Doug Milliken writes:
>>>>> I have heard that you cannot aqua plane on bikes because of the size of contact area versus
>>>>> weight. Is this true for all widths of tyre incl 1.5inch? (assuming a pressure of 70psi or so)
>>>> Speed is also a factor. To get an intuitive feel for what you would need to do to aquaplane on
>>>> a bike, imagine how fast you would have to run at a puddle of water such that when you reached
>>>> it you could aquaplane (not
>>> Surface is also a factor, a smooth steel plate (used around here during road repairs) is very
>>> slippery when wet.
>> Let's not confuse lubrication and flotation as in aqua/hydro-planing. In lubrication, mating
>> surfaces and the lubricant work together while in hydroplaning the surface, such as pavement
>> roughness, plays no role. As has been discussed often, a squeegee with a sharp rubber edge glides
>> effortlessly over glass on a few molecular layers of water. That is lubrication in contrast to
>> tires lifting off the road over water.
> Thanks for the clarification. Just wanted to point out that even though bike tires don't
> hydroplane, doesn't mean they will always grip on a wet surface. For another example, some places
> (ie, England) use tar to patch, and this can leave a very smooth (almost glassy) surface.
I think crack patching is done with smooth tar in most places. Enough riders have slipped on the
stuff around here, both up hill and down, the latter being more damaging. However, in France these
tar stripes are covered with a grey-green grit to improve traction. The problem with this material
is that it uses slow curing tar that presents a sliding problem itself as it can move laterally when
not yet cured.
Jobst Brandt
[email protected] Palo Alto CA
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