ZX7 tyre change

[elrond]

my rear tyre is just about shagged and I am running a set of dunlops.

If I want to change to something else (people seem to like the pilot powers?? unless there is something better for the 7?) is it advisable to change my front as well?

I will go and see Mick @ MTM if i have any money left over from fixing this thing after all the damage the theives have done

unrelated note - greenmeanie you've got almost the same model as me - what fuel do you run - i couldnt find a recommendation in my service manual?

[HemiDuty]

Just run BP Ultimate in it Elrond, that is the stuff for all sportsbikes. The Caltex Vortex stuff is ok too.

Changing the front with the rear is definitely advisable, but if short of a buck just ask Mick what will work with your front.

[greenmeanie]

I have shinko 003 ultra soft front/pilot race rear.....yes i go to mick ....have done 4 a long time! No complaints with that combo.......work a treat! ($370 pr fitted).

Fuel like hemi said....bp ultimate/caltex vortex etc.....pretty much any premium except shell !

[mrmina]

the best i found for the 7r is the mobil syenergy 8000

[MadKaw]

you may also want to try 180 instead of the 190. It will quicken the steering up a little.. The 7 didn't really need a 190 but it was fashionable at the time.... unlike Ponti's moustache..

[HemiDuty]

And the haircut, or lack thereof.

Yeah like Mr Kaw said, a 180 is worth trying too, as the 7 is a little slow to steer.

[elrond]

thanks for the advice guys

will let you know how it goes

[mrmina]

you may also want to try 180 instead of the 190. It will quicken the steering up a little.. The 7 didn't really need a 190 but it was fashionable at the time.... unlike Ponti's moustache..

is that all it effects, the steering and nothing else

[smek]

From what I understand, using a lower profile tyre will change the angle of the bike, causing it to slope more to the front. The same effect as dropping the triple clamps down the forks, or raising the rear.

This will put more weight on the front wheel and so any steering inputs will have more of an effect. Hence you get quicker steering.

It will also make the bike more unstable as smaller movements will have an effect on the travel of the bike. Though I doubt you'd notice this a lot.

[HemiDuty]

I think what Smek means is a higher profile tyre, which is what you get with a 180. Most 190s are a 50 profile, which means that the sidewall is 50 percent the cross section (or whatever) of the width, and with a 180 this number is 55. In effect this means that the tyre is 'sharper' and will turn quicker, as in it would take less effort to push it over. That is why with slicks they are usually a taller profile on the 190s, so that it steers quicker, and also is taller so has the geometric effect Smek mentioned.

[mrmina]

now we're talking. i understand.

[faz]

Tyres like the bridgestone bt-002's come with a 190/55 rear. Quicken the steering on the 7 and these are bloody good tyres if your looking for something for track and scratching only.

[mrmina]

i've worked it out.

if u fit a standard 190 on the zx7r, it has a wall height of 95mm. By fitting a 180 the wall height is 99mm. So u have effectively raised the height at the back by 4mm.

[HemiDuty]

Yeah but you have to watch the figures a bit Mina. They can be a little off, it is the reason I wish they would use the racing tyre method for road tyres, i.e. instead of a profile measurement you get the total height. For instance my current slicks are 120/600 and 190/645.

The 190/55 Faz suggested is a good thing I reckon.

But either way getting a 7 to tip in a bit faster is a good thing.

[redzedx7r]

betta late than never
on the 190 vs 180 make sure it is the right rim width because later models post 2000 (i think?) ran wider oem rim to fit 190's, if you put a 180 on that rim you flatten out the profile and actually slow the steering down.