Sunday 31 October 2021

Quiz: Match the tyre to it's rolling resistance numbers

Here are five tyres and five rolling resistance power losses.  Higher rolling resistance losses mean the tyres are 'slower'.

Which rolling resistance number corresponds to which tyre?  Have a guess.

Beware though, looks can be deceiving.  The answers are at the bottom of this blog post.




When friends, especially beginner cyclists, ask me for advice about their bikes, one of my first suggestions is to get good tyres.  It's difficult to convince them though, to convey the differences between a fast tyre versus a slow tyre.  Many road tyres look outwardly identical.  There is a temptation to judge the rolling resistance of a tyre by it's tread, it's width or it's pressure.  There's much more to it than that, though.

For example, Tyres #1 and #2 look similar. They are both slicks, and their width and pressures are identical. They must perform similarly then, right?  The MTB tyre on the top right must be slow, because it's wide soft and is knobbly, right?

These pre-conceptions mean that many people make poor tyre choices, or don't realise the consequences of their tyre choice.  It doesn't have to be that way.  With a bit of time, independent tyre test data can be found on the internet - rolling resistance data like the data used and presented in this blog post - allowing anyone to make an informed and wise decision about where to spend their money and what tyres to buy.

Two good sources on independent data are:

https://www.bicyclerollingresistance.com/

http://bikeblather.blogspot.com/


Results of the quiz are shown below.

Who would have guessed a knobbly MTB tyre at 25psi has a significantly lower rolling resistance than a slick 23mm road tyre at 80 psi?  Take care though, because this is one of the fastest MTB tyres, being compared to one of the slowest road tyres.

Nevertheless, I'm sure you'll agree, looks can be deceiving...


 

1 comment:

  1. I got them all right. Please can you do another one and make it harder? :-)

    ReplyDelete