OFF!

Deadeye Duck

Shoulder of Lamb wrote:

I'd like to believe the oil slick theory as that eliminates rider error and/or bike or tyre failure.

I looked closely at the patch of tarmac I went over on this morning and even in the dry it's very smooth, almost shiny. It's a dangerous bit of road in the wet.

Unfortunately for me I think this accident was mainly my fault for going too fast. The condition of the road did not help. The weather conditions did not help. The tyres are an open question - I just feel they seem more slippery than my previous bontrager select when cornering in the wet. The bonty's had a massive bald patch on them when replaced as well as other bald areas, I feel they put more rubber down onto the tarmac and therefore provide more grip. But the corollary to this is they have poor puncture resistance. I have had no problems with the Continetals in the dry and my commute today was fine - I paid particular attention to cornering and they were super-smooth and grippy around the bends.

I am fine. I did not go to hospital because I could not bear the hours sitting in casualty to be told I'm fine. I have a nasty graze on my hip, but that's it. It stings a bit, but I have treated it with wound wash and it has a large plaster over it. I'm going to be fine. Luckily it does not inhibit my cycling in any way. I set a PB on the way home last night (with tailwind and reduced traffic due to the hour).

Be careful out there...

A few words of advice mate. The more patterns in the tyres tread, generally, the more grip you'll have in the wet.

Slicks are excellent in the dry, they heat up and grip to the road like glue, but if there's any wet on the road at all, you'll just slide over the road like it's made of ice. You need the groves to displace the water away from between your tyre and the ground to get grip. This is why in motor racing etc, you'll only ever see tread on the tyres of the cars/motorbikes, if the track will be wet.

il_principe

Deadeye Duck wrote:

A few words of advice mate. The more patterns in the tyres tread, generally, the more grip you'll have in the wet.

Slicks are excellent in the dry, they heat up and grip to the road like glue, but if there's any wet on the road at all, you'll just slide over the road like it's made of ice. You need the groves to displace the water away from between your tyre and the ground to get grip. This is why in motor racing etc, you'll only ever see tread on the tyres of the cars/motorbikes, if the track will be wet.

Not actually the case Deadeye:

As Sheldon says:

Tread for on-road use

Bicycle tires for on-road use have no need of any sort of tread features; in fact, the best road tires are perfectly smooth, with no tread at all!

Unfortunately, most people assume that a smooth tire will be slippery, so this type of tire is difficult to sell to unsophisticated cyclists. Most tire makers cater to this by putting a very fine pattern on their tires, mainly for cosmetic and marketing reasons. If you examine a section of asphalt or concrete, you'll see that the texture of the road itself is much "knobbier" than the tread features of a good quality road tire. Since the tire is flexible, even a slick tire deforms as it comes into contact with the pavement, acquiring the shape of the pavement texture, only while incontact with the road.

People ask, "But don't slick tires get slippery on wet roads, or worse yet, wet metal features such as expansion joints, paint stripes, or railroad tracks?" The answer is, yes, they do. So do tires with tread. All tires are slippery in these conditions. Tread features make no improvement in this.

And from Wiki:

Wet traction is improved by the tread design's ability to channel water out of the tire footprint and reduce hydroplaning. However, tires with a circular cross-section, such as those found on racing bicycles and motorcycles, when properly inflated have a sufficiently small footprint to not be susceptible to hydroplaning. For such tires, it is observed that fully slick tires will give superior traction on both wet and dry pavement.

lost_in_thought

Now, futher to IP's post above, I have a question...

I was told, in the context of car tyres, that the softer rubber compounds wear out more quickly, but grip better. Harder compounds have greater resistance to damage from poor surfaces, and wear out more slowly, but don't grip nearly as well. My mechanic friend refers to my tyres as 'ditchfinders' for this reason, which I find quite funny. Harder compound tyres are also cheaper, so I tend to buy them!

Now, does the same wisdom apply to bike tyres? When you're buying a p*ncture-resistant tyre, are you getting a harder rubber compound, and thereby less grip, compared to a tyre that's perhaps less p*ncture-resistance focussed?

Deadeye Duck

Hmm, never knew that it didn't apply to circular tyres. When I raced motorbikes, I could definitely tell the difference between treaded and slick in the wet. This could have something to do with the extra speed though, I guess...

il_principe

Deadeye Duck wrote:

Hmm, never knew that it didn't apply to circular tyres. When I raced motorbikes, I could definitely tell the difference between treaded and slick in the wet. This could have something to do with the extra speed though, I guess...

Think about the differences in contact patch size though... I think perhaps the wiki comment re bikes is misleading but:

A car tire is quite wide, so water from the middle of the contact patch can have trouble escaping as the tire rolls over it, if there are not grooves to let it escape. A bicycle tire is narrower, so not as much water is in contact with the leading edge at once.
Car tires run at much lower pressure than bicyles. The high pressure of bicycle tires is more efficient at squeezing the water out from under.
Cars go much faster than bicycles, again leaving less time for water to escape. At high bicycle speeds, hydroplaning is just possible for car tires, but is absolutely impossible for bicycle tires.

il_principe

lost_in_thought wrote:

Now, futher to IP's post above, I have a question...

I was told, in the context of car tyres, that the softer rubber compounds wear out more quickly, but grip better. Harder compounds have greater resistance to damage from poor surfaces, and wear out more slowly, but don't grip nearly as well. My mechanic friend refers to my tyres as 'ditchfinders' for this reason, which I find quite funny. Harder compound tyres are also cheaper, so I tend to buy them!

Now, does the same wisdom apply to bike tyres? When you're buying a p*ncture-resistant tyre, are you getting a harder rubber compound, and thereby less grip, compared to a tyre that's perhaps less p*ncture-resistance focussed?

Not sure tbh, but most puncture protection is dealt with by the layers under the rubber, rather than the rubber itself.

biondino

The Chingford Skinhead wrote:

SoL - hope you're not too sore in the morning. Get well soon.

I found my Marathon + tyres are a bit skittish in the rain as well - maybe it's just the price you pay for the puncture protection

My Schwalbe Ultremos have gone 3000 miles without a puncture yet. You really do pay a high price with those tractor tyres

Deadeye Duck

Il Principe wrote:

lost_in_thought wrote:

Now, futher to IP's post above, I have a question...

I was told, in the context of car tyres, that the softer rubber compounds wear out more quickly, but grip better. Harder compounds have greater resistance to damage from poor surfaces, and wear out more slowly, but don't grip nearly as well. My mechanic friend refers to my tyres as 'ditchfinders' for this reason, which I find quite funny. Harder compound tyres are also cheaper, so I tend to buy them!

Now, does the same wisdom apply to bike tyres? When you're buying a p*ncture-resistant tyre, are you getting a harder rubber compound, and thereby less grip, compared to a tyre that's perhaps less p*ncture-resistance focussed?

Not sure tbh, but most puncture protection is dealt with by the layers under the rubber, rather than the rubber itself.

Now I'm almost certain I know this one

grip in proportion to compound is to do with how quickly the tyre can heat up and form to the shape of the road it's rolling over. For this reason, softer compound tyres don't last as long as harder compounds because they wear away a lot faster due to the rolling temps and shredding recieved by going over the tarmac. Harder compounds rarely reach the same temps and so don't form to the shape of the tarmac as easily as the softer compounds, thus leading to less grip. Best way to think about this is to think of toffee. (stay with me on this one). Toffee when hard you could rub it up and down a grater and it would take a while to get rid of it but it would move pretty easily over the grater. Toffee when soft would be gone in less than half the strokes but would be a lot more work to move it up and down the grater as it would be sticking to it at the same time.