In The Wet
With a pair of modern road tyres, the grip you’ll get even in the wet is amazing.
Q?: So just how much grip is there in the wet?
A: Quite a lot more than riders expect. Getting technical its all to do with the co-efficient of friction (COF) on roads and on a good dry road we would expect a COF of around 0.7 If the road is wet, the COF would be about 0.5 and if it was icy you’d get about 0.1.
Q? So 0.7 to 0.5 doesn’t sound like a great difference
A; Looking at the numbers no, but it is about 30% That’s not a not a huge reduction. Yet if you were to look at riders’ percentage speed reduction when it rains its often greater than that. I see it all the time. The rain starts and their shoulders tense up and suddenly they ride very slowly, not exploiting any grip at all.
Q? Is it common to tense up
A: Absolutely. I often see tension start to build in rider’s shoulders, and then they lock out their elbows. That indicates to me that the ride is going to go downhill a bit. You can only ride well and learn when you are relaxed. Sometimes I stop the ride and get the rider to do a few relaxing exercise with the arms. If they just relaxed and put more trusted their tyres it could just turn out to be fun.
Q? Are some parts of the road grippier in the wet than others
A: There are always parts of the road that give better grip. Watch a racer in the rain, cars or bikes, they go looking for different lines in search of grip. Sometimes we have to too. Roads are made up of aggregate and tar to hold it together. The stones give the grip. So when its wet I seek out the rougher gripper sections of road rather than the part that’s been worn and polished by traffic. I then have to balance that new line against how it may have changed my view. So in the wet I seek out the grip and in the dry I seek out the view.
Q? So my corning line would be different in the wet
A: Almost always. If the road is dry and the surface is giving me all the grip I can use, and more, then I am always looking for the perfect view. If that same piece of road is wet then I’ll give up some of that view for better grip. My speed will be slightly reduced so loosing some of that view is negated. Remember you still need to stop within the distance you can see to be clear on your side of the road and your very best chance to do that is on the grippy rough surface.
Q? How about at a roundabouts. Do you still straight line it
A: I apply the same principal as for cornering You are still. looking for the line that keeps you the most upright because there could probably oil and diesel and you don’t want to be leant over, so that might mean you take your usual line, only slower.
I avoid manhole covers and white lines too Look early and plan to avoid them and then not look at them again.
Q? How do you know you have enough grip in the wet
It’s difficult. You’re looking for feedback. Some tyres give feedback some don’t even though both may have similar levels of grip you won’t be able to feel how much of it you have. As you approach the limit you may get a feeling of slight uneasiness, sometimes a mild floating sensation its there in the seat of your pants, quite literally. Don’t ignore that feeling.
Q? So what about tyres?
If you’ve got modern tyres, there is absolutely no reason why you can’t enjoy a brisk, smooth, enjoyable ride in the wet. Icy roads are of course a different matter. That’s just a lottery.