment.
Gassing Station | Mazda MX5/Roadster/Miata | Top of Page | What's New | My Stuff