This was resolved, as far as I am concerned, recently. I changed to SO-2s as a result of an off-road excursion (don't ask me about this!) which gashed my original rear SO-1s. Thankfully, this and a slightly out of round wheel were the only damage. TVRM replaced the wheel and all 4 tyres for me, as SO-1s were no longer available. They also did the alignment and of course when I got it back, did not feel right. Allowing for a bit of running in, things did not improve and I took it to my regular computerised 4-weel alignment shop (Hunter Equipment). Sure enough everything measured out of spec. In fact, both my LHS wheels were toe out! Having had enough, I took the liberty (in violation of warranty and other factory warnings!) of having it re-aligned there. The car was a revelation after that. The steering feel snapped into focus and the handling was much sharper and more predictable. I told the factory this and they just shrugged it off!
My take from this? I would not trust the factory's or dealer's alignment skills or tools. I trust my regular alignment shop because I know they regularly calibrate the computerised set-up and the inherent skill of the mechanic doing it. He had no experience with TVRs (nobody here does) but does Ferrari's and Porsche's. However, I told him how to do it on the Griff (having seen it done at TVRM) and he learnt very quickly. One thing to note is that camber adjustments necessitate wheel removal. This has to be repeated many times per wheel to get right, as it is also very sensitive (small movement = many degrees). This means it takes time and therefore high labour charges. Also, it brings to mind that this is really only possible in a computerized alignment set-up, since the car can be raised on a hoist. The manual set-up jig as used by the factory, would have required re-setting of the instruments each time, and I doubt if even an enthusiastic mechanic would do this willingly! So, a reliable specialist garage with computerised 4-wheel alignment would seem the best bet.
As another point of reference, I had the same experience with
an MX5. The dealer could never get it right whereas this specialist
shop could.
Kenny Heng
Oct 97
Kenny,
Thanks for that. Very interesting, especially as my TVR dealer
has warned me against letting anyone other than a TVR dealer get
their hands on my steering geometry! The same dealer has been
working on some mods of his own to stop the suspension components
slopping about, but I think he's given the idea up as being too
expensive to put into production. There are two other problems
as I understand it, and I must admit I haven't had a really good
look at the suspension to confirm this:
1. I believe the top wishbone bushes have some free movement on them which means the wishbones aren't located securely fore and aft. I think there is about 3mm of movement on each wheel. Most of the time they will settle into one position and stay there( possibly resulting in the wheelbase on one side being slightly less than the other), but under very heavy braking or hard corning the bushes can move which results in the castor angle changing in mid-manoever.
2. The camber angle is adjusted by pinch bolts that go through slotted holes (is that right?), so the camber angle depends entirely on friction to keep it where the mechanic has set it. In my case it seems not to have worked and I ended up with huge negative camber shortly after the service. Probably less noticeable to the driver on a Chimaera with higher profile tyres and softer suspension (well, that's my excuse) but enough to scrub a couple of mm off the inside edges of the tyres.
I guess if you wanted precision suspension components you wouldn't fabricate them out of welded tube, but at TVR production volumes you don't have much choice. I wonder whether the Tuscan boys have these problems. Probably they've solved the first with nylatron bushes which wouldn't be very nice on a road car, and I'd imagine the camber adjustment on a race car is a bit more robust.
One solution to the camber problem that occurs to me is to put
a whacking great washer under the bolt then drill through when
the adjustment's spot on and bash a dowel in. No doubt you'd
have to weld the hole up and do it again every time the bushes
were replaced, but it might work. Not sure how often you could
get away with this before there was nothing but re-drilled weld
holding the wheels on, though!
Peter Beech
Internet Mailing List Aug 96
. . . I've just been through the same loop for my S2, with local
dealers saying RE71s are out of stock. General consensus was that
short of going to S01, only Yokis have the grip but don't last
long. RE71 availability is difficult but Elite do them mail order,
next day delivery, and your local fitter will fit and balance
for £5.50. This worked out cheaper than most alternatives
and got me "proper" tyres.
Richard Eggleston
Internet Mailing List Aug 96
I thought that S01 and Expedia were one and the same, so there
must be some confusion here. Don't rely on your TVR dealer as
they are notoriously expensive for tyres (like any marque's main
dealer) . . . Other makes are likely to last longer, but may have
less grip. You can certainly get Pirelli P-Zeros and P6000s in
the right size.
Steve Powell
Internet Mailing List Aug 96
I recently got a set of rear tyres for my Griff, Bridgestone Expedia
SO1/225s. I shopped around and the best prices were from Elite
and this was matched by TVR Brundle . . . The 225s do me OK. I
know someone who uprated theirs to 235s - but they are quite mad.
Steve Marriott
Internet Mailing List Aug 96
The Expedia and the S01 are the same tyre. I bought a full set
back in January for a shade under £600 (£138 front,
£150 rear, including VAT, valves and balancing), and that's
the cheapest I could find. I did think about getting a different
make, but unfortunately nobody else seems to make the front tyre
at a cheap enough rate. It seems like the 205/50x15 is a bit of
an oddity. The only other tyre I've seen on a Griff was the Expedia
S02, when I did a sprint at Three Sisters a few months back.
Sean J. Lennon
Mar 97
After wearing out the centres of his Griff's back tyres for the
nth time, Jeremy Pace took his tyre shop's advice to try some
Yokohama A411s as fitted to the Lexus. The problem with the Bridgestones
is apparently that the tread area is not very rigid and it bulges
at high speed, resulting in uneven wear across the tread width,
especially if you spend a lot of time going fast on straight roads
rather than sideways round twisty bits as god intended.
The Yokos have reinforced treads so are supposed not to suffer from this problem. Jeremy says that the ride is also less harsh and the back end skips around less. The Yokos are in plentiful supply at the moment because Lexus owners can opt for seventeen inch rear wheels and the standard sixteen inch tyres are simply returned by the dealers, to be flogged off by Yokohama at about £110 a throw. No report on how well they wear, but Jeremy promised to report back.
Internet Mailing List Feb 97
I've heard this also, from memory the conclusion was that if it
were used as a "get you home" solution (or better still
get you to the tyre depot) it was OK. The tyre should then be
washed out and a proper repair made. Personally I struggle to
picture the Quickfit fitters washing tyres to make the repair.
"Sorry mate it's knackered, you'll need a new one" seems
more likely.
Mike Jennings