TYRE PRESSURE DROPPING TO QUICKLY ?

[jamesd1981]

Hi folks

Seeking some tyre advice, I have just mot my bike with no real problems had couple of advisories including new front tyre.

However i am wondering if both need replaced, I usually pressure my tyres to 34f and 36r, but within a couple days bike starts to feel heavy and when i go back to top up both tyres have dropped into mid or low 20s.

Should they be loosing that much pressure so quickly ?

Also how do i go about choosing a good tyre and get the best performance.

Current tyres are, 120/70/17/58 front and 150/70/17/69 rear, however manual states correct rear size is 160/70/17/69

Are these the best sizes for my bike a suzuki gsx 600f 1994

If not I am able to change to other sizes for better performance.

Thanks james

Edited November 23, 2012 by jamesd1981

[Guest Hodgy]

They shouldn't loose pressure so quick, leaky valve perhaps?

I'd stick to the size recommended in the manual, I use Michelin Pilot Roads, great tyres and last ages

Edited November 23, 2012 by Hodgy

[jamesd1981]

Thanks hodgy, I have never bought a motorcycle tyre before, If i get 2 new tyres will they come with valves ?

[Guest Hodgy]

Yep always best to get the fitter to put new valves in when they fit new tyres, they normally do anyway

[jamesd1981]

I have just been browsing tyres on the black circles website.

As i posted that rear is different to the size advised in the manual, on checking prices the cheapest 160 tyre is over £100, but 150 size tyre start from £50 odd.

I suppose that why the owner before me has put that size on, will the difference really have a big impact on performance ?

[Guest Hodgy]

Sorry, no idea what difference putting a narrower tyre on would make

[mattycoops43]

As a GENERAL rule (don't flame me) Bikes are designed to handle right with the size tyre they left the factory with. You can change them a bit, but you need to either get proper advice or know what you are doing, I would not just go changing size for the price.

[megawatt]

Unusual for any properly fitted tyre to lose ANY pressure, unless it goea from very hot to very cold. Try a different tyre fitter, change the valves and check for leaks. You may have leaky WHEELS!!!

[jamesd1981]

Thanks all for the advice, new tyres and new valves it is.

[Stu]

get the fitter to clean up the bead seating on the wheels before he fits the new ones

stick to the correct size for your bike as you may find that with a narrower tyre you will be at the edge quicker and think you have more lean and end up on your arse because there will be no tyre left!!

[Stu]

by the way your tyre size is

Front: 110/80/17

Rear: 140/80/17

you sure that manual is right?

[mattycoops43]

Depends on year, a 96-2000 is showing as 120/150 as being correct anyway. It could just be a wrong year manual, or tyres for wrong year bike fitted.

What year bike is it?

[Stu]

it says 1994 above matty

[mattycoops43]

Thank you sensei!

SO, The previous owner has fitted tyres from the wrong year then!

[jamesd1981]

Thanks matty and stu, yes the tyres on the bike just now must have been put on by a previous owner.

My bike is a 94 model

So is, Front: 110/80/17 Rear: 140/80/17, the correct size for my model ?

[Guest]

140 is the right size rear for your year, as your new to buying tyres just go to your local motorcycle tyre shop and ask what they think, I know most places do it a little bit cheaper if you buy a pair, I think that's what you said you were planing, they should include a valve and balance in the price, and you would get the fitting cheaper if you took in loose wheels, ie off the bike, hope this helps and don't forget to take it easy for about the first 100 miles as you need to scrub them in, you don't want to fall off.

[jamesd1981]

I had been looking at online at black circles.com for tyres at the prices seemed really good for top brands, would say it is better to take the bike to a local dealer instead ?

Could i ask as it seems the tyres currently on the bike are too big at both ends, should i expect any big difference in the way the bike handles when i put the smaller correct tyres on ?

Thanks again to everyone for the help

[Stu]

when you buy loose tyres you will have to pay to have them fitted most places now charge a little more but usually includes fitting and works out cheaper

its even cheaper if you can take the wheels off and take them in

[Mrbarry]

Camskill and black circles have a free delivery as fitting service, they use places like quick fit but you pay black circles or camskill direct. I have used them before and used that service.

Changing the width of the rubber on a wheel caused it to be stretched or bulge, this can be desirable but only if its planned! On a bike it's even more complex tho.

[Stu]

i wouldnt let kwik fit near any of my rims!! not even on the car! they are full of monkeys!

[Guest]

Stick to the size on there as your used to them, I had a gsx750f with those size tyres on it, handled like a dream.

[mattycoops43]

Find out the sizes of the rims on earlier and later models, if they have the same size rims (width) then I don't see how it is different from a later model then?

[jamesd1981]

I have been browsing tyres and am looking for some advice if these two tyres will match well ?

front tyre

http://ssl.delti.com/cgi-bin/rshop.pl?d ... 1110&m_s=1

rear tyre

http://ssl.delti.com/cgi-bin/rshop.pl?d ... 1110&m_s=1

[Mrbarry]

Agreed quick fit is full of idiots in the main, they use hundreds of companies tho that was just an example.

And if you like the way it handles with those sizes that's it! There is no right and wrong it depends on riding style, application, terrain all sorts.

[jamesd1981]

I did call a local shop and they said they would never recommend changing sizes and told me the previous owner probably put those sizes on the bike because they are more common and a lot cheaper.

Can anyone tell me if the two tyres, I have linked above will match ? The tread pattern on the rear tyre looks very different to the front but i am unsure if that is just because the rear needs thicker tread.