Tyre scrubbing on the inside
Tyre scrubbing on the inside
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Discussion

fr0zent0ast

Original Poster:

697 posts

171 months

Sunday 23rd February 2014
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I needed to replace the front tyres as the inside of them had been scrubbed down to not much at all, but instead of this I decided to buy some RL7's and get new tyres for those instead.

They arrived and I put them on today, but they are also scrubbed to not much on the inside. I assumed the original ones had gone because of tracking, but the RL's have come off another car and have the same scrub.

Is this a common thing? Is there something I can do to stop this? I will get the 2 fronts changed next weekend and have the tracking done but wondered if there is something else to look at, or just one of those things?

Also, what PSI do you all run? The tyres have a max 51PSI but I put 45 in the rears and 40 in the fronts.......


Quinny

15,873 posts

290 months

Sunday 23rd February 2014
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I don't have a cerb, but I'd guess those pressures are way to high....yes

fr0zent0ast

Original Poster:

697 posts

171 months

Sunday 23rd February 2014
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Quinny said:
I don't have a cerb, but I'd guess those pressures are way to high....yes
Yes, I did wonder if it was too high.....

Anyone with 17" RL's that can give a bit of guidance?

scotty_d

6,795 posts

218 months

Sunday 23rd February 2014
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That's why the tyres might be scrubbing 45psi!!!

No it will be a scary death ride in that at this time of year!

I run 24/25 psi all round and most others do as well. Some even softer.

robsco

7,875 posts

200 months

Sunday 23rd February 2014
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24psi all round on RL7s is how I run mine. 40 is much, much too high.

Gazzab

21,573 posts

306 months

Sunday 23rd February 2014
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Sorry but how can you drive a car with such tyre pressures! Wow. Totally amazed you can't feel the car handling like a pig and trying to kill you!

K4TRV

1,819 posts

276 months

Sunday 23rd February 2014
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fr0zent0ast said:
........snippity............... I assumed the original ones had gone because of tracking, but the RL's have come off another car and have the same scrub.

................. but wondered if there is something else to look at, or just one of those things?........................... I put 45 in the rears and 40 in the fronts.......snip!!
Firstly, it would be most unusual that a rim change to RL 7s will change any geometry...............if your geo is out, then it out!!

As well as geo you also need to see what Camber and Castor settings the suspension is set for? I do expect you have too much neg camber - that's down to probably worn bushes or incorrect settings (if you Sprint/Speed hill climb you "do" need slightly more neg camber and you will scub the inside of the tyres??)

Get a TVR Indy to set it up??

Tyre pressure.....nothing more than 24 to 26 f/r max on any post 1990 TVR - check a handbook or read the Cerbera Wikkis??

HTHs

T

jamieduff1981

8,092 posts

164 months

Sunday 23rd February 2014
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You'll have a heck of a skittish car at those pressures. As above, I run 24psi all round. It's a very light car smile

Boatbuoy

1,972 posts

186 months

Sunday 23rd February 2014
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24 psi all round here too.

Jhonno

6,430 posts

165 months

Monday 24th February 2014
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scotty_d said:
That's why the tyres might be scrubbing 45psi!!!

No it will be a scary death ride in that at this time of year!

I run 24/25 psi all round and most others do as well. Some even softer.
High pressure wears the middle of the tyre, low the shoulders..

Sounds like your geo is out. I run 25psi all round in my Cerb.

QBee

22,172 posts

168 months

Monday 24th February 2014
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Get the car down to a TVR specialist for the Geo. Avoid the likes of Kwikfit. You must be reasonably close to Str8six. A TVR specialist will know the correct settings. My Chimaera tried to throw me into the river when i first had it. One four-wheel geo later and it was a joy to drive. That and the tyre pressures, and you will not believe what a different car you have. driving

gruffalo

8,100 posts

250 months

Monday 24th February 2014
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As QBee has said I would get the care along to STR8SIX and get it set up properly, they can certainly do that for you. They are an excellent garage who look after miy Cerb, in fact mine is there today having her 1000 mile service.

Tyre pressures are, as pretty much every one has said, sky high so drop them down.

Cerbs do wear the inside edge of the front tyres more quickly than anywhere else due to the camber settings but it depends as to the extent of wear you are seeing.

ukkid35

6,386 posts

197 months

Monday 24th February 2014
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I often put my tyres at 40psi, but only when the car is left standing over winter.

knight

5,234 posts

303 months

Monday 24th February 2014
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The tyres on the original wheels were on the car when I bought it in 2008 but I only ran it on them after selling the 18s in august last year. I had heard that the insides wear quicker on a Cerb, and the 18s did the same so I had the tyres swapped over to even out the wear.
And I only put about 24psi in the tyres too.

jamieduff1981

8,092 posts

164 months

Monday 24th February 2014
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When I bought mine a year ago it was at 22psi on the fronts (Goodyear GSD3s) and they were bald on both shoulders. I've got more lateral grip at the front than the rear but it seems to lock up the fronts under braking more readily than the rears. It could probably do with a decent set up but I can't see what use any additional negative camber on the front would do me...

Sevenman

762 posts

216 months

Monday 24th February 2014
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jamieduff1981 said:
but it seems to lock up the fronts under braking more readily than the rears.
That is how you want it.

Ideally you want the fronts to lock just before the rears lock, that keeps it stable.

Having rears locking first is bad and has been causing me headaches and expense with my Tamora.

Vee8ight

734 posts

163 months

Monday 24th February 2014
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I run 29/28 F/R on my Cerb. FYI a Sag runs 28 all round and a Cerb is just a tad heavier at the front. IMO 24 psi is too low

K4TRV

1,819 posts

276 months

Monday 24th February 2014
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Vee8ight said:
snippity........ FYI a Sag runs 28 all round..........................snip........
Not according to Mr Varley's "Bible" - as everyone else has "suggested" 24 psi all round for a Sag which would also be appropriate for Cerb...................AIMVHO

T