Hello, and welcome to PowerDrift, this is a series we call Simplified, where we take
complicated automotive ideas and we break them down into something you can use,
and one of the most common questions we get on PowerDrift is, can I put a larger tyre on
the back of my motorcycle?
So let's get right into it, but before that, please do hit the subscribe button, and do
hit the bell notification icon so that content like this can find you easily and if you like
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So, should you be putting a larger tyre on the back of your motorcycle?
And honestly, the answer is no, you should not, and thank you so much for watching.
No, it's not over, the reason why I'm saying that is because when the manufacturer designs
the motorcycle, they have a role for the motorcycle in their minds and what they want to do is
create a tyre setup that does that job as well as possible within the cost constraints
and at as low cost as possible, but, that's the slightly cynical way to look at it, what they're
also trying to do is ensure that you have the most optimal experience as possible and
the word optimal is important, because the bigger tyre, less fuel economy, bigger tyre,
less acceleration, bigger tyre more weight, so you can't really keep making the tyres larger.
And remember, just like everything else on a motorcycle, the tyre has a job to do and
the reason why they pick a certain size for a motorcycle or a scooter is because it's
doing that particular job, so, what is a tyre supposed to do?
Now the fundamental job of a tyre obviously, is to give you a lot of grip, right, you want
the grip at the front so that you can brake hard, you want the grip at the front, you
can turn the motorcycle as sharply as you dare.
You want grip at the back so that you can drive the motorcycle forward and obviously
in a corner, the front is important, but the rear also has a job to do and the first thing
I want to tell you and it's funny is that 99% of the time the motorcycle you're riding
has tyres that are better than you are as a rider.
This was not the case, in the early 2000s when I started testing, there were really
really poor tyres out there,
but today, almost any motorcycle you can name has tyres that will outperform you 99% of the time.
So first, if you're complaining saying I need a bigger tyre because I don't feel stable
and I don't have enough grip, what you're basically saying is that your throttle control,
your control over the motorcycle itself is not evolved enough for you to be able to use
that tyre a lot.
And if that control does not evolve, putting a better tyre is only going to be a stopgap
measure at best, it's not the solution, the solution is for you to learn how to ride the
motorcycle better.
This is not a easy truth to assimilate, but it's absolutely 100% true.
Put a fast guy on your motorcycle, a guy who knows what he's doing and he will show you
that that tyre is actually capable of a lot and the width of the tyre has literally nothing
to do with it in most cases and just to take an example out of thin air, look at the videos
of people racing step throughs in Thailand, they race really, really narrow tyres, the
lean angles are not inconsequential and they do it because they trust the tyres, they have
the skill and the tyres are very grippy and it's true for most tyres on sale today.
But let's say that you ignored this advice and you said now I want to oversize it anyway,
the first thing to consider is how much are you oversizing by, if you're oversizing more
than one size up, so a 100 becoming 110 section, if you're doing more than that,
think about the size of the rim
because if your rim is the same size and you put an ever-larger tyre is basically pinching
the tyre.
If it pinches the tyre like this, you don't really get a larger contact patch out of it,
you visually might get a slightly larger looking tyre, but it doesn't do any work at all.
In fact, it does a lot of detrimental stuff because a bigger tyre is going to be more
expensive, it's going to be heavier, heavy means your fuel economy, your performance
and handling, all three will go down by some measure or the other and remember, tyres are
part of the unsprung mass of the motorcycle.
If you don't know what that is, stay tuned we have a video on sprung and unsprung mass
coming up on Simplified, but if you keep increasing the unsprung mass on your motorcycle, it'll
just keep feeling worse.
One of the best places to lose weight on a motorcycle, in fact, is the unsprung mass
where you take the rim, the brakes or the tyres and you try to lose weight from there,
oversizing tyres does not do that.
Let's assume that you weren't being parsimonious about the rim and you said yes, I'm oversizing
say by three or four sections, so the 100 is now becoming 130 or 140 section tyre and
you're willing to invest in the rim that is right for that size.
Now the question becomes, does it actually fit into your motorcycle because remember,
motorcycle manufacturers have no incentive to make a motorcycle super flexible in this
particular way.
So the swing arms, the gap in the swingarm is designed, the gap between the two fork
legs is also designed to take the size that they design the motorcycle for, so if you
go 3, 4, 5 sections up, you may not actually physically be able to fit this into the motorcycle
without changing the swingarm.
To me messing with structural parts on the motorcycle, things like the swingarm, it's
just something that is a bad idea, if you have a very, very good mechanic who's super
capable and super talented, this can be done, but most of the cases I would simply tell
you that it's just not worth the effort.
The third thing that happens and this is a very strange consequence, which most people
don't realise is that when you make the tyre wider, you have to lean the motorcycle more
for the same corner.
The simple piece of logic is, if you draw a line through the centreline of the tyre,
and you look at how far the edge of the tyre is from the centreline, the bigger the tyre,
the bigger this distance becomes, the bigger this distance is, the more you have to lean
the motorcycle to get to that edge of the tyre and therefore, either you're going to
have really large chicken strips and your friends will laugh at you, the lean angles
will scare you, worst case, you'll just be using a lot more effort to get to the same
corner that you did on a larger tyre.
This is why when they build a drag race motorcycle with a 240 section rear tyre, they can because
they don't intend to lean the motorcycle at all.
In fact, one of the amazing things about bikes like the Ducati Diavel is that they run that
240 section on the back, but it was designed to run it from the beginning, so the chassis
has been tuned to allow the tyre to work.
If you were to take a current normal motorcycle, let's take the RSV4 which uses a 190 or a 200
section rear tyre and put of 240 section tyre on the back, that would become the world's
worst RSV4 in one heartbeat because it would not lean, it would feel heavy, it would not
go the same way and that RSV4's engine, anyways a thirsty engine, it would drink even more fuel.
So, to sum this up, if you want to oversize a tyre, you might have to change the rim,
after you do that it may or may not fit into the motorcycle, so that's the physical challenge
of over sizing your tyre.
The only pro to oversizing a tyre is if you have a really powerful motorcycle and you're
having trouble delivering all of that power to the ground.
That's the reason why a manufacturer puts a 200-section tyre on a 200bhp motorcycle,
there is literally no other reason to do it.
To give you a personal example, my Tuono, on the manual, it says if you're taking the
motorcycle to the racetrack and you're using a very sticky tyre like the Super Corsa, you
want to run a 200 section at the back, but for everything else, we recommend that you
go down to a 190 section and the reason is because the 200 section will allow you to
put a lot of torque and horsepower down on the ground, which is very important at a racetrack.
The reason to not upsize your tyre, there are tonnes of reasons but the top five I think
on my list, are it's heavier, so it's going to make your motorcycle feels slower to go, it's
heavier, so it will make your motorcycle slower to steer, you're going to spend money on it
which could have used on petrol and gone a longer distance with it rather than doing
this silly thing and I get that this is an aspirational thing that you see these big
bikes with their 190, 200 section rear tyres and you say that's what I'd like on my motorcycle,
but I promise you, go large enough and your motorcycle will just not go, it will become
something that you look at and if you just wanted to look at motorcycles, that's what
motorcycling museums are for, we buy motorcycles to ride them.
Thank you so much for watching, this is Simplified, this is PowerDrift, if you'd like to discuss
this in more detail, leave us a comment.
If there's other topics you'd like us to talk about, leave us a comment and I invite you
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Thank you so much for watching.