Using slick tyres, why not road legal?

Status
Not open for further replies.

Berties

Banned
Been thinking about this why aren't you allowed to use slick tyres when it's dry? More grip = safer.

Of course you have the problem with rain, but what if you don't drive when it's wet? Or if it starts to rain you pull over and change the wheels over to wet tyres? (say if you have a 4x4 and spare set of wheels with normal tyres in the back) Although unlikely, but why can't places say Texas where rainfall is non existant and Middle East use slicks? :confused:
 

FZR400RRSP

Banned
You can get road legal tyres that are damned close to being slicks, in the motorbike world.
But even if rain is a remote possibility, you might come across a burst drain/flooding etc.
And believe you me, those close to slick tyres have your arse cheeks clenching as you wobble through water.
So the law caters for safety rather than the last degree of grip.
Most people are nowhere near good enough to use the extra grip slicks would offer anyway.
Treaded tyres give them all the grip they need without having to worry about rain.
 

TRL

Banned
It's not only rain that can make a road wet, and not only water that makes a road less grippy. Also, slicks, as used in racing, need to be managed through a heat cycle properly and don't work at all until they're very warm. If you mean just normal road tyres but with no grooves, why? The increase in surface area would be minimal, and easily bettered by increasing tyre width by 5 or 10mm.

Tony
 

alexs2

Well-known Member
Been thinking about this why aren't you allowed to use slick tyres when it's dry? More grip = safer.

Of course you have the problem with rain, but what if you don't drive when it's wet? Or if it starts to rain you pull over and change the wheels over to wet tyres? (say if you have a 4x4 and spare set of wheels with normal tyres in the back) Although unlikely, but why can't places say Texas where rainfall is non existant and Middle East use slicks? :confused:

I find it hard to believe this isn't a joke.

If you've ever driven a car on cut slicks or trackday tyres(which are road legal)and then encountered either a greasy road or even a light bit of rain,then you'd understand why full slicks are really NOT a good idea.

And to suggest that you'd pull over when it rains,jack the thing up and change all 4 tyres?

As both the others have said,getting near the grip limits of a high performance road tyre like Michelin Supersport or similar,would tax the abilities of most of us,and would also be well in excess of the speed limit.

Put it another way....get someone to take you out on a track with one corner wet,and the car on slicks....make sure you have breakfast first.
 

paulk

Novice Member
You can get road legal tyres that are damned close to being slicks, in the motorbike world.
But even if rain is a remote possibility, you might come across a burst drain/flooding etc.
And believe you me, those close to slick tyres have your arse cheeks clenching as you wobble through water.
So the law caters for safety rather than the last degree of grip.
Most people are nowhere near good enough to use the extra grip slicks would offer anyway.
Treaded tyres give them all the grip they need without having to worry about rain.

My enduro bike has a spare set of supermoto wheels. These have road legal cut slicks on them. I've ridden it in cold and light rain and it's been ok - but that was getting caught out when it rained and not out of choice. I had intended to do a few trackdays which is why I went for a cut slick but decided it wouldn't be a good idea as the bike just doesnt (understandably with 450cc of low down power) have the legs on the circuits I would want to do.

Biggest issue with slicks is getting them upto temp (where they grip) and then maintaining that temp. You can do it on dry trackdays with tyre warmers and then consistent speed, but that would not be feasable on the road. Loose temps with slicks and you might aswell be on a surface of marbles.
 

qwerty321

Member
I find it hard to believe this isn't a joke.

If you've ever driven a car on cut slicks or trackday tyres(which are road legal)and then encountered either a greasy road or even a light bit of rain,then you'd understand why full slicks are really NOT a good idea.

And to suggest that you'd pull over when it rains,jack the thing up and change all 4 tyres?

As both the others have said,getting near the grip limits of a high performance road tyre like Michelin Supersport or similar,would tax the abilities of most of us,and would also be well in excess of the speed limit.

Put it another way....get someone to take you out on a track with one corner wet,and the car on slicks....make sure you have breakfast first.

You must not visit General Chat very often . . .
 

FZR400RRSP

Banned
My enduro bike has a spare set of supermoto wheels. These have road legal cut slicks on them. I've ridden it in cold and light rain and it's been ok - but that was getting caught out when it rained and not out of choice. I had intended to do a few trackdays which is why I went for a cut slick but decided it wouldn't be a good idea as the bike just doesnt (understandably with 450cc of low down power) have the legs on the circuits I would want to do.

Biggest issue with slicks is getting them upto temp (where they grip) and then maintaining that temp. You can do it on dry trackdays with tyre warmers and then consistent speed, but that would not be feasable on the road. Loose temps with slicks and you might aswell be on a surface of marbles.

I'd suggest you'd get better grip from a normal sports tyres, especially one designed for lower weight bikes.
I don't believe your bike has the weight or power to make a cut slick work properly.
Over my years of instructing at track days, I've seen people 'think' slicks/cut slicks are the way to go, when they really aren't.
 

Inked

Distinguished Member
FZR400RRSP said:
You can get road legal tyres that are damned close to being slicks, in the motorbike world.

paulk said:
Biggest issue with slicks is getting them upto temp (where they grip) and then maintaining that temp. You can do it on dry trackdays with tyre warmers and then consistent speed, but that would not be feasable on the road. Loose temps with slicks and you might aswell be on a surface of marbles.


Yep, I remember watching a mate on his GSXR600 at Tring roundabout taking the first corner too fast and low siding after thinking he would have plenty of grip with his super sticky almost slick tyres because he hadn't warmed them up with a few slower laps to get up to temp.
 

paulk

Novice Member
I'd suggest you'd get better grip from a normal sports tyres, especially one designed for lower weight bikes.
I don't believe your bike has the weight or power to make a cut slick work properly.

The cut slicks were bought specifically to do trackdays in supermoto guise, but being road legal were handy dual purpose. In use you are incorrect in assuming they won't work properly. They are excellent for track and also on the road in the right conditions.
Even when I've used them on the road and been 'caught out' with a shower of rain they have been ok with no dramas. I've had much worse issues (grip) with road legal enduro (knobbly) tyres.


I've seen people 'think' slicks/cut slicks are the way to go, when they really aren't.

I never used slicks or cut slicks with 'sportsbikes'. Never saw the need. I ran Dunlop GPs as drys, moving onto Supercorsas when Dunlop altered their race distribution. Ran three sets of wheels (drys/inters/wets) which was a pain but kept you out on track in all conditions and tought you how to change wheels very quickly! If I thought for one minute the cut slicks could not work properly on the bike I wouldn't use them. As it happens they are very good and suit the supermotos very different (compared with sportsbikes) riding and power characteristics.
 

FZR400RRSP

Banned
The cut slicks were bought specifically to do trackdays in supermoto guise,

That's fair enough, you've done it properly.
It's just that I've seen people rock up to trackdays with superbike slicks, thinking they'll be great.
Superbike slicks meant for lightweight superbikes, not roadbikes.
And meant to be ridden hard to keep in the right temperature zone.
They'll often think tyre-warmers make them invincible too.
Then scratch their heads as grip deteriorates as their less-than-superbike-pace makes the tyre cool.
I've been doing trackdays since before tyre warmers, and crashes then were early on a session.
Cold tyres.
Now crashes often happen at the end of a session, as their heated tyres cool off.
Personally, I still prefer good sports tyres and 2 laps of a warm up.
Old skool.:laugh:
 

Berties

Banned
Why do slicks need to get upto temp? You don't have to do that for normal road tyres. And road tyres have less rubber in contact with the road then slicks.
 

Andyh4324

Well-known Member
Why do slicks need to get upto temp? You don't have to do that for normal road tyres. And road tyres have less rubber in contact with the road then slicks.

Slicks are generally a different compound of rubber than other tyres.
 

FZR400RRSP

Banned
Why do slicks need to get upto temp? You don't have to do that for normal road tyres. And road tyres have less rubber in contact with the road then slicks.

Racing slicks are made of compounds that work in a very narrow temperature zone.
But they stick like hell when they're in that zone.
Road tyres are made to grip within a broad temperature zone.
 
Last edited:

Berties

Banned
Slicks are made of compounds that work in a very narrow temperature zone.
But they stick like hell when they're in that zone.
Road tyres are made to grip within a broad temperature zone.

then make slicks out of same rubber used for road tyres then?
 

FZR400RRSP

Banned
then make slicks out of same rubber used for road tyres then?

You could make road slicks that work in a broad temperature zone too.
But then the only advantage they would offer is slightly more rubber on the road, and no tread movement.
Tiny advantage not worth having.
You'd probably pick up punctures left, right and centre too.
 

alexs2

Well-known Member
then make slicks out of same rubber used for road tyres then?

You don't seem to be getting this....

The real issue is that a road tyre has to work SAFELY under ALL conditions,not just the isolated circumstances of a racetrack,with pits to change your tyres and run-off areas for when you make a mistake or run out of skill on the changing conditions of a damp or frankly wet day.

This is why slicks are NOT a good idea for road use,under any circumstances.

When you're busy enjoying the supposed grip levels of your slicks,on a nice dry day,and you encounter the aforementioned wet corner from a water leak or whatever,then you'll find yourself at best sliding off the road,or at worst into the oncoming traffic.

Slicks have virtually no water clearing abilities worth speaking of,and a large number of drivers have enough trouble keeping their cars on the road without putting slicks in the hands of people who have no idea how to use them safely.
 

lovegroova

Well-known Member
To be fair to Berties, he did ask about using slicks in places where there was no rain at all, so on that front, it's a reasonable question.

I know people who have cars that only ever use slick tyres (and only ever on dry track days), so that's an extreme example of what Berties is talking about.

However, Berties, even normal road tyres work better when warmed up a bit (and worse when they are overheated).

It's also worth mentioning that there may be places where it never rains, but other vehicles dump oil, diesel and all sorts of other nasty stuff on the tarmac, and slicks would be very bad in that scenario (see also Alex's leaky pipe above).
 

alexs2

Well-known Member
;) I'm glad someone (else) in here is able to read between the lines :smashin:
I check my pipes daily thank you!....comes in very useful when you're crossing the lines on wet slicks....
 

TRL

Banned
I suggest the op sits next to me while I drive my Merc at the limit of my abilities, with ESP off, next summer. I doubt he will feel the need for a fraction more grip or traction.

To the op: what sort of driving do you do? Which car do you drive?
 
Status
Not open for further replies.

The latest video from AVForums

Podcast: Trinnov Room Optimiser: A full explanation of Trinnov and its room optimiser technology
Subscribe to our YouTube channel

Latest News

Samsung teases 76-inch MicroLED TV plus flagship Q950A soundbar
  • By Andy Bassett
  • Published
Amazon Music fully available on Android TV and Google TV platforms
  • By Andy Bassett
  • Published
Sony announces A90J UK/EU price and March availability
  • By Andy Bassett
  • Published
AVForums Podcast: 27th February 2021
  • By Phil Hinton
  • Published
Musical Fidelity launches M3x Vinyl phono stage
  • By Andy Bassett
  • Published
Support AVForums with Patreon

Top Bottom