On the subject of tyres

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AUbicycles
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Re: On the subject of tyres

Postby AUbicycles » Mon Feb 05, 2018 8:15 am

Thoglette, average and max speeds make it a different game as well. Grip is more integral in motor racing, is is core to the strategy (driving behaviour).

In the cycling world, treads and tyre pressure is the way to influence traction - offroad is has the biggest impact - while the material properties contribute, this is not where the primary gains or losses can be made.

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Re: On the subject of tyres

Postby Thoglette » Mon Feb 05, 2018 2:04 pm

AUbicycles wrote:Grip is more integral in motor racing, is is core to the strategy (driving behaviour).


Stumbled over some photos that underline how different the two worlds you're talking about are.

While this photo of Cadel looks like he's trying hard
Image
From Dave Moulton

..a quick comparison to someone cornering hard shows that he's not even trying. Well he is, just that the grip is not there (because it's not important compared to other things)
Image
Fine Art America, Kevin Schwantz Photograph by Tom Hnatiw

Perhaps 0.7G vs about 1.2G. And Kevin hasn't even got his elbow down yet.

Importantly, it's not just the tyres that make grip. There's a whole raft of things going on in the compromise between safe cornering speed and maximising the use of Cadels V02.
Last edited by Thoglette on Mon Feb 05, 2018 2:13 pm, edited 2 times in total.
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Re: On the subject of tyres

Postby eeksll » Mon Feb 05, 2018 2:09 pm

A slight tangential question, am I as a rider going to perceive/feel any difference on a tyre that is grippier over one that is less grippy, but going at the same speed to not lose grip on either tyre.

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Re: On the subject of tyres

Postby Thoglette » Mon Feb 05, 2018 2:19 pm

eeksll wrote:A slight tangential question,

Now there's a can of worms! There's no easy answer
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Re: On the subject of tyres

Postby mikesbytes » Mon Feb 05, 2018 2:43 pm

Thoglette wrote:
eeksll wrote:A slight tangential question,

Now there's a can of worms! There's no easy answer
Agree there

A bigger difference is your confidence in the wet. For me personally I've found that once endurance compounds start sliding in the wet, they become very hard to control where sports compounds make much easier to re-find the grip before you kiss the tarmac.

Before we digress further, is should be pointed out that tyre pressure and the positioning of your body make a huge difference in wet weather grip
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Re: On the subject of tyres

Postby bychosis » Mon Feb 05, 2018 2:46 pm

eeksll wrote:A slight tangential question, am I as a rider going to perceive/feel any difference on a tyre that is grippier over one that is less grippy, but going at the same speed to not lose grip on either tyre.

While I think that I am fairly mechanically sympathetic and can feel changes in how my bikes (and motorised toys) handle, I have rarely been able to feel the difference in bicycle tyre grip, or even reasonable changes in tyre pressure.
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Re: On the subject of tyres

Postby uart » Mon Feb 05, 2018 2:46 pm

eeksll wrote:A slight tangential question, am I as a rider going to perceive/feel any difference on a tyre that is grippier over one that is less grippy, but going at the same speed to not lose grip on either tyre.


I don't think that you are gong to notice much until you actually lose grip. But you don't have to come off in a corner to lose grip - I sometimes loss traction on the back wheel if I brake a bit too hard with the rear lever. So I find that I can (safely) tell the difference between a grippy and not so grippy tyre by just how hard I can brake on the rear without it skidding.

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Re: On the subject of tyres

Postby Jmuzz » Mon Feb 05, 2018 6:31 pm

eeksll wrote:A slight tangential question, am I as a rider going to perceive/feel any difference on a tyre that is grippier over one that is less grippy, but going at the same speed to not lose grip on either tyre.


You feel it the day you emergency stop or it lets go mid corner.

Will that day ever come? Hopefully not and sensible riding can manage the risks.
But if it does then the better grip, or more precise control of disk brakes etc could be something you wish for in hindsight.

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Re: On the subject of tyres

Postby find_bruce » Mon Feb 05, 2018 7:29 pm

Wonder if we could start an April Fools story that Di3 will feature ABS and traction control

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Re: On the subject of tyres

Postby Kronos » Mon Feb 05, 2018 8:00 pm

Jmuzz wrote:
eeksll wrote:A slight tangential question, am I as a rider going to perceive/feel any difference on a tyre that is grippier over one that is less grippy, but going at the same speed to not lose grip on either tyre.


You feel it the day you emergency stop or it lets go mid corner.

Will that day ever come? Hopefully not and sensible riding can manage the risks.
But if it does then the better grip, or more precise control of disk brakes etc could be something you wish for in hindsight.


I've felt it the last few days up the hill section at Gyndier Drive there are leaves and debris all over the place since they've closed off that road, it has been wet on the Sunshine Coast of late. In the end it comes down to how you handle the situation. A lot of people would panic as soon as they notice a slip and grab some more brake at the first bump/slide in the damp and end up sliding out even worse. In this instance the answer is one of less is more.

The key with all things rear wheel drive is to actually power through the slide and not panic. It's when you panic that you're going to go arse over tit. It may sound counter-intuitive but If your wheel starts sliding, release the brakes and allow for the possibility of the tyre to regain traction. Then if the wheel regains traction carry on, on your merry way. Too many people panic and lose all common sense when they're out riding or driving a car for that matter. You have to train yourself not to panic and to respond to the situation in a controlled fashion.

It is recoverable, it's about how you choose to deal with the situation.

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Re: On the subject of tyres

Postby Philistine » Mon Feb 05, 2018 9:01 pm

Derny Driver wrote:I don't watch it. Last F1 race I saw was when Ayrton Senna was racing. :?


I think Formula One was in decline as a spectacle from the early sixties. Former Lotus boss Colin Chapman single-handedly advanced the science of handling and roadholding by about fifty years, seemingly over night. As cars became faster through corners, the opportunities for overtaking became progressively less, culminating in the processions we see now, where positional changes come about through pit stop strategy rather than on the track.

I would have paid good money to see Nuvolari strutting his stuff at the wheel of an Alfa P3 or perhaps an Auto Union, but I don't bother turning the telly on for Formula One any more.

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Re: On the subject of tyres

Postby eeksll » Mon Feb 05, 2018 11:56 pm

Philistine wrote:... but I don't bother turning the telly on for Formula One any more.


we don't get it anymore.

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Re: On the subject of tyres

Postby AUbicycles » Tue Feb 06, 2018 5:02 am

I tend to notice that my tyre pressure is lower but the way the bike goes over changing surfaces for example a grate in the road of from thick side stripes onto regular bitumen. For fast descents and cornering, if it feels spongy racking up the g-forces, that is also a tell-tale sign. It is probably about knowing how my bike should feel and handle and getting the subtle input.

On the MTB it is easier to recognise if the pressure is too low or high for the trail.

On slippage, don’t panic. Main thing us to keep the front wheel turned in the direction you want to go, ease off the acceleration and keep balanced - watch the weight distribution. I had a lot of practice on the weekend as it snowed (yes I am OS) and the higher I climbed the slipperier it got. Once the bike ended and I knew the rest of the way was onroad in the mush and slush with cars about, I decided to call it a day. I am on 25mm and even around the slightest curve, low speeds and keeping dead upright is crucial. You can check my intagram (@bicyclesnetau) for a few photos or on strava can see an image of my ice-caked brakes.

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