I've switched to NON-RFTs on the rear and..

[sk93]

well.. the car seems to squirm quite a bit when giving the beans.

I didn't opt for a massively expensive set of tyres, as I wasn't sure if I'd be keeping the non-rfts, and didn't want an expensive set just gathering dust in the garage.
But it is a very noticeable feeling and has actually got me thinking the backend was starting to step out a few times coming out of corners, when it wasn't.

Is this "normal" and just a feeling I'm going to have to get used to if I want to stay on non-rtfs?

 

[sideshowbob]

I dont get that feeling at all. My rear end feels much more planted than with the runflats.
What tyres are you using? and what pressure are you inflating them to?

 

[sk93]

Vredestein Ultrac Sessanta's running at 35psi.


It really is a horrible feeling - one that is solved immediately if I switch back to the RFTS at the same pressure

 

[PawnSacrifice]

Mine felt like that for a while... Goodyear Eagle F1s felt a little squirmy for a few hundred miles, the Vredsteins took a lot longer, can can still feel a little odd now - although they were fun on the Kent Sussex meet a few weeks back

Am sure they just need a monster scrubbing in session, I hear the drive to the Lake District is as good a route as any

 

[sk93]

hmm. ok.

I'm going into the garage this avo to see if we can try a different brand, just to see if it's a common feeling across all non-rfts that I'm just not used to feeling in the Zed.

If it's the same, I'll probably keep them for the lakes run and see how we go.

Tbh tho, if it still feels the same, I'll be going back to RFTs, as they felt much more solid and provided accurate feedback about what the rear was doing (imo )

 

[easty027]

Since i got rid of my run-shi*s i have had so much more grip both in the dry & wet !

 

[PawnSacrifice]

Vreds take a little getting used to, and they do certainly grip. Am running mine at 33 / 36 now which helped. There is an odd feeling to them though. My Goodyear Eagle F1s were immense, loved them. But there was 1 month + wait for the fronts when I needed them.

One thing I would say with the Vreds, although they feel a little odd they kept everything in check on my return from Goodwood and there were a couple bends I admit I went into a little more enthusiastically that I would have liked. The grip is definitely there - Andy runs them and you've seen what he gets up to :wink:

 

[sideshowbob]

Vredestein Ultrac Sessanta's running at 35psi.


It really is a horrible feeling - one that is solved immediately if I switch back to the RFTS at the same pressure

Thats exactly what tyre i run but at 33psi. As already mentioned they probably just need a really good scrub in. Most tyres will feel horrible when brand new. I believe its the releasing agent they use in the tyre mold when making the tyre. Takes a while for it to wear off. I would just give it some time (and a few wheel spins :evil: ), and drive carefully in the meantime.

 

[dgm]

I might be reading your title and post wrongly but have you put the Vredesteins on the rear only?

 

[AlanJ]

PS2s no problems even when pushing it into and out of bends. Depends on driving style as well.

 

[SpaceCoyote]

I might be reading your title and post wrongly but have you put the Vredesteins on the rear only?

Hmm, I was wondering about this.

My rear tyres are getting ready and I was going to go for non-RFTs, but I presumed it would be unsafe not to do all four at the same time.

 

[PawnSacrifice]

I might be reading your title and post wrongly but have you put the Vredesteins on the rear only?

Hmm, I was wondering about this.

My rear tyres are getting ready and I was going to go for non-RFTs, but I presumed it would be unsafe not to do all four at the same time.

Some people run mixed front and back without issue. Is it inherently dangerous, I don't believe so. However, there is a view, that many no here share, that you want matched tyres all around, just in case of that moment where it would count. I guess the variables are 1) how hard do you really push the car and 2) how risk averse are you with this sort of thing?

I'm one that runs matched sets, but tyre fitters wouldn't tell you not to mix front and rear whereas they would about left and right, good ones anyway.

 

[SpaceCoyote]

Thank you for that, good to know.

 

[sk93]

I might be reading your title and post wrongly but have you put the Vredesteins on the rear only?

Hmm, I was wondering about this.

My rear tyres are getting ready and I was going to go for non-RFTs, but I presumed it would be unsafe not to do all four at the same time.

I am indeed running non-rfts on the rear and RFTs on the front.

I have never seen any solid evidence that mixing tyres on DIFFERENT axles as being a problem, as long as they're the same size and speed rating (and radial/non-radial)
Infact, Goodyear seems to say it only matters on the same axle: http://www.goodyeartires.com/faqs/Care.html#s6 ( and I'd reckon they'd know more about tyres than anyone on internet forums )


Replacing a single tyre isn't an issue either, as long as it's the same as the one you take off..

 

[IK.]

Scrub them in, as said. I hated my new tyres at first but they're now a few hundred miles in and I'm much happier.

 

[EdButler]

You shouldnt take judgement on any tyres under 500 miles or so as Pawn said. I received my car with RFT's on the front and FK-452's on the rear and i'd go so far as to say it was dangerous with the tramlining (fronts pulling everywhere, rears not wanting to follow).

Your pressures are a little high too... Sidewalls of RFT's are much stiffer needing more pressure fully stretch them. You should reduce them my 3-4psi from standard (32-33psi)

 

[sk93]

I've just had some Maxxis thingies fitted with reinforced sidewalls. I believe they're budget, as they were half the price, but the difference now is obvious - they feel much better through corners - still not "as good" as the RFTs felt, but we'll see.

Cheers Ed, I'll drop them down to 33 for the weekend and see how we get on.

 

[AlanJ]

Just something to consider....

Tyres from different manufactures have different co-efficients of friction – that point at which the tyre loses its grip (breakaway point). Softer compound greater grip but higher wear rate a vice versa. The breakaway point will depend on either the force acting on it to reduce speed (braking) or the lateral force when turning - degree of turn and speed will also impact (tight turn v high speed = increased probability of breakaway/slide). Of course road surface condition (construction, wet, dry etc) will also have an impact on the breakaway point.

Matching tyres on a vehicle across both front and rear axles gives each tyre the same co-efficient of friction and hence the breakaway point is generally maintained at each corner of the vehicle – this will of course vary as the tyres will wear at a different rate from font to rear (BMWs – rear wheels wear first) and across the axles with nearside often wearing at a greater rate due to road camber. Where tyres breakaway at different points in a slide this can induce a spin which can be difficult to control whereas a slide (front or rear wheel) can be corrected with appropriate driver input.

Mixing tyre brands and tread patters across the front and rear axle on everyday cars will, if the tyres are maintained to correct pressure and tread depth, generally not cause any issues under normal driving conditions. However it may become an issue for high performance vehicles where tread contact with the road surface becomes more critical at higher speeds both in a straight line and when cornering and the breakaway point is more critical in retaining control.

It’s an individual choice on mixing brands across axles BUT worth remembering that the only contact and vehicle has with the road is through the tyre profile of the tread pattern from the tyres. Go for the best you can afford.

YES ANOTHER QUIET DAY AT WORK

 

[peddy]

Wait... You're running cheapo non-RTFs on the rear, which haven't warn in and mixed with RFTs on the front and your complaining about handeling...?? well what do you expect?

ditch the RTFs in the front, ditch the cheapo tyres on the rear and get a set of decent non-RFTs. drive them for a few hundred miles and then see what you think. I'm sure you'll be happy with them.

 

[Mr Whippy]

Running a mix of RFT front and NEW non-rft rear will generate some odd sensations of different ends doing things differently.

I'm sure with them bedded in it'll feel better, and with the same all round better still

Dave