150 70 17 tyre.

[lh25]

Hi all am looking to buy one of these rear size tyres but was wondering if its and better than a 160 60 17 in price or usability. I mean that i dont use all the tread on the rear i got about 12mm left of unused tyre on the rear so maybe i could use a 150 70 17
cheers

[yorkie_chris]

Lean over more :-P

[Nick_69]

I wld still get a 160 as u wil start to lean over more anyway

[lh25]

ok i should have said the front has no unused tyre on it but the back just seems to fold round so that it pretty much vertical as if its too wide for the rim i think the bike would have to be on the floor to use it all up. the tyres are pilot road 2ct im wondering if its a fault with the tyre or its wrongly sized up ??????

[Berlin]

Thats usual for the PR2 before its put on a smaller rim. The Rear on an Sv is also pinched so you're never going to get to the edge of a PR2 rear.

Try a 150 and let us know how it is :)

C

[punyXpress]

Either that or get the widest you can & when the middle is bald cut it out & stick the two halves together - double ( or more ) the mileage - result!
ps : don't blame me if it ends in tears.

[Ghost_Rider]

if you go down to a 150 section from a 160 then the tyre wont have as much curve, making the turn in responce slightly slower not by alot but when i went from a 130 to a 140 rear tyre, it did make a fair bit of difference on turn it responce, cornering speed and lean angle were both incresed, never got down a tyre size but i would belive that if you did your turn in responce, cornering speed and lean angle would all decrese slightly, up to you but if i were you i would go up a size and certainly not down, but its up to you let me know if you notice a difference or not :)

[yorkie_chris]

Bear in mind as well when you switch to any new tyre it feels to turn in very well, as your previous tyre may have squared off.

[Berlin]

if you go down to a 150 section from a 160 then the tyre wont have as much curve, making the turn in responce slightly slower not by alot but when i went from a 130 to a 140 rear tyre, it did make a fair bit of difference on turn it responce, cornering speed and lean angle were both incresed, never got down a tyre size but i would belive that if you did your turn in responce, cornering speed and lean angle would all decrese slightly, up to you but if i were you i would go up a size and certainly not down, but its up to you let me know if you notice a difference or not :)

Interesting. The general concensus of opinion is the reverse of this. The wider the tyre the slower the turn in.

Which bike was this on?

[Ghost_Rider]

Interesting. The general concensus of opinion is the reverse of this. The wider the tyre the slower the turn in.

Which bike was this on?

i realise what i am saying is the reverse but i had an extremely indepth convo with my boss (a motocycle mechanic for the past 30 years) about tyres and what effects changing the size of your tyre will make to handling. i understand may not have given the best explanation but i do know what i am going on about (i am not the best person at decribing things)

it was on my old yamaha yzf-r 125 i know its olny a lil engine but the general effects of changing the tyre size dont change between bikes

to be honest my tyres were pretty evenly warn but i do realise changing they tyre does make quite a difference to turn in responce

[Berlin]

Ok, thanks for the clarification. You may find tht when you get up the sizes the opposite happens and the larger the tyre the slower the steering.

C

[sunshine]

Bear in mind as well when you switch to any new tyre it feels to turn in very well, as your previous tyre may have squared off.

But squared off rears make you drift as you come off the square and onto the round part, feels amazing going round corners getting it a bit sideways.

As for running out of front tyre, counter steering should make up for this.

[Berlin]

As for running out of front tyre, counter steering should make up for this.

How so?

C

[sunshine]

dont know on my old tyres i ran out of tyre was told counter steering helps and the rear lines got smaller and i didnt lose the front, so it must work, or thats my theory anyway :D

[Berlin]

Well go and slap the bloke who told you that :)

Once you're at the edge of the front tyre you're at the edge of the front tyre. the only thing that will allow you to lean further is reducing the pressure in it so the footprint is larger or increasing the load on it so it squishes, achieving the same effect (but not too much more load or it'll slide).

At full lean countersteering (moving the bars) will cause the bike to rise or fall. if you are at the edge and it falls, you fall too :)

At full lean (holding a constant radius) you are actually turning the front tyre fractionally away from the road (by pushing the inside bar away). When you countersteer to get the bike to rise back up (pushing the outer bar away), you are turning the tyre down, into the road. Too much of either reduces the size of the front footprint of the tyre and will end up with you seeing how effective your crash bungs are.

Clearer?

C

[sunshine]

that makes alot of sense, i guessed something like that is nearer to true, but still like to have the bike on its limit.

[Sly]

Thats usual for the PR2 before its put on a smaller rim. The Rear on an Sv is also pinched so you're never going to get to the edge of a PR2 rear.
C

That's interesting... I thought it was just me being a pussy ;) Has nobody worn the lettering off the edge of a PR2 rear?

With my admittedly threadbare PR2s it is always the front that starts to get loose first, unless I've hit the throttle too enthusiastically after the apex.

I thought the stock rear size was designed to provide a suitable footprint to handle the amount of power the particular model delivers when powering out of corners, so a 1000cc IL4 would need a wider tyre and a less powerful bike a narrower one.
I'm not claiming to be any kind of expert, just interested to hear from the more knowledgeable. I've not thought much about the issue before now, but assumed that tyre sizes were set to allow full power to be applied out of corners on dry road to pick the bike up naturally without counter-steer. - The only exception being hard-tails where oversize rears are necessary for tail-bone and spine protection :smt047.