Road Tyre Pressures and tyre problems

[G]

Not sure if anyone can help.

I have some standard Dunlop D218 tyres on my cbr. Now, in the book it says the tyre pressures should be set at 42psi rear and 36psi front, which to me after the sv seems odd (but i dont know anything really).

I cant find anything on the internet that can confirm this is right or what other people recommend.

I checked the pressures last night and they have been set WAY off what the book says by the dealer so I dont know who is right.

Last night when cornering relatively quickly my rear tyre had a MASSIVE slide, there was nothing on the road and the tyres now have 250miles on them with very little left unscrubbed on the edges to cause the slip, could crap tyre pressures cause a tyre slip like that?

I assume the tyres are reasonable sports tyres as they are fitted on all cbr's and the likes of the kawasaki zx10.

Any help on this would be appreciated as I know theres some fairly knowlegable tyre type people on here.

[fizzwheel]

If it were me I'd set them back to what the book says and then adjust to suit your riding style from there.

Pressures your book says are the same as whats recommended on my GSXR. I know its a different bike but similar in terms of what it is and tyre sizes I'd imagine.

Just out of interest what were the pressures set to when you checked them ?

[Mogs]

Try here for some info,

http://www.dunlopmotorcycle.co.uk/tyres/search/bike/?manufacturer=Honda&model=CBR+900+RR+FireBlade+2002-2003

[jambo]

As with Fizz, I run 36/42 on my 2001 ZX6R. Put them to that and work from there.

[Luckypants]

My VFR is 36F/42R (120/60 and 180/50) recommended pressures. I use these without any problem.

[Skip]

My Z750 is 36F/42R seems to be the standard pressures for a 120/70 and a 180/55

[G]

I checked this morning and the front was 31.4psi whilst the rear was 38.6psi.

Much less than recommended in the book.

At the moment they dont inspire any confidence and I'm wondering if its the pressure in the tyres or the tyre themselves just being crap, at the moment I have less confidence with the rear than with the rear D220 I had on the SV.

[G]

Try here for some info,

http://www.dunlopmotorcycle.co.uk/tyres/search/bike/?manufacturer=Honda&model=CBR+900+RR+FireBlade+2002-2003

My tyres dont even seem to be listed on there unless I have read them wrong off the tyre wall which is possible.

But from reading everyone else posts I think my pressure are massively out so will readjust them and see how its goes from there.

These are what I have on mine I think

http://www.dunlopmotorcycle.co.uk/tyres/ranges/roadRadial/d218/

Edit: Just reading a news article and it says

'The OE specific Dunlop D218 tires actually fit into both of Honda's design goals for the bike. First, they are lighter than the D208 tires on the 04 model. Lighter tires make a big difference for a couple of reasons. The weight has to be accelerated twice: as part of the bike's overall weight and part of the rotational mass of the wheels. So, all things staying equal, lighter tires would help a bike accelerate, stop and turn more quickly. Throw in the D218's formidable grip and wear characteristics, and this update to the 600RR sounds pretty good.'

So its not the tyre grip levels thats giving me issues unless they arnt getting heated enough which I suppose is possible with me not taking the bike above 96mph/7.5krpm

[Stu]

I love 36/42* as well, but unfortunately for you I don't think your actual pressures were that far off to make a huge difference. I would just put them up to 36/42 and then it's going to take a lot of riding for you to learn your confidence in what they will do.

*D208 on my ZX7R & Conti road attack on my SV

[G]

I would just put them up to 36/42 and then it's going to take a lot of riding for you to learn your confidence in what they will do.


I'll do this i think........after doing some reading it must just be me not getting the tyres upto temperature :(.

[neio79]

had mine lowered from 42 to 34, handles better. lower pressure increases the tyre contact patch, adn they warm quicker as well.

42 IMO is to much, and causes the center to wear qucker as well, why do you think the tyre presures are lowered for the track.

[Luckypants]

why do you think the tyre presures are lowered for the track.

Because tyres get a lot hotter on the track (due to constant abuse) and so the air inside expands more, thus increasing the air pressure more and so reaching the same operating pressure from a lower start pressure.

[neio79]

Because tyres get a lot hotter on the track (due to constant abuse) and so the air inside expands more, thus increasing the air pressure more and so reaching the same operating pressure from a lower start pressure.

very true. But from prsonal experiance (dropping my own pressures on BT-015's) They handle better, have a biger contact patch hence more wear across the tyre rather than just in the centre, and you dont feel the bumps as much as the tyre is soaking some of the pressure not the suspension taking it al.

[muffles]

Just try a load of different pressures and see how it feels for you!

[DMC]

Just to be different, recommended on the GSXR K7 with standard BT14's is 36F 36R.