Discussion
My Chim handled very averagely when i first got the car. Standard set up with standard springs and shocks and SO3's on the back with bridgestone Turanzo or something like that on the front.
Since then I have changed the suspension for £1k's worth of specialist shocks and springs. Fully adjustable and had set them up fairly stiff but with enough movement for fast road use.
Saturday I changed the rear tyres for Toyo Proxis as the Bridgestones were down to legal limit. Checkedt he pressures and all OK. Went out on Saturday to start on the job of scrubbing off the lovely tyre coating and the handling was all over the show. In a straight line the car felt as though the back end was twitching all over the place at any speed higher than about 50mph. In view of the fact this was on a straight I was doubting how much the new rear tyres "coating" had to play in it.
Any ideas? Is it possible that the front and rear tyres are "mismatched" in that the fronts dont appear to be a very sports car based tyre looking at the tread pattern. I am truly
and after spending £2k on the chim in the last few months am loathe to throw yet more wonga at the car at the moment but saturdays drive really wasnt pleasant and that "seat of the pants" moment was too frequent by far.
Since then I have changed the suspension for £1k's worth of specialist shocks and springs. Fully adjustable and had set them up fairly stiff but with enough movement for fast road use.
Saturday I changed the rear tyres for Toyo Proxis as the Bridgestones were down to legal limit. Checkedt he pressures and all OK. Went out on Saturday to start on the job of scrubbing off the lovely tyre coating and the handling was all over the show. In a straight line the car felt as though the back end was twitching all over the place at any speed higher than about 50mph. In view of the fact this was on a straight I was doubting how much the new rear tyres "coating" had to play in it.
Any ideas? Is it possible that the front and rear tyres are "mismatched" in that the fronts dont appear to be a very sports car based tyre looking at the tread pattern. I am truly
and after spending £2k on the chim in the last few months am loathe to throw yet more wonga at the car at the moment but saturdays drive really wasnt pleasant and that "seat of the pants" moment was too frequent by far.
Ah yes, let me just lift my veil of red mist and I can actually see what you wrote in the initial post.
Curious.
Do the Toyo's have a stiffer sidewall than the Bridgestones?
If so the suspension could now be a little over hard because the take up in the sidewall would be less if they are stiffer. Which could lead to a more unsettled ride because the tyre is in contact with the road less...
Curious.
Do the Toyo's have a stiffer sidewall than the Bridgestones?
If so the suspension could now be a little over hard because the take up in the sidewall would be less if they are stiffer. Which could lead to a more unsettled ride because the tyre is in contact with the road less...
Did I tell you about how my Bridgestone S03s needed curing?
If you have a bible read it up in the tyre section.
Basically it means heating the tyres up and then allowing them to cool a couple of times.
20 mins of hard driving is good enough to heat them up. The Corhampton loop is just about right, good roads too.
I did it a couple of times and then left the car for the rest of the day. It made all the difference.
Thats not to say the curing thing is not a myth, I may have just scrubbed off the shiny bits.
I hope your tyres last longer than mine. Im gonna be lucky to get 6000 miles for all 4.
O/T: Goodwood certainly provded the S03s were good and Im now wondering if I will go for my Toyo compaision since Im already happy.
If you have a bible read it up in the tyre section.
Basically it means heating the tyres up and then allowing them to cool a couple of times.
20 mins of hard driving is good enough to heat them up. The Corhampton loop is just about right, good roads too.
I did it a couple of times and then left the car for the rest of the day. It made all the difference.
Thats not to say the curing thing is not a myth, I may have just scrubbed off the shiny bits.
I hope your tyres last longer than mine. Im gonna be lucky to get 6000 miles for all 4.
O/T: Goodwood certainly provded the S03s were good and Im now wondering if I will go for my Toyo compaision since Im already happy.
plotloss said:
Do the Toyo's have a stiffer sidewall than the Bridgestones?
If so the suspension could now be a little over hard because the take up in the sidewall would be less if they are stiffer. Which could lead to a more unsettled ride because the tyre is in contact with the road less...
hmm, might be a good point. Anyone else care to comment on sidewall stiffness of the 2 tyres? Wanted to get the alignment checked too but they couldnt do that on a TVR and only suggested nelson mandellaDustyC said:
Did I tell you about how my Bridgestone S03s needed curing?
If you have a bible read it up in the tyre section.
Basically it means heating the tyres up and then allowing them to cool a couple of times.
20 mins of hard driving is good enough to heat them up. The Corhampton loop is just about right, good roads too.
I did it a couple of times and then left the car for the rest of the day. It made all the difference.
Thats not to say the curing thing is not a myth, I may have just scrubbed off the shiny bits.
I hope your tyres last longer than mine. Im gonna be lucky to get 6000 miles for all 4.
O/T: Goodwood certainly provded the S03s were good and Im now wondering if I will go for my Toyo compaision since Im already happy.
problem is mate I wouldnt want to try and drive it hard as it is. It scared the sh*t out of me!
trefor said:
From experience, SO3s are significantly harder on the sidewall than Toyos. My std Chim handled very well on Toyos. My guess is that you need to tune the suspension to these softer running tyres.
cheers for that. I wonder whether there is a problem with the compatibility with the front tyres with harder sidewalls too.
Shnozz, do you want to borrow my S02 fronts.
They have a soft sidewall like the Toyos.
If you can get the tyre bay to fit them you are welcome to use them for a trial.
You wont be wanting them for keeps though as they have only just enough for a trackday. (Which is why I've got them!)
They have a soft sidewall like the Toyos.
If you can get the tyre bay to fit them you are welcome to use them for a trial.
You wont be wanting them for keeps though as they have only just enough for a trackday. (Which is why I've got them!)
Must admit (whisper it) I'm still not that impressed with my chim's handling, i'm on the avo shocks / springs. pbrettle has the same setup and we have got through many a pint trying to talk our cars into handling better!
I try to make sure the front and rear tyres match, but I shouldn't have thought that alone would make as much difference as you describe, shouldn't be noticeable in a straight line, i'd have thought.
As you know, the tyre forms part of the spring / damper equation and my best guess would be you have been unlucky enough to find tyres that are mismatched with your existing settings.
If it was my car and i was experimenting, I would try leaving the front alone but making the rear damping noticeably harder - 8 clicks or something. If that is too hard but it cures the twitchyness (seems you've found the legendary Twitchy Ness monster) then wind it back one or two clicks a day untill you are happy with the comprimise.
All IMHO - or just ask someone who knows what they are talking about, of course!
I try to make sure the front and rear tyres match, but I shouldn't have thought that alone would make as much difference as you describe, shouldn't be noticeable in a straight line, i'd have thought.
As you know, the tyre forms part of the spring / damper equation and my best guess would be you have been unlucky enough to find tyres that are mismatched with your existing settings.
If it was my car and i was experimenting, I would try leaving the front alone but making the rear damping noticeably harder - 8 clicks or something. If that is too hard but it cures the twitchyness (seems you've found the legendary Twitchy Ness monster) then wind it back one or two clicks a day untill you are happy with the comprimise.
All IMHO - or just ask someone who knows what they are talking about, of course!
shnozz said:
......snippity.....
Since then I have changed the suspension for £1k's worth of specialist shocks and springs. Fully adjustable and had set them up fairly stiff but with enough movement for fast road use...........snip
Suggest you let the tyres "bed-in" as per bible.
In the mean time use the "specialist schocks" and soften the rear by 4-ish clicks. I think you'll like the difference.
Trev McM
This may be far too simplistic but... the Toyos are softer than Bridgstones and are brand new with 8mm of (bendy) tread. It may just be a combination of the above making it feel as though they are all over the place. Scrubbing the tyres in and losing a mm or 2 of tread (and just getting used to it) may be all that's needed. I hope so 
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